Siemens Siprotec 7UM611, Siprotec 7UM612 User Manual

Download

SIPROTEC

www . ElectricalPartManuals . com

Preface

Introduction 1 Functions 2 Mounting and Commissioning 3

Multi-Functional Generator Protection Relay 7UM61

V4.1

Manual

Technical Data 4 Appendix A

Literature

Glossary

Index

C53000-G1176-C127-3

Disclaimer of liability

www . ElectricalPartManuals . com

We have checked the text of this manual against the hardware and software described. However, deviations from the description cannot be completely ruled out, so that no liability can be accepted for any errors or omissions contained in the information given.

The information in this manual is checked periodically, and necessary corrections will be included in future editions. We appreciate any suggested improvements.

We reserve the right to make technical improvements without notice.

Copyright

Dissemination or reproduction of this document, or evaluation and communication of its contents, is not authorized except where expressly permitted. Violations are liable for damages. All rights reserved, particularly for the purposes of patent application or trademark registration.

Registered Trademarks

SIPROTEC, SINAUT, SICAM and DIGSI are registered trademarks of SIEMENS AG. Other designations in this manual may be trademarks that if used by third parties for their own purposes may violate the rights of the owner.

4.10.05

7UM61 Manual

C53000-G1176-C127-3

Preface

www . ElectricalPartManuals . com

Purpose of this Manual

Target Audience Protection engineers, commissioning engineers, personnel concerned with adjust-

Applicability of this Manual

Indication of Conformity

This manual describes the functions, operation, installation, and commissioning of the device 7UM61. In particular it contains:

• Information regarding the configuration of the device extent and descriptions of

device functions and settings → Chapter 2;

• Instructions for mounting and commissioning → Chapter 3;

• Compilation of technical data→ Chapter 4;

• As well as a compilation of the most significant data for experienced users in Appendix A.

General information about design, configuration, and operation of SIPROTEC devices is laid down in the SIPROTEC

ment, checking, and service of selective protective equipment, automatic and control facilities, and personnel of electrical facilities and power plants.

This manual is valid for: Multi-Functional Generator Protection Relay with Local Control SIPROTEC

This product complies with the directive of the Council of the European Communities on the approximation of the laws of the Member States relating to electromagnetic compatibility (EMC Council Directive 89/336/EEC) and concerning electrical equipment for use within specified voltage limits (Low-voltage directive 73/23 EEC). This conformity has been proved by tests conducted by Siemens AG in accordance with Article 10 of the Council Directive in agreement with the generic standards EN 50081 and EN 61000-6-2 (for EMC directive) and the standard EN 60255-6 (for low-voltage directive). This device was designed and produced for industrial use according to the EMC standard. The product conforms with the international standard of the series IEC 60255 and the German standard VDE 0435.

4 7UM61; firmware version V4.1.

System Description /1/.

This product is UL-certified according to the Technical Data:

C53000-G1176-C127-3

37UM61 Manual

Preface

www . ElectricalPartManuals . com

Additional Support Should further information on the System SIPROTEC® 4 be desired or should partic-

ular problems arise which are not covered sufficiently for the purchaser's purpose, the matter should be referred to the local Siemens representative.

Training Courses Individual course offerings may be found in our Training Catalogue, or questions may

be directed to our training centre in Nuremberg.

Instructions and Warnings

The warnings and notes contained in this manual serve for your own safety and for an appropriate lifetime of the device. Please observe them! The following indicators and standard definitions are used:

DANGER

indicates that death, severe personal injury or substantial property damage will result if proper precautions are not taken.

Warning

indicates that death, severe personal injury or substantial property damage can result if proper precautions are not taken.

Caution

indicates that minor personal injury or property damage can result if proper precautions are not taken. This particularly applies to damage on or in the device itself and consequential damage thereof.

Note

indicates information about the device or respective part of the instruction manual which is essential to highlight.

WARNING!

When operating an electrical device, certain parts of the device inevitably have dangerous voltages.

Failure to observe these precautions can result in fatality, personal injury, or extensive material damage.

Only qualified personnel shall work on and around this equipment. It must be thoroughly familiar with all warnings and safety notices of this manual as well as with the applicable safety regulations.

The successful and safe operation of this device is dependent on proper handling, installation, operation, and maintenance by qualified personnel under observance of all warnings and hints contained in this manual. In particular the general erection and safety regulations (e.g. IEC, DIN, VDE, EN or other national and international standards) regarding the correct use of hoisting gear must be observed.

7UM61 Manual

C53000-G1176-C127-3

Definition QUALIFIED PERSONNEL

www . ElectricalPartManuals . com

For the purpose of this instruction manual and product labels, a qualified person is one who is familiar with the installation, construction and operation of the equipment and the hazards involved. In addition, he has the following qualifications:

• Is trained and authorized to energize, de-energize, clear, ground and tag circuits and equipment in accordance with established safety practices.

• Is trained in the proper care and use of protective equipment in accordance with established safety practices.

• Is trained in rendering first aid.

Typographic and Graphical Conventions

To designate terms which refer in the text to information of the device or for the device, the following fonts are used:

Parameter names

Designators of configuration or function parameters which may appear word-forword in the display of the device or on the screen of a personal computer (with operation software DIGSI also applies to header bars for selection menus.

1234A

Parameter addresses have the same character style as parameter names. Parameter addresses contain the suffix A in the overview tables if the parameter can only be set in DIGSI

Parameter Conditions

Possible settings of text parameters, which may appear word-for-word in the display of the device or on the screen of a personal computer (with operation software DIGSI selection menus.

“Annunciations”

Designators for information, which may be output by the relay or required from other devices or from the switch gear, are marked in a monospace type style in quotation marks.

), are additionally written in italics. This also applies to header bars for

via the option Display additional settings.

Preface

), are marked in bold letters of a monospace type style. This

7UM61 Manual C53000-G1176-C127-3

Deviations may be permitted in drawings and tables when the type of designator can be obviously derived from the illustration.

The following symbols are used in drawings:

Device-internal logical input signal

Device-internal (logical) output signal

Internal input signal of an analog quantity

External binary input signal with number (binary input, input indication)

External binary output signal with number (device indication)

Preface

www . ElectricalPartManuals . com

External binary output signal with number (device indication) used as input signal

Example of a parameter switch designated FUNCTION with the address 1234 and the possible settings ON and OFF

Besides these, graphical symbols are used according to IEC 60617-12 and IEC 60617-13 or symbols derived from these standards. Some of the most frequently used are listed below:

Input signal of an analog quantity

AND gate

OR gate

Exclusive–OR gate (antivalence): output is active, if only one of the inputs is active

Equivalence: output is active, if both inputs are active or inactive at the same time

Dynamic inputs (edge–triggered) above with positive, below with negative edge

Formation of one analog output signal from a number of analog input signals

Limit stage with setting address and parameter designator (name)

Timer (pickup delay T, example adjustable) with setting address and parameter designator (name)

Timer (dropout delay T, example non-adjustable)

Dynamic triggered pulse timer T (monoflop)

Static memory (RS-flipflop) with setting input (S), resetting input (R), output (Q) and inverted output (Q

■

)

7UM61 Manual

C53000-G1176-C127-3

www . ElectricalPartManuals . com

1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

1.1 Overall Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

1.2 Application Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1.3 Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2 Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.1 Introduction, Reference Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.1.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.2 Functional Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2.2.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2.2.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2.2.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

2.3 Power System Data 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2.3.1 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2.3.2 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

2.3.3 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

2.4 Change Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2.4.1 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2.4.2 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2.4.3 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2.5 Power System Data 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.5.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.5.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.5.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.5.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In . . . . . . . 42

2.6.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

2.6.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

2.6.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

2.6.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

C53000-G1176-C127-3

77UM61 Manual

Contents

www . ElectricalPartManuals . com

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection . . . . 46

2.7.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

2.7.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

2.7.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

2.7.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

2.8 Inverse-Time Overcurrent Protection (ANSI 51V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

2.8.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

2.8.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

2.8.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

2.8.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

2.9 Thermal Overload Protection (ANSI 49) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

2.9.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

2.9.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

2.9.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

2.9.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46) . . . . . . . . . . . . . . . . . . . . . . 70

2.10.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

2.10.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

2.10.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

2.10.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

2.11.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

2.11.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

2.11.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

2.11.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

2.12 Reverse Power Protection (ANSI 32R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

2.12.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

2.12.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

2.12.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

2.12.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

2.13 Forward Active Power Supervision (ANSI 32F). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

2.13.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

2.13.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

2.13.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

2.13.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

2.14 Impedance Protection (ANSI 21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

2.14.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

2.14.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

2.14.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

2.14.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

7UM61 Manual

C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

2.15 Undervoltage Protection (ANSI 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

2.15.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

2.15.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

2.15.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

2.15.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

2.16 Overvoltage Protection (ANSI 59) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

2.16.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

2.16.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

2.16.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

2.16.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

2.17 Frequency Protection (ANSI 81) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

2.17.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

2.17.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110

2.17.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

2.17.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112

2.18 Overexcitation (Volt/Hertz) Protection (ANSI 24). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113

2.18.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113

2.18.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115

2.18.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117

2.18.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117

2.19 Rate-of-Frequency-Change Protection df/dt (ANSI 81R) . . . . . . . . . . . . . . . . . . . . . . . . . . 118

2.19.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118

2.19.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119

2.19.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

2.19.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

2.20 Jump of Voltage Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

2.20.1 Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

2.20.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

2.20.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

2.20.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

2.21 90-%-Stator Earth Fault Protection (ANSI 59N, 64G, 67G) . . . . . . . . . . . . . . . . . . . . . . . . 128

2.21.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

2.21.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

2.21.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

2.21.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

2.22 Sensitive Earth Fault Protection (ANSI 51GN, 64R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

2.22.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

2.22.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

2.22.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

2.22.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

7UM61 Manual C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

2.23 100-%-Stator Earth Fault Protection with 3rd Harmonics (ANSI 27/59TN 3rd Harm.). . . . 140

2.23.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

2.23.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

2.23.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

2.23.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

2.24 Motor Starting Time Supervision (ANSI 48) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

2.24.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

2.24.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

2.24.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

2.24.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

2.25 Restart Inhibit for Motors (ANSI 66, 49Rotor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

2.25.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

2.25.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

2.25.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

2.25.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

2.26 Breaker Failure Protection (ANSI 50BF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

2.26.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

2.26.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

2.26.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

2.26.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

2.27 Inadvertent Energization (ANSI 50, 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

2.27.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

2.27.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

2.27.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

2.27.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

2.28 Measurement Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

2.28.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

2.28.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

2.28.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

2.28.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

2.29 Trip Circuit Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

2.29.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

2.29.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

2.29.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

2.29.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

2.30 Threshold supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

2.30.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

2.30.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

2.30.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

2.30.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

7UM61 Manual

C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

2.31 External Trip Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

2.31.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

2.31.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

2.31.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

2.31.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

2.32 RTD-Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

2.32.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

2.32.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

2.32.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

2.32.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

2.33 Phase Rotation Reversal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

2.33.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

2.33.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

2.34 Protection Function Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

2.34.1 Pickup Logic of Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

2.34.1.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

2.34.2 Tripping Logic of Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

2.34.2.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

2.34.2.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

2.34.3 Fault Display on the LEDs/LCD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

2.34.3.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

2.34.3.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

2.34.4 Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

2.34.4.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

2.34.4.2 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

2.35 Ancillary Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

2.35.1 Processing of Annunciations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

2.35.1.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

2.35.2 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211

2.35.2.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211

2.35.2.2 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

2.35.3 Set Points (Measured Values) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

2.35.3.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

2.35.3.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

2.35.3.3 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

2.35.4 Oscillographic Fault Records. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

2.35.4.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

2.35.4.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

2.35.4.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

2.35.4.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

2.35.5 Date and Time Stamping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

2.35.5.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

2.35.6 Commissioning Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

2.35.6.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

7UM61 Manual C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

2.36 Command Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

2.36.1 Control Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

2.36.1.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

2.36.2 Types of Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

2.36.2.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

2.36.3 Command Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

2.36.3.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

2.36.4 System Interlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

2.36.4.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

2.36.5 Command Logging/Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

2.36.5.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

3 Mounting and Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

3.1 Mounting and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

3.1.1 Configuration Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

3.1.2 Hardware Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

3.1.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

3.1.2.2 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

3.1.2.3 Switch Elements on the PCBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

3.1.2.4 Interface Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

3.1.2.5 Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

3.1.3 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

3.1.3.1 Panel Flush Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

3.1.3.2 Rack Mounting and Cubicle Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253

3.1.3.3 Panel Surface Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

3.2 Checking Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

3.2.1 Checking Data Connections of Serial Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

3.2.2 Checking Device Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

3.2.3 Checking System Incorporation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

3.3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262

3.3.1 Test Mode and Transmission Block . . . . . . . . . . . . . . . . . . . . 263

3.3.2 Testing System Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

3.3.3 Checking the Binary Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

3.3.4 Testing Circuit Breaker Failure Protection . . . . . . . . . . . . . . . . . . . . . 268

3.3.5 Testing User-defined Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268

3.3.6 Trip/Close Tests for the Configured Operating Devices . . . . . . . . . . . . . . . . 268

3.3.7 Commissioning Test with the Machine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

3.3.8 Checking the Current Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

3.3.9 Checking the Voltage Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

3.3.10 Checking the Stator Earth Fault Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276

3.3.11 Checking the Sensitive Earth Fault Protection when Used for Rotor Earth Fault Protec-

tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

3.3.12 Tests with the Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

3.3.13 Setup of a test fault recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

3.4 Final Preparation of the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291

7UM61 Manual

C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

4 Technical Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

4.1.1 Analog Inputs/Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

4.1.2 Auxiliary Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

4.1.3 Binary Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296

4.1.4 Communication Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

4.1.5 Electrical Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301

4.1.6 Mechanical Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303

4.1.7 Climatic Stress Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

4.1.8 Deployment Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

4.1.9 Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305

4.1.10 Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305

4.2 Definite-Time Overcurrent Protection (I>, ANSI 50/51; I>>, ANSI 50/51/67) . . . . 306

4.3 Inverse-Time Overcurrent Protection (ANSI 51V) . . . . . . . . . . . . . . . . . . . . . . . . . . 308

4.4 Thermal Overload Protection (ANSI 49) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

4.5 Unbalanced Load (Negative Sequence) Protection (ANSI 46) . . . . . . . . . . . . . . . . 317

4.6 Underexcitation (Loss-of-Field) Protection (ANSI 40) . . . . . . . . . . . . . . . . . . . . . 319

4.7 Reverse Power Protection (ANSI 32R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320

4.8 Forward Active Power Supervision (ANSI 32F) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

4.9 Impedance Protection (ANSI 21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

4.10 Undervoltage Protection (ANSI 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323

4.11 Overvoltage Protection (ANSI 59) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

4.12 Frequency Protection (ANSI 81) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

4.13 Overexcitation (Volt/Hertz) Protection (ANSI 24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

4.14 Rate-of-Frequency-Change Protection df/dt (ANSI 81R) . . . . . . . . . . . . . . . . . . . . . . . 328

4.15 Jump of Voltage Vector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

4.16 90-%-Stator Earth Fault Protection (ANSI 59N, 64G, 67G) . . . . . . . . . . . . . . . . . . . . 330

4.17 Sensitive Earth Fault Protection (ANSI 51GN, 64R) . . . . . . . . . . . . . . . . . . . . . . . . . . . 331

4.18 100-%-Stator Earth Fault Protection with 3rd Harmonics (ANSI 27/59TN 3rd Harm.) . 332

4.19 Motor Starting Time Supervision (ANSI 48) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333

4.20 Restart Inhibit for Motors (ANSI 66, 49Rotor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334

4.21 Breaker Failure Protection (ANSI 50BF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

4.22 Inadvertent Energization (ANSI 50, 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336

4.23 RTD-Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

4.24 Auxiliary Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338

7UM61 Manual C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

4.25 Operating Ranges of the Protection Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343

4.26 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345

4.26.1 Panel Flush and Cubicle Mounting – 7UM611 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345

4.26.2 Panel Flush and Cubicle Mounting – 7UM612 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

4.26.3 Panel Flush Mounting – 7UM611 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347

4.26.4 Panel Flush Mounting – 7UM611 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347

4.26.5 Dimensions of Coupling Unit 7XR6100-0CA0 for Panel Flush Mounting . . . . . . . 348

4.26.6 Dimensions of Coupling Unit 7XR6100-0BA0 for Panel Flush Mounting . . . . . . . . . . . . . 349

4.26.7 Dimension diagrams 3PP13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350

A Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351

A.1 Ordering Information and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

A.1.1 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

A.1.1.1 7UM61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

A.1.2 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354

A.2 Terminal Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357

A.2.1 General Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357

A.2.2 General Diagram (Surface Mounting Version). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358

A.2.3 General Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

A.2.4 General Diagram (Surface Mounting Version). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360

A.3 Connection Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361

A.3.1 Connection Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361

A.3.2 Connection Examples for Thermobox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370

A.3.3 Schematic Diagram of Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

A.4 Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

A.4.1 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

A.4.2 Binary Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

A.4.3 Binary Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374

A.4.4 Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

A.4.5 Default Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

A.4.6 Pre-defined CFC Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376

A.5 Protocol-dependent Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377

A.6 Functional Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378

A.7 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380

A.8 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391

A.9 Group Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407

A.10 Measured Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408

7UM61 Manual

C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .411

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421

7UM61 Manual C53000-G1176-C127-3

Contents

www . ElectricalPartManuals . com

7UM61 Manual

C53000-G1176-C127-3

Introduction 1

www . ElectricalPartManuals . com

The SIPROTEC® 7UM61 devices are introduced in this section. An overview of the 7UM61 is presented with its application areas, features, and scope of functions.

1.1 Overall Operation 18

1.2 Application Scope 21

1.3 Characteristics 23

C53000-G1176-C127-3

177UM61 Manual

1 Introduction

www . ElectricalPartManuals . com

1.1 Overall Operation

The digital Multi-Function Protection SIPROTEC® 7UM61 is equipped with a high performance microprocessor. All tasks such as the acquisition of the measured values and issuing of commands to circuit breakers and other switching equipment, are processed digitally. Figure 1-1 shows the basic structure of the device.

Analog Inputs The measuring inputs (MI) are galvanically isolated, transform the currents and volt-

ages from the primary transformers and adapt them to the internal processing level of the device. The device has 4 current and 4 voltage inputs. Three inputs are used on each side of the protected object for measuring of the phase currents.

Figure 1-1 Hardware Structure of the Digital Machine Protection Device 7UM61 (maximum configuration)

1 current input is equipped with sensitive input transformers (IEE) and can measure secondary currents in the mA range. 3 voltage inputs acquire the phase-to-earth voltages (connection to phase-to-phase voltages and voltage transformers in V connec-

7UM61 Manual

C53000-G1176-C127-3

1.1 Overall Operation

www . ElectricalPartManuals . com

tion is possible as well). The 4th voltage input is for displacement voltage measurement for stator earth fault protection.

The IA input amplifier group allows high impedance connection for analog input values and contains filters optimized for measured value processing bandwidth and speed.

The AD analog digital converter group contains high resolution Σ∆ digital converters

(22 bits) and memory components for data transfer to the microcomputer.

Microcomputer System

Adaptation of Sampling Frequency

The implemented software is processed in the microcomputer system (µC). Essential

functions are:

• Filtering and conditioning of the measured signals,

• Continuous monitoring of the measured quantities

• Monitoring of the pickup conditions for the individual protective functions

• Querying of limit values and time sequences,

• Control of signals for logical functions,

• Decision for trip commands

• Signalling of protection behaviour via LEDs, LCD, relays or serial interfaces

• Storage of indications, fault data and fault values for fault analysis,

• Management of the operating system and its associated functions such as data recording, real-time clock, communication, interfaces, etc.

The frequency of the measured quantities is continuously measured and used for adjusting of the actual sampling frequency. This ensures that the protection and measurement functions produce correct results over a wide frequency range. This ensures measuring accuracy in the frequency range from 11 Hz to 69 Hz.

The sampling frequency adaptation can, however, operate only when at least one a.c. measured quantity is present at one of the analog inputs, with an amplitude of at least 5 % of rated value (“operational condition 1”).

If no suitable measured values are present, or if the frequency is below 11 Hz or above 70 Hz, the device operates in mode “operational condition 0”.

Binary Inputs and Outputs

F r o n t E l em e n ts Optical indicators (LEDs) and a front display panel (LC display) provide information on

7UM61 Manual C53000-G1176-C127-3

Binary inputs and outputs from and to the computer system are routed via the I/O modules (inputs and outputs). The computer system obtains the information from the system (e.g remote resetting) or the external equipment (e.g. blocking commands). Outputs are mainly commands that are issued to the switching devices and messages for remote signalling of events and states.

the function of the device and indicate events, states and measured values. Integrated control and numeric keys in conjunction with the LCD facilitate local interaction with the device. By this means all information on the device such as design and setting parameters, operation and disturbance indications and measured values can be queried, (see also SIPROTEC changed.

System Description /1/), and setting parameters can be

1 Introduction

www . ElectricalPartManuals . com

S e r i a l I n t e r f a c e s A serial operator interface in the front cover is provided for local communication with

a PC, using the operating program DIGSI functions of the device.

A serial service possible using DIGSI devices to the PC or for operation via a modem. The service interface can be also used for connecting a RTD-Box (see chapter 2.32)

All data can be transferred to a central control or monitoring system via the serial system transmission modes to suit the particular application.

A further interface is provided for time synchronization ternal synchronization sources.

Further communication protocols can be implemented via additional communication protocols.

Power Supply The functional units described are supplied by a power supply PS with the necessary

power in the different voltage levels. Voltage dips may occur if the voltage supply system (substation battery) becomes short-circuited. Usually, they are bridged by a capacitor (see also Technical Data).

interface. This interface may be provided with various protocols and physical

interface can likewise make communication via PC with the device

4. This is especially well suited for dedicated connection of the

4. This permits convenient operation of all

of the internal clock through ex-

7UM61 Manual

C53000-G1176-C127-3

1.2 Application Scope

www . ElectricalPartManuals . com

The SIPROTEC® 7UM61 device is a digital multi-function machine protection unit from the 7UM6 Numerical Protection series. It provides all functions necessary for protection of generators and motors. As the scope of functions of the 7UM61 can be customized, it is suited for small, medium-sized and large generators.

The device fulfills the protection requirements for the two typical basic connections:

• Busbar connection

• Unit connection

1.2 Application Scope

Figure 1-2 Typical Connections

The scalable software allows a wide range of applications. Corresponding function packages can be selected for each particular application. For instance, alone with the 7UM61 device, it is possible to provide comprehensive and reliable protection of generators from small to medium capacity (approx. 0.5 - 5 MW).

Additionally, the device forms the basis for the protection of medium to large size generators (backup protection). In combination with the 7UM62 device (a further device of the 7UM6 series), all protection requirements encountered in practice for the smallest to the largest machines can be met. This makes possible a consistent concept for reserve protection capacity.

7UM61 Manual C53000-G1176-C127-3

1 Introduction

www . ElectricalPartManuals . com

The 7UM61 device is usable for further applications such as

• Backup protection, since in addition to overcurrent protection, a large variety of protection functions allow, for example, monitoring of voltage and frequency load.

• Protection of synchronous and asynchronous motors.

• Mains Decoupling Device

Messages and Measured Values; Recording of Event and Fault Data

Communication For communication with external operator, control and storage systems, serial inter-

Operator Interface on the Front Panel

The operating messages provide information about conditions in the power system and the device itself. Measurement quantities and resulting computed values can be displayed locally and communicated via the serial interfaces.

Annunciations of the devices can be presented by LEDs on the front panel (allocatable), processed further externally using output contacts (allocatable), combined with user-definable logic functions and/or output via serial interfaces (see Communication below).

During a generator or network fault (fault in the power system), important events and state changes are stored in a fault annunciation buffer. The instantaneous or rms measured values during the fault are also stored in the device and are subsequently available for fault analysis.

faces are available.

A 9-pin DSUB socket on the front panel is used for local communication with a personal computer. By means of the SIPROTEC and evaluation tasks can be executed via this user modifying configuration parameters and settings, configuring user-specific logic functions, retrieving operational and fault messages and measured values, readout and display of fault recordings, querying of devices statuses and measured values.

operating software DIGSI®, all operational

interface, such as specifying and

Rear Panel Interfaces

Depending on the individual ordering variant, additional interfaces are located on the rear panel of the device. These interfaces allow an extensive communication with other digital operating, control and memory components to be set up:

The service nected to this interface. For this reason, remote operation is possible via PC and the DIGSI

The system control centre. The data cables or fibre optic cables can be used. Several standard protocols are available for data transmission:

• IEC 60 870–5–103

Integration of the devices into the substation automation systems SINAUT and SICAM

• Profibus DP

This protocol of automation technology allows transmission of indications and measured values.

• Modbus ASCII/RTU

This protocol of automation technology allows transmission of indications and measured values.

•DNP 3.0

This protocol of automation technology allows transmission of indications and measured values.

interface can be operated through data lines. Also, a modem can be con-

4 operating software, e.g. to operate several devices from a central PC.

interface is used for central communication between the device and a

can also be done with this profile.

LSA

7UM61 Manual

C53000-G1176-C127-3

1.3 Characteristics

www . ElectricalPartManuals . com

General Features • Powerful 32-bit microprocessor system.

• Complete digital processing of measured values and control, from sampling and digitalization of measured quantities to tripping circuit breakers or other switchgear devices.

• Total electrical separation between the internal processing stages of the device and the external transformer, control and DC supply circuits of the system because of the design of the binary inputs, outputs, and the DC converters.

1.3 Characteristics

Definite Time Overcurrent Protection (I>) with Undervoltage Seal-In

• Simple device operation using the integrated operator and display panel or by means of a connected PC running DIGSI

• Continuous computation and display of measured quantities.

• Storage of fault messages and instantaneous or rms values for fault recording.

• Continuous monitoring of measured values as well as of the hardware and software of the device.

• Communication with central control and memory storage equipment via serial interfaces, optionally via data cable, modem, or optic fibre lines.

• Battery-buffered clock that can be synchronized with an IRIG-B (via satellite) or DCF77 signal, binary input signal, or system interface command.

• Statistics: Recording of the number of trip signals instigated by the device and logging of currents switched off last by the device, as well as accumulated shortcircuit currents of each pole of the circuit breaker.

• Operating Hours Counter: Tracking of operating hours of the equipment under load being protected.

• Commissioning aids such as connection check, field rotation check, status display of all binary inputs and outputs, and test measurement recording.

• 2 definite time stages I> and I>> for the 3 phase currents (I

• Undervoltage seal-in for synchronous machines whose excitation voltage is obtained from the machine terminals;

• Optionally additional directional determination with the high current stage I>>.

, IL2, IL3).

• Blocking capability e.g. for reverse-interlocking bus-bar protection with any stage.

Inverse Time Overcurrent Protection (voltage-controlled)

Thermal Overload Protection

7UM61 Manual C53000-G1176-C127-3

• Selection possible from various characteristics (IEC, ANSI).

• Optionally voltage-controlled or voltage-dependent alteration of current pick-up behaviour during undervoltage;

• Voltage influencing can be blocked by fuse failure monitor or via voltage transformer protective circuit breaker.

• Temperature image of current heat losses (overload protection with full memory capability, single body thermal model).

• Additional adjustable warning levels based on temperature rise and current magnitude.

• Consideration of coolant and ambient temperatures possible.

1 Introduction

www . ElectricalPartManuals . com

Negative Sequence Protection

Underexcitation protection

Reverse Power Protection

Forward Power Supervision

• Precise evaluation of negative sequence component of the three phase currents.

• Alarm stage when a set unbalanced load is exceeded.

• Thermal characteristic with adjustable negative sequence factor and adjustable cooldown time.

• High-speed trip stage for large unbalanced loads (can be used for short-circuit protection).

• Conductance measurement from positive sequence components.

• Multi-step characteristic for steady-state and dynamic stability limits;

• Consideration of excitation voltage (only via binary input).

• Calculation of power from positive sequence components.

• Highly sensitive and precise active power measurement (detection of small motor-

ing powers even with low power factor cos ϕ , angle error compensation).

• Insensitive to power fluctuations.

• Long-time stage and short-time stage (active with closed emergency tripping valve).

• Calculation of power from positive sequence components.

• Supervision of over-power (P>) and/or under-power (P<) of active power output with individually adjustable power limits.

Impedance protection

Undervoltage Protection

Overvoltage Protection

Frequency Protection

Overexcitation Protection

• Optionally high-speed or high-accuracy measurement.

• Overcurrent pickup with undervoltage seal-in (for synchronous machines which take their excitation voltage from the terminals).

• 2 impedance zones, 1 overreach zone (switchable via binary input), 4 time stages.

• Polygonal tripping characteristics;

• Two-stage undervoltage measurement of positive sequence component of voltages.

• Two-stage overvoltage measurement of the highest of the three voltages.

• Optionally with phase-to-phase voltages or phase-to-earth voltages.

• Monitoring on undershooting (f<) and/or overshooting (f>) with 4 frequency limits and delay times that are independently adjustable.

• Insensitive to harmonics and abrupt phase angle changes.

• Settable undervoltage threshold.

• Calculation of the ratio U/f.

• Adjustable warning and tripping stage.

• Standard characteristic or arbitrary trip characteristic for calculation of the thermal stress, selectable.

7UM61 Manual

C53000-G1176-C127-3

1.3 Characteristics

www . ElectricalPartManuals . com

Rate-of-FrequencyChange Protection

Vector Jump • Sensitive phase jump detection to be used for network disconnection.

90% Stator Earth Fault Protection

Sensitive Earth F a u l t P r o t e c t i o n

• Monitors whether the frequency overshoots (df/dt>) and/or undershoots (df/dt<) a set limit value, with 4 individually settable limit values or delay times.

• Variable measuring windows

• Coupling to frequency protection pickup.

• Settable undervoltage threshold.

• Suitable for generators in unit connection and directly connected to busbars.

• Measurement of displacement voltage via the neutral or earthing transformer or by calculation from phase-to-earth voltages.

• Highly sensitive earth current detection, optional with or without directional determination with zero sequence components (I

• Directional characteristic adjustable.

• Determination of the earth-faulted phase.

• Two-stage earth fault current measurement: I

• High sensitivity (adjustable on the secondary side from 2 mA).

• Can be used for stator earth fault or rotor earth fault detection.

, U0).

>> and IEE>.

100% Stator Earth Fault Protection w i t h 3 r d H a r m o n i c

Motor Starting Time Supervision

Restart Inhibit for Motors

Breaker Failure Protection

• Measurement circuit monitoring for minimum current flow when used for rotor earth fault protection.

• Detection of the 3rd harmonic of the voltage at the starpoint or broken delta winding of an earthing transformer.

• In addition to the 90-%-stator earth fault protection there is a protection of the entire stator winding (protective range 100 %).

• Inverse time overcurrent tripping based on an evaluation of the motor starting current

• Inverse time delay with blocked rotor.

• Approximate computation of rotor overtemperature.

• Motor switchon is enabled only a if a restartup limit is undershot.

• Calculation of waiting time until automatic reclosure is enabled.

• Different prolongation of cooldown time constants for standstill/operation period is taken into consideration.

• Possibility for disabling the start inhibit if emergency startup is required.

• By checking the current or evaluation of the breaker auxiliary contacts.

• Initiation of each integrated protection function allocated to the circuit breaker.

• Initiation possible through a binary input from an external protective device.

7UM61 Manual C53000-G1176-C127-3

1 Introduction

www . ElectricalPartManuals . com

Inadvertent Energizing Protection

Threshold Supervisions

Temperature Detection by Thermoboxes

Phase Sequence Inversion

User-Defined Functions

• Damage limitation on inadvertent switching on of a stationary generator by fast opening of the generator switch.

• Instantaneous value acquisition of the phase currents.

• Operational state and voltage supervision as well as fuse failure monitor are the enable criteria.

• 6 freely assignable indications for threshold supervision.

• Implementation of fast supervision tasks with CFC.

• Acquisition of any ambient temperatures or coolant temperatures using thermoboxes and external temperature sensors.

• Selectable L1, L2, L3 or L1, L3, L2 via setting (static) or binary input (dynamic).

• Internal and external signals can be logically combined to establish user-defined logic functions.

• All common logic functions (AND, OR, NOT, Exclusive OR, etc.).

• Time delays and limit value interrogations.

• Processing of measured values, including zero suppression, adding a knee characteristic for a transducer input, and live-zero monitoring.

Breaker Control • Circuit breakers can be opened and closed manually via programmable function

Measured Values Monitoring

keys, via the system interface (e.g. by SICAM face (using a PC with DIGSI

• Feedback information on circuit breakers states via the breaker auxiliary contacts.

• Plausibility monitoring of the circuit breaker positions and interlocking conditions for switching.

• Increased reliability thanks to monitoring of internal measuring circuits, of auxiliary power supply, and of hardware and software.

• Current transformer and voltage transformer secondary circuits are monitored using symmetry checks.

• Trip circuit monitoring possible via external circuitry.

• Phase sequence check.

■

or LSA), or via the operating inter-

7UM61 Manual

C53000-G1176-C127-3

Functions 2

www . ElectricalPartManuals . com

This chapter describes the numerous functions available on the SIPROTEC® 4 7UM61. It shows the setting possibilities for all the functions in maximum configuration. Instructions for deriving setting values and formulae, where required are provided.

Additionally it may be defined which functions are to be used.

2.1 Introduction, Reference Systems 29

2.2 Functional Scope 31

2.3 Power System Data 1 34

2.4 Change Group 39

2.5 Power System Data 2 40

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In 42

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection 46

2.8 Inverse-Time Overcurrent Protection (ANSI 51V) 52

2.9 Thermal Overload Protection (ANSI 49) 59

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46) 70

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40) 77

2.12 Reverse Power Protection (ANSI 32R) 85

2.13 Forward Active Power Supervision (ANSI 32F) 89

2.14 Impedance Protection (ANSI 21) 92

2.15 Undervoltage Protection (ANSI 27) 103

2.16 Overvoltage Protection (ANSI 59) 106

2.17 Frequency Protection (ANSI 81) 109

2.18 Overexcitation (Volt/Hertz) Protection (ANSI 24) 113

2.19 Rate-of-Frequency-Change Protection df/dt (ANSI 81R) 118

2.20 Jump of Voltage Vector 123

2.21 90-%-Stator Earth Fault Protection (ANSI 59N, 64G, 67G) 128

2.22 Sensitive Earth Fault Protection (ANSI 51GN, 64R) 136

C53000-G1176-C127-3

277UM61 Manual

2 Functions

www . ElectricalPartManuals . com

2.23 100-%-Stator Earth Fault Protection with 3rd Harmonics (ANSI 27/59TN 3rd Harm.) 140

2.24 Motor Starting Time Supervision (ANSI 48) 144

2.25 Restart Inhibit for Motors (ANSI 66, 49Rotor) 149

2.26 Breaker Failure Protection (ANSI 50BF) 157

2.27 Inadvertent Energization (ANSI 50, 27) 162

2.28 Measurement Supervision 166

2.29 Trip Circuit Supervision 176

2.30 Threshold supervision 183

2.31 External Trip Functions 189

2.32 RTD-Box 192

2.33 Phase Rotation Reversal 201

2.34 Protection Function Control 203

2.35 Ancillary Functions 208

2.36 Command Processing 221

7UM61 Manual

C53000-G1176-C127-3

2.1 Introduction, Reference Systems

www . ElectricalPartManuals . com

2.1 Introduction, Reference Systems

The following chapters explain the individual protective and additional functions and provide information about the setting values.

2.1.1 Functional Description

Generator The calculation examples are based on two smaller capacity reference power systems

with the two typical basic connections, i.e. the busbar connection and the unit connection (see following figure). All default settings of the relay are adapted accordingly.

Figure 2-1 Reference Systems

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Technical Data of the Reference Power Systems

Generator S

Current transformer: I

Toroidal c.t.: I

Voltage transformer: U

Transformer

Transformer: S

Zero point transformer:

= 5.27 MVA

N, T

= 6.3 kV

N, Gen

ING = 483 A

cos ϕ = 0.8

= 500 A; I

N,prim

= 60 A; I

N,prim

=(6.3/√3) kV U

N, prim

= 5.3 MVA

N, T

UOS = 20 kV

U = 6.3 kV

= 7 %

CT=

= 1 A

N, sec

= 1 A

N, sec

= (100/√3) V

N, sec

/3 = (100/3) V

Resistor divider: 5 : 1

Motor

Motor VN = 6600 V

= 126 A

N, M

Current transformer: I

= 624 A (Starting current)

StartCurr.

= 135 A (Permissible continuous stator cur-

max

= 8.5 s (Starting time at ISTRT)

STRT

= 200 A; I

N,prim

Further technical data are provided within the framework of the functional setting specifications of the individual protective functions.

The calculated setting values are secondary setting values related to the device and can be modified immediately by way of local operation.

For a complete reparametrization the operating program DIGSI In this way, the user can specify primary values in addition to secondary settings. This is done in the 7UM61 as a setting referred to the rated values of the object to be protected (e.g. I

N, G

dent, typical settings of the protective functions can be pre-specified. The data of the individual power system are updated in the Power System Data 1 or Power System Data 2 and conversion to secondary values is done by mouse clicking. All necessary conversion formulas of the individual functions are stored in the operating program.

; U

N, G

rent)

= 1 A

N, sec

4 is recommended.

; S

). This procedure has the advantage that system-indepen-

N, G

7UM61 Manual

C53000-G1176-C127-3

2.2 Functional Scope

www . ElectricalPartManuals . com

The 7UM61 device has numerous protection and supplementary functions. The hardware and firmware provided is designed for this scope of functions. Nevertheless a few restrictions apply to the use of the earth fault current and earth fault voltage inputs UE and IEE respectively. The same input can not be simultaneously fed with different measured values, e.g. for rotor earth fault protection and stator earth fault protection.

In addition the command functions can be matched to the system conditions. Also individual functions can be enabled or disabled during configuration. Functions not needed can be thus be deactivated.

The available protection and supplementary functions can be configured as Enabled or Disabled. For some functions a choice between several alternatives is possible, as described below.

Functions configured as disabled are not processed by the 7UM61. There are no indications, and corresponding settings (functions, limit values) are not displayed during setting.

2.2 Functional Scope

2.2.1 Functional Description

Configuration of the Functional Scope

Configuration settings can be entered using a PC and the software program DIGSI and transferred via the front serial port or the rear service interface. Operation is described in the SIPROTEC

For changing configuration parameters in the device, password no.7 is required (for parameter set). Without the password, the settings may be read, but may not be modified and transferred to the device.

Functional scope and as the case may be possible alternatives are adapted to the power system conditions in the Function Scope dialog box.

Note

Available functions and default settings depend on the ordered device variant (see Appendix for details). Also, not all combinations of protective functions are possible because of certain restrictions imposed by the hardware (see Section 2.2.2).

2.2.2 Setting Notes

System Description /1/.

Special Cases Most settings are self-explanatory. The special cases are described below.

If use of the setting group change function is desired, address 103 Grp Chge OPTION should be set to Enabled. In this case, it is possible to apply two groups of settings for function parameters (refer also to Section 2.4) allowing convenient and fast switch-over between these setting groups. Only one function parameter group may be selected and used if the setting is Disabled.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Parameter 104 FAULT VALUE is used to specify whether the oscillographic fault recording should record Instant. values or RMS values. If RMS values is stored, the available recording time increases by the factor 16.

For the high-current stage I>> of the overcurrent protection, address 113O/C PROT. I>> determines whether Non-Directional or directional is to be operative. By selecting Disabled, this overcurrent stage can be excluded altogether. With inverse time overcurrent protection 114O/C PROT. Ip, depending on the ordered variant, various characteristics are available for selection, in accordance with IEC or ANSI standard. Selecting 'disabled' deconfigures inverse time overcurrent protection.

For earth fault protection, Address 150 S/E/F PROT. presents the options non-

dir. U0, non-dir. U0&I0 and directional, unless the whole function is Disabled. The first option evaluates only the displacement voltage (to be used with

unit connection). The second option evaluates in addition to the displacement voltage, the magnitude of the earth fault current (or the difference between the starpoint current and the total current of a toroidal CT in busbar systems with low-ohmic switchable starpoint resistors). The third option considers as a further criterion the direction of the earth fault current if with machines in busbar connection the magnitudes of displacement voltage and earth fault current alone are not sufficient to distinguish between system earth faults and machine earth faults.

For trip circuit monitoring, address 182 Trip Cir. Sup. is used to specify whether two binary inputs (2 Binary Inputs) or only one (1 Binary Input) should be utilized.

2.2.3 Settings

Addr. Parameter Setting Options Default Setting Comments

103 Grp Chge OPTION Disabled

Enabled

104 FAULT VALUE Disabled

Instant. values RMS values

112 O/C PROT. I> Disabled

Enabled

113 O/C PROT. I>> Disabled

directional Non-Directional

114 O/C PROT. Ip Disabled

with IEC with ANSI

116 Therm.Overload Disabled

Enabled

117 UNBALANCE LOAD Disabled

Enabled

130 UNDEREXCIT. Disabled

Enabled

131 REVERSE POWER Disabled

Enabled

132 FORWARD POWER Disabled

Enabled

133 IMPEDANCE PROT. Disabled

Enabled

Disabled Setting Group Change Option

Instant. values Fault values

Enabled Overcurrent Protection I>

Non-Directional Overcurrent Protection I>>

Disabled Inverse O/C Time Protection

Enabled Thermal Overload Protection

Enabled Unbalance Load (Negative Se-

quence)

Enabled Underexcitation Protection

Enabled Reverse Power Protection

Enabled Forward Power Supervision

Enabled Impedance Protection

7UM61 Manual

C53000-G1176-C127-3

2.2 Functional Scope

www . ElectricalPartManuals . com

Addr. Parameter Setting Options Default Setting Comments

140 UNDERVOLTAGE Disabled

Enabled

141 OVERVOLTAGE Disabled

Enabled

142 FREQUENCY Prot. Disabled

Enabled

143 OVEREXC. PROT. Disabled

Enabled

145 df/dt Protect. Disabled

2 df/dt stages 4 df/dt stages

146 VECTOR JUMP Disabled

Enabled

150 S/E/F PROT. Disabled

non-dir. U0 non-dir. U0&I0 directional

151 O/C PROT. Iee> Disabled

Enabled

152 SEF 3rd HARM. Disabled

Enabled

165 STARTUP MOTOR Disabled

Enabled

166 RESTART INHIBIT Disabled

Enabled

170 BREAKER FAILURE Disabled

Enabled

171 INADVERT. EN. Disabled

Enabled

180 FUSE FAIL MON. Disabled

Enabled

181 M.V. SUPERV Disabled

Enabled

182 Trip Cir. Sup. Disabled

2 Binary Inputs 1 Binary Input

185 THRESHOLD Disabled

Enabled

186 EXT. TRIP 1 Disabled

Enabled

187 EXT. TRIP 2 Disabled

Enabled

188 EXT. TRIP 3 Disabled

Enabled

189 EXT. TRIP 4 Disabled

Enabled

190 RTD-BOX INPUT Disabled

Port C Port D Port E

191 RTD CONNECTION 6 RTD simplex

6 RTD HDX 12 RTD HDX

Enabled Undervoltage Protection

Enabled Overvoltage Protection

Enabled Over / Underfrequency Protection

Enabled Overexcitation Protection (U/f)

2 df/dt stages Rate-of-frequency-change protec-

tion

Enabled Jump of Voltage Vector

non-dir. U0&I0 Stator Earth Fault Protection

Enabled Sensitive Earth Current Protection

Enabled Stator Earth Fault Prot. 3rd Har-

monic

Enabled Motor Starting Time Supervision

Enabled Restart Inhibit for Motors

Enabled Breaker Failure Protection

Enabled Inadvertent Energisation

Enabled Fuse Failure Monitor

Enabled Measured Values Supervision

Disabled Trip Circuit Supervision

Enabled Threshold Supervision

Enabled External Trip Function 1

Enabled External Trip Function 2

Enabled External Trip Function 3

Enabled External Trip Function 4

Disabled External Temperature Input

6 RTD simplex Ext. Temperature Input Connec-

tion Type

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.3 Power System Data 1

The device requires certain network and power system data so that it can be adapted to its intended functions in accordance with application. These include, for instance, rated power system and transformer data, measured quantity polarities and connection, breaker properties etc. There are also certain parameters common to all functions, i.e. not associated with a specific protection, control or monitoring function. Section P.System Data 1 describes these.

2.3.1 Setting Notes

General The Power System Data 1 can be changed via the operator or service interface from

a PC using DIGSI

double-click Settings to display the data available.

Connection of the Current Transformer Set

Nominal Values of the Transformers

In DIGSI

In address 210 CT Starpoint the polarity of the current transformers must be entered, i.e. the location of the CT starpoint. This setting determines the measuring direction of the device (forwards = line direction). The following figure shows the definition even in cases where there are no starpoint CTs.

Figure 2-2 Location of the CT Starpoints

At addresses 211 CT PRIMARY and 212 CT SECONDARY, information is entered regarding the primary and secondary current rating of the current transformers. It is important to ensure that the rated secondary current of the current transformer matches the rated current of the device, otherwise the device will incorrectly calculate primary data.

W0 Correction Angle

A correction of the angle faults of the current and voltage transformers is particularly important with regard to reverse power protection, as in this case a very low active

power is computed from a very high apparent power (for small cos ϕ).

At address 204 CT ANGLE W0 a constant correction angle can be entered for the CT.

The angle fault difference ∆ϕ between the current and voltage transformers is partic-

ularly important in this context. As a correction, the sum of the mean angle errors of the current transformers and voltage transformers is set. The corrective value can be determined during machine commissioning (see Section Mounting and Commissioning).

7UM61 Manual

C53000-G1176-C127-3

2.3 Power System Data 1

www . ElectricalPartManuals . com

Iee Transformation Ratios

Nominal Values of Voltage Transformers

Voltage Connection U

For conversion of the ground current Iee in primary quantities, the device requires the primary/secondary transformation ratio of the transformer. This is set at address 213 FACTOR IEE.

At addresses 221 Unom PRIMARY and 222 Unom SECONDARY, information is entered regarding the primary nominal voltage and secondary nominal voltages (phase-tophase) of the connected voltage transformers.

At address 223 UE CONNECTION the user specifies to the device which type of voltage is connected to the UE input. The device establishes from this information how to process the input signal. The following table shows the interdependencies for each protection function.

Table 2-1 Setting Options for the UE Input and their Impact on the Protection Functions

Setting for UE CONNEC-

TION (Addr. 0223)

not connected Processing of U0 computed

UE connected to any transformer

UE connected to broken delta winding

UE connected to neutral transformer

90% Stator Earth Fault

Protection

value (exactly: √3 U0)

Processing of UE input (e.g. earth fault protection on transformer side)

Processing of UE input Processing of UE input

Stator Earth Fault Protec-

tion with 3rd Harmonic

The 3rd harmonic is determined from the computed U0 voltage (U0 3rd harm > stage only usable).

–

UE Transformation Ratio

For conversion of the displacement voltage UE to primary quantities, the device requires the primary/secondary transformation ratio of the transformer delivering the UE voltage. With the exception of the rotor earth fault protection, the 224 FACTOR UE has an impact on those protection functions which process the UE input directly, as shown in Table 2-1. For this ratio224 FACTOR UE the following generally applies:

In this context, U

is the secondary displacement voltage applied to the device. If a voltage divider

E, sec

is used, its division ratio also influences this factor. The following equation results for the example in Section 2.1, unit transformer connection figure, with the power system data selected there and an 1:5 voltage divider ratio

is the primary voltage (generally phase-ground voltage) and

VT, prim

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Uph/Uen Adaption Factor

Rated System Frequency

The address 225 serves to communicate the adaptation factor between the phase voltage and the displacement voltage to the device. This information is relevant for measured quantity monitoring.

If the voltage transformer set has e-n windings connected to the device (UE input), this must be specified accordingly in address 223 (see above margin heading "UE Input"). Since transformation between voltage transformers usually is as follows:

with connected Uen voltage the Uph/Uen factor (secondary voltage, address 225 Uph

/ Udelta) must be set to 3/√3

formation of the displacement voltage via an interconnected transformer set, the factor must be corrected accordingly.

The nominal frequency of the system is set in Address 270 Rated Frequency. The factory setting of the model variant must only be changed if the device is to be used for a purpose other than intended when ordering.

= √3 = 1.73. For other transformation ratios, i.e. the

Phase Rotation Address 271 PHASE SEQ. is used to change the default phase sequence (L1 L2 L3

for clockwise rotation), if your power system permanently has an anti-clockwise phase sequence (L1 L3 L2). A temporary reversal of rotation is also possible using binary inputs (see Section 2.33).

Figure 2-3 Phase sequences

Operating Mode The 272 SCHEME setting is used for specifying if the generator to be protected is op-

erated in Unit transf. or in Busbar mode. This specification is important for stator earth fault connection and for the inverse O/C time protection with undervoltage consideration, as different voltages are used here, depending on the corresponding operating mode (see "Undervoltage Consideration" in Section 2.8).

7UM61 Manual

C53000-G1176-C127-3

2.3 Power System Data 1

www . ElectricalPartManuals . com

ATEX100 Parameter 274 ATEX100 allows compliance with PTB requirements (special require-

ments in Germany) for thermal replicas. If this parameter is set to YES, all thermal replicas of the 7UM61 are stored on auxiliary power supply failure. As soon as the supply voltage returns, the thermal replicas continue operating with the stored values. If the parameter is set to NO, the calculated overtemperature values of all thermal replicas are reset to zero on auxiliary power supply failure.

Command Duration Address 280 is used to set the minimum time TMin TRIP CMD the tripping contacts

will remain closed. This setting applies to all protective functions that initiate tripping.

Current Flow Monitoring

Address 281 BkrClosed I MIN corresponds to the threshold value of the integrated current flow monitoring feature. This setting is used for the elapsed-time meter and the overload protection. If the set threshold current is exceeded, the circuit breaker is considered closed and the power system is considered to be in operation. In the case of overload protection, this criterion distinguishes between standstill and motion of the machine to be protected.

2.3.2 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer.

Addr. Parameter C Setting Options Default Setting Comments

204 CT ANGLE W0 -5.00 .. 5.00 ° 0.00 ° Correction Angle CT W0

210 CT Starpoint towards machine

towards starpt.

211 CT PRIMARY 10 .. 50000 A 500 A CT Rated Primary Current

212 CT SECONDARY 1A

towards machine CT Starpoint

1A CT Rated Secondary

Current

213 FACTOR IEE 1.0 .. 300.0 60.0 CT Ratio Prim./Sec. Iee

221 Unom PRIMARY 0.10 .. 400.00 kV 6.30 kV Rated Primary Voltage

222 Unom SECONDARY 100 .. 125 V 100 V Rated Secondary Voltage

(Ph-Ph)

223 UE CONNECTION neutr. transf.

broken delta Not connected any VT

224 FACTOR UE 1.0 .. 2500.0 36.4 VT Ratio Prim./Sec. Ue

225A Uph / Udelta 1.00 .. 3.00 1.73 Matching Ratio Ph.-VT to

270 Rated Frequency 50 Hz

60 Hz

271 PHASE SEQ. L1 L2 L3

L1 L3 L2

272 SCHEME Busbar

Unit transf.

7UM61 Manual C53000-G1176-C127-3

neutr. transf. UE Connection

Broken-Delta-VT

50 Hz Rated Frequency

L1 L2 L3 Phase Sequence

Busbar Scheme Configuration

2 Functions

www . ElectricalPartManuals . com

Addr. Parameter C Setting Options Default Setting Comments

273 STAR-POINT low-resist.

high-resist.

high-resist. Earthing of Machine Star-

point

274A ATEX100 YES

276 TEMP. UNIT Celsius

Fahrenheit

280 TMin TRIP CMD 0.01 .. 32.00 sec 0.15 sec Minimum TRIP Command

281 BkrClosed I MIN 1A 0.04 .. 1.00 A 0.04 A Closed Breaker Min.

5A 0.20 .. 5.00 A 0.20 A

NO Storage of th. Replicas w/o

Power Supply

Celsius Unit of temperature mea-

surement

Duration

Current Threshold

2.3.3 Information List

No. Information Type of In-

formation

361 >FAIL:Feeder VT EM >Failure: Feeder VT (MCB tripped)

5002 Operat. Cond. AM Suitable measured quantities present

5145 >Reverse Rot. EM >Reverse Phase Rotation

5147 Rotation L1L2L3 AM Phase Rotation L1L2L3

5148 Rotation L1L3L2 AM Phase Rotation L1L3L2

Comments

7UM61 Manual

C53000-G1176-C127-3

2.4 Change Group

www . ElectricalPartManuals . com

Two independent groups of parameters can be set for the device functions. During operation the user can locally switch between setting groups using the operator panel, binary inputs (if so configured), the operator and service interface per PC, or via the system interface.

A setting group includes the setting values for all functions that have been selected as Enabled during configuration (see Section 2.2). In the 7UM61 device, two independent setting groups (A and B) are available. Whereas setting values may vary, the selected functions of each setting group remain the same.

Where different settings are required for operational reasons, e.g. in pumped storage power stations with a machine operating alternately as a generator and a motor, these settings are made in the setting groups and stored in the device. Depending on the operating mode, the applicable setting group is activated, usually via a binary input.

If multiple setting groups are not required, Group A is the default selection. The rest of this section is not relevant.

2.4 Change Group

2.4.1 Setting Notes

General If the changeover option is desired, on function extent configuration group changeover

must be set to Grp Chge OPTION = Enabled (address 103). When setting the function parameters, you configure first setting group A, then setting group B. How to proceed and how to copy or reset settings groups are described in the SIPROTEC System Description /1/.

How to switch between setting groups externally using binary inputs is described in the Mounting and Commissioning section.

2.4.2 Settings

Addr. Parameter Setting Options Default Setting Comments

302 CHANGE Group A

Group B Binary Input Protocol

Group A Change to Another Setting Group

2.4.3 Information List

No. Information Type of In-

formation

- Group A IE Group A

- Group B IE Group B

7 >Set Group Bit0 EM >Setting Group Select Bit 0

8 >Set Group Bit1 EM >Setting Group Select Bit 1

7UM61 Manual C53000-G1176-C127-3

Comments

2 Functions

www . ElectricalPartManuals . com

2.5 Power System Data 2

The general protection data (P.System Data 2) include settings associated with all functions rather than a specific protection or monitoring function. Parameter settings P.System Data 2 can be switched using the setting group.

2.5.1 Functional Description

Setting Groups In the 7UM61 relay, two independent setting groups (A and B) are possible. Whereas

setting values may vary, the selected functions of each setting group remain the same.

2.5.2 Setting Notes

General To enter these group-specific general protection data (P.System Data 2), select in

the SETTINGS menu theGroup A (Parameter group A), and in it P.System Data

2. The other setting group is accessible under Group B.

Rated Values of the System

Active Power Direction

At addresses 1101 U PRIMARY OP. and 1102 I PRIMARY OP., the primary refer- ence voltage and reference current of the protected motor is entered. These values are important for pickup settings. The allow the device to calculate operational values as percentage values. For example, if a CT ratio of 500/1 is selected and the rated current of the generator is 483 A, a value of 500 A should be entered at address 211 and a value of 483 A under I PRIMARY OP.. 483 amps are now displayed as 100% in the percentage metering display.

Address 1108 ACTIVE POWER is used to specify the active power direction in the normal mode (Generator = output or Motor = input) or to adapt it to the power system conditions without device recabling.

2.5.3 Settings

Addr. Parameter Setting Options Default Setting Comments

1101 U PRIMARY OP. 0.10 .. 400.00 kV 6.30 kV Primary Operating Voltage

1102 I PRIMARY OP. 10 .. 50000 A 483 A Primary Operating Current

1108 ACTIVE POWER Generator

Motor

Generator Measurement of Active Power for

2.5.4 Information List

No. Information Type of In-

formation

501 Relay PICKUP AM Relay PICKUP

511 Relay TRIP AM Relay GENERAL TRIP command

533 IL1: AM Primary fault current IL1

Comments

7UM61 Manual

C53000-G1176-C127-3

2.5 Power System Data 2

www . ElectricalPartManuals . com

No. Information Type of In-

formation

534 IL2: AM Primary fault current IL2

535 IL3: AM Primary fault current IL3

5012 UL1E: AM Voltage UL1E at trip

5013 UL2E: AM Voltage UL2E at trip

5014 UL3E: AM Voltage UL3E at trip

5015 P: AM Active power at trip

5016 Q: AM Reactive power at trip

5017 f: AM Frequency at trip

Comments

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In

The overcurrent protection is used as backup protection for the short-circuit protection of the protected object. It also provides backup protection for downstream network faults which may be not promptly disconnected thus endangering the protected object.

Initially, the currents are numerically filtered so that only the fundamental frequency currents are used for the measurement. This makes the measurement insensitive to transient conditions at the inception of a short-circuit and to asymmetrical short-circuit currents (d.c. component).

In generators where the excitation voltage is taken from the machine terminals, the short-circuit current subsides quickly in the event of adjacent faults (i.e. in the generator or unit transformer region) due to the absence of excitation voltage. Within a few seconds it sinks below the pick-up value of the overcurrent time protection. To avoid pickup dropout, the I> stage monitors the positive-sequence component of the voltages and uses it as an additional criterion for detecting a short-circuit. The undervoltage influencing can be disabled off and made ineffective via binary input.

2.6.1 Functional Description

I> Stage Each phase current is compared individually with the I> common setting value and

signaled separately on overshoot. A trip signal is transmitted to the matrix as soon as the corresponding T I> time delay has expired. On delivery the dropout value is set

to ± 95 % below the pickup value. For special applications, it is also possible to set a

higher value.

Undervoltage SealIn

The I> stage has a (disconnectable) undervoltage stage. This stage maintains the pickup signal for a selectable seal-in time if the value falls below a selectable threshold of the positive-sequence component of the voltages after an overcurrent pickup - even if the value falls again below the overcurrent value. In this way, the expire of the trip time delay and the tripping of the related breakers is also ensured in these cases. If the voltage recovers before the seal-in time has expired or if the undervoltage seal-in is blocked via a binary input, e.g. when the voltage transformer mcb trips or if the machine is tripped, protection drops out immediately.

The seal-in logic operates separate for each phase. The first pickup of a phase overcurrent starts the timer T-SEAL-IN.

The following figure shows the logic diagram of the overcurrent time protection I> with undervoltage protection.

7UM61 Manual

C53000-G1176-C127-3

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In

www . ElectricalPartManuals . com

Figure 2-4 Logic Diagram of the Overcurrent Stage I> with Undervoltage Seal-In

2.6.2 Setting Notes

General Overcurrent protection is only effective and available if address 112 O/C PROT. I>

is set to Enabled during configuration. If the function is not needed it is set to Disabled.

Overcurrent Stage I>

Address 1201 O/C I> is used to switch the definite time-overcurrent stage I> ON and OFF, or to block only the trip command (Block relay). For setting the I> overcurrent

stage it is the maximum anticipated load current which is most relevant. Pickup due to overload should never occur since the protection may trip if short command times are set. For this reason, a setting between 20 % and 30 % over the expected peak load is recommended for generators, and a setting of about 40 % for transformers and motors.

The trip time delay (parameter 1203 T I>) must be coordinated with the time grading of the network in order to ensure that the protective equipment closest to the corresponding fault location trips first (selectivity).

The selected time is only an additional time delay and does not include the operating

time (measuring time, dropout time). The delay can be set to ∞. After pickup the

element will then not trip. Pickup, however, will be signaled. If the I> stage is not required at all, address 1201 O/C I> is set to OFF. This prevents tripping and the generation of a pickup message.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Undervoltage Seal-InThe 1205 U< undervoltage stage (positive-sequence voltage) is set to a value below

the lowest phase-to-phase voltage admissible during operation, e.g. 80 V.

The seal-in time 1206 T-SEAL-IN limits the pickup seal-in introduced by the overcurrent/undervoltage. It must be set to a value higher than the T I> time delay.

The dropout ratio r = I

of the overcurrent pickup I> is specified at address 1207

off/Ion

I> DOUT RATIO. The recommended value is r = 0.95. For special applications, e.g. overload warning, it can be set to a higher value (0.98).

Examples:

Pick-up threshold

Trip Time Delay 3 sec

Undervoltage Seal-In

Holding time of U<4 sec

Dropout Ratio 0.95

Rated current IN, Mach

Rated current IN, CT, prim

Rated current IN, sec

1.4 · I

N Mach.

0.8 · I

N Mach.

483 A Rated voltage

N, Mach

500 A Rated voltage U

VT. prim

1 A Rated voltage

N, sec

6.3 kV

100 V

The following secondary setting values result from this specification:

2.6.3 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer.

Addr. Parameter C Setting Options Default Setting Comments

1201 O/C I> OFF

ON Block relay

1202 I> 1A 0.05 .. 20.00 A 1.35 A I> Pickup

5A 0.25 .. 100.00 A 6.75 A

1203 T I> 0.00 .. 60.00 sec; ∞ 3.00 sec T I> Time Delay

OFF Overcurrent Time Protec-

tion I>

7UM61 Manual

C53000-G1176-C127-3

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In

www . ElectricalPartManuals . com

Addr. Parameter C Setting Options Default Setting Comments

1204 U< SEAL-IN ON

OFF

1205 U< 10.0 .. 125.0 V 80.0 V Undervoltage Seal-in

1206 T-SEAL-IN 0.10 .. 60.00 sec 4.00 sec Duration of Undervoltage

1207A I> DOUT RATIO 0.90 .. 0.99 0.95 I> Drop Out Ratio

OFF State of Undervoltage

Seal-in

Pickup

Seal-in

2.6.4 Information List

No. Information Type of In-

formation

1722 >BLOCK I> EM >BLOCK I>

1811 I> Fault L1 AM O/C fault detection stage I> phase L1

1812 I> Fault L2 AM O/C fault detection stage I> phase L2

1813 I> Fault L3 AM O/C fault detection stage I> phase L3

1815 I> TRIP AM O/C I> TRIP

1950 >Useal-in BLK EM >O/C prot. : BLOCK undervoltage seal-in

1965 I> OFF AM O/C prot. stage I> is switched OFF

1966 I> BLOCKED AM O/C prot. stage I> is BLOCKED

1967 I> ACTIVE AM O/C prot. stage I> is ACTIVE

1970 U< seal in AM O/C prot. undervoltage seal-in

Comments

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection

The overcurrent protection is used as backup protection for the short-circuit protection of the protected object. It also provides backup protection for downstream network faults which may be not promp tly disconnected thus endangering t he protected object.

In order to ensure that pick-up always occurs even with internal faults, the protection

- for generators - is usually connected to the current transformer set in the neutral leads of the machine. If this is not the case for an individual power system, the I>> stage can be combined with a short-circuit direction acquisition and switch off a generator short circuit by undelayed tripping without comprising selectivity.

Initially the currents are numerically filtered so that only the fundamental frequency currents are used for the measurement. This makes the measurement insensitive to transient conditions at the inception of a short-circuit and to asymmetrical short-circuit currents (d.c. component).

2.7.1 Function Description

I>> Stage Each phase current is compared individually with the I>> common pick-up value and

signaled on overshoot. A trip signal is transmitted to the matrix as soon as the corre-

sponding T I>> time delays have expired. The dropout value is ± 95 % below the

pick-up value.

Direction Detection The I>> stage is equipped with a (disconnectable) direction element permitting a trip-

ping only for faults in backward (i.e. machine) direction.

For this reason, this stage can be used particularly in applications where no current transformers exist in the generator starpoint and undelayed tripping is nevertheless required on generator faults.

Figure 2-5 Selectivity via Short-Circuit Direction Detection

The direction is detected phase-selectively by means of a cross-polarized voltage. The phase-to-phase voltage normally perpendicular to the fault current vector is used as unfaulted voltage (Figure 2-6). This is considered during the calculation of the di-

rection vector in the clockwise rotating phase sequence by a +90° rotation, and in the anti-clockwise rotating phase by a -90° rotation. For phase-to-phase faults, the posi-

tion of the directional limit lines may change in relation to the collapse of the fault voltage.

7UM61 Manual

C53000-G1176-C127-3

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection

www . ElectricalPartManuals . com

Figure 2-6 Cross-Polarized Voltages for Direction Determination

The phase carrying the highest voltage is selected for the direction decision. With equal current levels, the phase with the smaller number is chosen (I

). The following table shows the allocation of measured values for various types of

before IL2 before

short-circuit faults.

Table 2-2 Allocation of Measured Values for the Determination Direction

Pickup Selected Current Associated Voltage

L1 I

L2 I

L3 I

L1, L2 with IL1>I

L1, L2 with IL1=I

L1, L2 with IL1<I

L2, L3 with IL2>I

L2, L3 with IL2=I

L2, L3 with IL2<I

L3, L1 with IL3>I

L3, L1 with IL3=I

L3, L1 with IL3<I

L1, L2, L3 with IL1>(IL2, IL3)I

L1, L2, L3 with IL2>(IL1, IL3)I

UL3 — U

UL2 — U

UL3 — U

UL2 — U

UL3 — U

If the phase-to-phase voltage used for the direction decision is below the minimum value of approx. 7 V, the voltage is taken from a voltage memory. This voltage also allows unambiguous direction determination if the short-circuit voltage has collapsed (short circuit close to generator terminals). After the expiration of the storage time period (2 cycles), the detected direction is saved, as long as no sufficient measuring voltage is available. If a short circuit already exists at generator startup (or for motors or transformers on connection), so that no voltage is present in the memory and no direction can be determined, a trip is issued.

The direction detection can be disabled via binary input.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-7 Logic Diagram of I>> Stage with Direction Element

2.7.2 Setting Notes

General The high current stage I>> of the time overcurrent protection will only be effective and

available if address 113 O/C PROT. I>> is set to either directional or NonDirectional on configuration. If the function is not needed it is set to Disabled.

If direction acquisition is used, make sure that the CT and VT sets are consistent.

High-current Stage I>>

Address 1301 O/C I>> is used to switch the definite time I>> stage for phase currents ON and OFF, or to block only the trip command (Block relay). The high-current stage I>> (Parameter 1302 and its associated delay time T I>>, 1303) is used for current grading with large impedances existing for example with transformers, motors or generators. It is set in a way ensuring that it picks up for faults up to this impedance.

7UM61 Manual

C53000-G1176-C127-3

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection

www . ElectricalPartManuals . com

Current Transformer in the Starpoint (without direction detection)

Example: Unit Connection

Rated apparent power - generator S

Rated voltage - generator U

Direct-axis transient reactance x’

Transient synchronous generated voltage (salient-pole generator)

Rated apparent power - transformer S

Rated voltage, on the generator side U

Transformer impedance u

Current transformer I

a) Short-circuit calculation

Three-pole short circuit

N, Mach

= 29 %

U’

= 1.2 · U

= 5.3 MVA

N, T

N, VT prim

= 7 %

N, CT, prim

= 1 A

N, sec

= 5.27 MVA

= 6.3 kV

N,Mach

= 6.3 kV

= 500 A

Current Transformer on the Output Side (with direction detection)

b) Setting value:

The setting value is achieved by means of a conversion on the secondary side. In order to exclude an unwanted operation caused by overvoltages or transient phenomena, an additional safety factor of about 1.2 to 1.3 is recommended.

A value of T I>> = 0.1 s is recommended as tripping time delay, in order to enable preferred tripping of the differential protection.

If at Address 113 O/C PROT. I>> was configured as directional, the Addresses 1304 Phase Direction and 1305 LINE ANGLE are accessible. The inclination of the direction straight line representing the separating line between the tripping and the blocking zone can be adapted to the network conditions by way of the LINE ANGLE parameter. To do this, the line angle of the network is set. The direction straight line is perpendicular to the set direction angle. Together with the parameter 1304 Phase Direction = Forward or Reverse, this parameter covers the entire impedance level. This is the reverse direction, provided that the protective relay has been con- nected correctly according to one of the diagrams in the Appendix. A small zone is located between the forward and the reverse zone. Due to phase displacement angles of the transformers, a proper direction decision is not possible. There is no tripping in the configured preferential direction in this zone.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-8 Definition of Parameters 1304 Phase Direction and 1305 LINE ANGLE

Application Example: Motor Protection

The setting value of the direction straight line results from the short-circuit angle of the

feeding network. As a rule, it will be 60°. The current pickup value results from the

short-circuit current calculation. Workable pickup values are situated at about (1.5 to

2) · I ancing procedures are finished.

For motors that have no no separate current transformer in the starpoint, the following figure shows how to use the I>> stage as "differential protection". The configuration of the protection function depends on the transformers. Since this application is most likely to be used for replacements in an existing system, the settings of that system should be the basis for this.

. A short tripping delay (TI>> ≈ 0.05 s to 0.1 s) is required to ensure that bal-

N, G

Figure 2-9 I>> Stage as "Differential Protection"

7UM61 Manual

C53000-G1176-C127-3

2.7 Definite-Time Overcurrent Protection (I>>, ANSI 50, 51, 67) with Direction Detection

www . ElectricalPartManuals . com

2.7.3 Settings

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer.

Addr. Parameter C Setting Options Default Setting Comments

1301 O/C I>> OFF

ON Block relay

1302 I>> 1A 0.05 .. 20.00 A 4.30 A I>> Pickup

5A 0.25 .. 100.00 A 21.50 A

1303 T I>> 0.00 .. 60.00 sec; ∞ 0.10 sec T I>> Time Delay

1304 Phase Direction Forward

Reverse

1305 LINE ANGLE -90 .. 90 ° 60 ° Line Angle

OFF Overcurrent Time Protec-

tion I>>

Reverse Phase Direction

2.7.4 Information List

No. Information Type of In-

formation

1720 >BLOCK dir. EM >BLOCK direction I>> stage

1721 >BLOCK I>> EM >BLOCK I>>

1801 I>> Fault L1 AM O/C fault detection stage I>> phase L1

1802 I>> Fault L2 AM O/C fault detection stage I>> phase L2

1803 I>> Fault L3 AM O/C fault detection stage I>> phase L3

1806 I>> forward AM O/C I>> direction forward

1807 I>> backward AM O/C I>> direction backward

1808 I>> picked up AM O/C prot. I>> picked up

1809 I>> TRIP AM O/C I>> TRIP

1955 I>> OFF AM O/C prot. stage I>> is switched OFF

1956 I>> BLOCKED AM O/C prot. stage I>> is BLOCKED

1957 I>> ACTIVE AM O/C prot. stage I>> is ACTIVE

Comments

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.8 Inverse-Time Overcurrent Protection (ANSI 51V)

The overcurrent time protection replicates the short-circuit protection for small or lowvoltage machines. For larger machines it is used as back-up protection for the machine short-circuit protection (differential protection and/or impedance protection). It provides back-up protection for network faults which may be not promptly disconnected thus endangering the machine.

In generators where the excitation voltage is taken from the machine terminals, the short-circuit current subsides quickly in the event of adjacent faults (i.e. in the generator or unit transformer region) due to the absence of excitation voltage. Within a few seconds it sinks below the pick-up value of the overcurrent time protection. In order to avoid a dropout of the pickup, the positive-sequence component is monitored additionally. This component can influence the overcurrent detection in accordance with two different methods. Undervoltage influencing can be disabled.

The protective function operates, depending on the ordering variant, with an inverse current-tripping characteristic according to the IEC or ANSI standards. The characteristics and associated formulas are given in the Technical Data. During configuration of the inverse time curves, the independent stages I>> and I> are enabled (see Section

2.6).

2.8.1 Functional Description

Pickup and Tripping

Dropout The dropout of a picked up stage is performed as soon as the value falls below ap-

Undervoltage Consideration

Each phase current is compared individually with the common Ip setting value. If the current exceeds 1.1 times the setting value, the stage picks up and is signaled phaserelated. For pickup the rms values of the fundamental harmonic are used. During the pickup of an Ip stage, the tripping time is calculated from the flowing fault current using an integrating measuring procedure, depending on the selected tripping characteristic. After the end of this period a trip command is transmitted.

proximately 95 % of the pickup value (i.e. 0.95 to 1.1 = 1.045 to setting value). A renewed pickup will the delay timer to start anew.

The inverse overcurrent time protection is provided with a undervoltage detection that can be disabled. This function can influence overcurrent detection in two different ways:

• Voltage controlled: If the value falls below a settable voltage threshold, an over-

current stage with a lower pick-up value is enabled.

• voltage restraint: The pickup threshold of the overcurrent stage depends on the

voltage level. A lower voltage reduces the current pickup value (see the following figure). A linear, directly proportional dependency is used in the zone between U/U

= 1.00 and 0.25. Consequently, the following applies:

Nom

7UM61 Manual

C53000-G1176-C127-3

Figure 2-10 Pick-up Value Voltage Dependency

www . ElectricalPartManuals . com

2.8 Inverse-Time Overcurrent Protection (ANSI 51V)

The Ip reference value is decreased proportional to voltage decrease. Consequently for constant current I, the I/Ip ratio is increased and the trip time is reduced. Compared with the standard characteristics represented in Section 4 the tripping characteristic shifts to the left side in relation to decreasing voltage.

The changeover to the lower pick-up value or the reduction of the pickup threshold are performed on a per phase basis. Allocations of voltages to the current-carrying phases represented in the following table apply. As the protection used in the generator range is incorporated in the network grading plan, conversion of the voltages by the unit transformer must also be considered. Therefore in principle a distinction must be made between a unit connection and a busbar connection which must be communicated to the device by the parameter 272 SCHEME. As phase-to-phase voltages are referred to in any case, faulty measurements during earth faults are avoided.

Table 2-3 Controlling voltages in relation to the fault currents

Current Voltage

Busbar connection Unit connection

UL1 – U

UL2 – U

UL3 – U

((UL1 – UL2) – (UL3 – U

((UL2 – UL3) – (UL1 – U

((UL3 – UL1) – (UL2 – U

)) / √3

In or to avoid unwanted operation during a voltage transformer fault, a function blocking is implemented via a binary input controlled by the voltage transformer protective breaker as well as via the device-internal measuring voltages failure detection (“Fuse– Failure–Monitor”, also refer to Section 2.28).

The following figure shows the logic diagram of the inverse overcurrent time protection without undervoltage influencing, whereas Figures 2-12 and 2-13 illustrate the logic diagrams with undervoltage influencing.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-11 Logic Diagram of the Inverse Overcurrent Time Protection without Undervoltage Influencing

7UM61 Manual

C53000-G1176-C127-3

2.8 Inverse-Time Overcurrent Protection (ANSI 51V)

www . ElectricalPartManuals . com

Figure 2-12 Logic Diagram of the Voltage Controlled Inverse Overcurrent Time Protection

The changeover to the lower current pickup value on decreasing voltage (loop enable) is performed on a phase by phase basis in accordance with Table 2-3.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-13 Logic Diagram of the Voltage Restraint Inverse Time Overcurrent Protection

The reduction of the current pickup threshold on decreasing voltage (control voltage allocation) is performed phase in accordance with Table 2-3.

2.8.2 Setting Notes

General Inverse overcurrent time protection is only effective and available if address 114 O/C

PROT. Ip was set to with IEC or with ANSI. If the function is not needed it is set to Disabled.

Ip Overcurrent Stage

The address 1401 O/C Ip serves to switch the function ON or OFF or to block only the trip command (Block relay). It must be noted that, for the inverse overcurrent time protection, a safety factor of about 1.1 has been included between the pick-up value and the setting value. This means that a pickup will only occur if a current of about 1.1 times of the setting value is present. The dropout occurs as soon as the value falls below 95% of the pickup value.

7UM61 Manual

C53000-G1176-C127-3

2.8 Inverse-Time Overcurrent Protection (ANSI 51V)

www . ElectricalPartManuals . com

The current value is set at address 1402 Ip. The setting is mainly determined by the maximum operating current. Pickup due to overload should never occur, since the device in this operating mode operates as fault protection with correspondingly short tripping times and not as overload protection.

The corresponding time multiplier for configuration of IEC characteristics (address 114 O/C PROT. Ip = with IEC) is accessible under address 1403 T Ip.

The corresponding time multiplier for configuration of ANSI characteristics (address

114 O/C PROT. Ip= with ANSI) is accessible under address 1404 TIME DIAL: TD.

The time multipliers must be coordinated with the network grading plan.

The time multipliers can also be set to ∞. After pickup the element will then not trip.

Pickup, however, will be signaled. If the Ip stage is not required, on configuration of the protection function (Section 2.2) address 114 O/C PROT. Ip is set to Disabled or this function switched under 1401 O/C Ip = OFF.

The address 1408 serves to predefine the U< pick-up value for the undervoltage trip of the Ip pickup value for voltage-controlled inverse overcurrent time protection/AMZ (parameter 1407 VOLT. INFLUENCE = Volt. controll.). The parameter is set to a value just below the lowest phase-to-phase voltage admissible during operation, e.g. from 75 to 80 V. In this context, the same rules apply as for the undervoltage sealin of the definite overcurrent time protection (see also subsection 2.6.2).

If at address 1407 VOLT. INFLUENCE is set to without or Volt. restraint, the parameter 1408 has no function.

2.8.3 Settings

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer.

Addr. Parameter C Setting Options Default Setting Comments

1401 O/C Ip OFF

ON Block relay

1402 Ip 1A 0.10 .. 4.00 A 1.00 A Ip Pickup

5A 0.50 .. 20.00 A 5.00 A

1403 T Ip 0.05 .. 3.20 sec; ∞ 0.50 sec T Ip Time Dial 1404 TIME DIAL: TD 0.50 .. 15.00 ; ∞ 5.00 TIME DIAL: TD

1405 IEC CURVE Normal Inverse

Very Inverse Extremely Inv.

1406 ANSI CURVE Very Inverse

Inverse Moderately Inv. Extremely Inv. Definite Inv.

OFF Inverse O/C Time Protec-

tion Ip

Normal Inverse IEC Curve

Very Inverse ANSI Curve

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Addr. Parameter C Setting Options Default Setting Comments

1407 VOLT. INFLUENCE without

Volt. controll. Volt. restraint

1408 U< 10.0 .. 125.0 V 75.0 V U< Threshold for Release

without Voltage Influence

2.8.4 Information List

No. Information Type of In-

formation

1883 >BLOCK O/C Ip EM >BLOCK inverse O/C time protection

1891 O/C Ip OFF AM O/C protection Ip is switched OFF

1892 O/C Ip BLOCKED AM O/C protection Ip is BLOCKED

1893 O/C Ip ACTIVE AM O/C protection Ip is ACTIVE

1896 O/C Ip Fault L1 AM O/C fault detection Ip phase L1

1897 O/C Ip Fault L2 AM O/C fault detection Ip phase L2

1898 O/C Ip Fault L3 AM O/C fault detection Ip phase L3

1899 O/C Ip pick.up AM O/C Ip picked up

1900 O/C Ip TRIP AM O/C Ip TRIP

Comments

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

2.9 Thermal Overload Protection (ANSI 49)

The thermal overload protection prevents thermal overloading of the stator windings of the machine being protected.

2.9.1 Functional Description

Thermal Profile The device calculates the excessive temperatures in accordance with a single-body

thermal model, based on the following differential equation:

with

Θ – Current overtemperature as a percent of final overtemperature at

the maximum admissible phase current k · I

– Coolant temperature as a difference to the 40 °C reference temper-

ature

τ – Thermal time constant for heatup of the equipment being protected

I – Current rms phase current as a percentage of maximum admissible

phase current I

The protection function models a thermal profile of the equipment being protected (overload protection with memory capability). Both the previous history of an overload and the heat loss to the environment are taken into account.

The solution of this equation is in steady-state operation an exponential function

whose asymptote represents the final temperature Θ

temperature threshold´is reached, an alarm is issued for e.g. load reduction measures. If the second overtemperature threshold, i.e. final overtemperature = trip temperature, is reached, the protected equipment is disconnected from the network. It is also possible, however, to set the overload protection to Alarm Only . In this case only an indication is issued when the final temperature is reached.

The overtemperature is calculated from the largest of the three phase currents. Since the calculation is based on rms values of currents, harmonics which contribute to a temperature rise of the stator winding are also considered.

The maximum thermally admissible continuous current I of the nominal current I

= k · I

max

Apart from the k factor (parameter K-FACTOR) the TIME CONSTANT τ and the alarm temperature Θ ALARM (as a percentage of the trip temperature Θ

tered.

max

= k · I

. After an initial settable over-

End

is described as a multiple

max

) are to be en-

TRIP

Overload protection also has a current alarm feature (I ALARM) in addition to the temperature alarm stage. This may report an overload current prematurely (before I exceeded), even if the overtemperature has not yet attained the alarm or tripping levels.

7UM61 Manual C53000-G1176-C127-3

max

2 Functions

www . ElectricalPartManuals . com

Coolant Temperature (Ambient Temperature)

C u r r e n t L i m i t i n g In order that overload protection on occurrence of high fault currents (and with small

With 7UM61 the thermal model of the considers an external temperature value. Depending on the application, this temperature can be the coolant or ambient temperature or, in the case of gas turbines, the entry temperature of the cold gas.

The temperature to be considered can be input in one of the following ways:

• via Profibus DP interface/Modbus

• Via temperature detection unit (Thermobox, RTD 1)

The ambient or coolant temperature can also be detected by an external temperature sensor, digitized and fed to the 7UM61 via the Profibus-DP Interface / Modbus .

If a temperature supervision feature is implemented using a thermobox (see Section

2.32) the RTD1 input can be used for temperature inclusion in the overload protection.

With coolant temperature detection in accordance with one of the three methods described, the maximum permissible current I ence of the coolant. If the ambient or coolant temperature is lower, the machine can support a higher current than when the temperatures are high.

time constants) does not cause extremely short trip times thereby perhaps affecting time grading of the fault protection, it is possible to implement current limiting for the overload protection. Currents exceeding the value specified at parameter 1615 I MAX THERM. are limited to this value. For this reason, they do not further reduce trip time in the thermal memory.

is influenced by the temperature differ-

max

Standstill Time Constant

Blocking The thermal memory may be reset via a binary input (“>RM th.rep. O/L”). The

The above differential equation assumes a constant cooling that is reflected by the

time constant τ = R

tilated machine, however, the thermal time constant at standstill can differ considerably from the time constant of a continually running machine, since then the ventilation provides for cooling whereas at standstill only natural convection takes place.

Therefore, two time constants must be considered in such cases for setting.

In this context, machine standstill is detected when the current undershoots the threshold value BkrClosed I MIN (see margin heading "Current Flow Monitoring" in Section 2.3).

current-induced excessive temperature value is reset to zero. The same is achieved by entering a blocking (“>BLK ThOverload”); in that case the overload protection is blocked completely, including the current alarm stage.

When machines must be started for emergency reasons, operating temperatures above the maximum permissible overtemperatures can be allowed by blocking the tripping signal via a binary input (“>Emer.Start O/L”). Since the thermal profile may have exceeded the tripping temperature after startup and dropout of the binary input has taken place, the protection function features a programmable run-on time interval (T EMERGENCY) which is started when the binary input drops out and continues suppressing a trip signal. Tripping will be suppressed until this time interval elapses. This binary input affects only the tripping signal. It has no effect on the fault condition logging nor does it reset the thermal profile.

· Cth (thermal resistance and thermal capacitance). In a self-ven-

Behaviour in Case of Power Supply Failure

For overload protection, together with all other thermal protection functions of the 7UM61 in the Power System Data 1 (parameter 274 ATEX100, see Section 2.3) it is possible to choose whether the calculated overtemperature will be stored throughout a power supply failure, or reset to zero. This last option is the default setting.

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

The following figure shows the logic diagram for overload protection.

Figure 2-14 Logic Diagram of the Overload Protection

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.9.2 Setting Notes

General Overload protection is only effective and accessible if address 116 Therm.Overload

is set to Enabled during configuration. If the function is not required Disabled is set.

Transformers and generators are prone to damage by extended overloads. These overloads cannot and should not be detected by short-circuit protection. Time overcurrent protection should be set high so that it only detects faults, since short-circuit protection only permits short time delays. Short time delays, however, do not allow measures for unburdening the overloaded equipment nor do they permit advantage to be taken of its (limited) overload capacity.

The 7UM61 protective relay features an overload protective function with thermal tripping characteristic adaptable to the overload capability of the equipment being protected.

At address 1601 Ther. OVER LOAD the thermal overload protection ON or OFF can be set, the trip command blocked (Block relay) or the protection function set toAlarm Only. In the latter case no fault record is created should an overload occur. If overload protection is switched ON, tripping is also possible.

K Factor The overload protection is set with quantities per unit. The nominal current I

of the object to be protected (generator, motor, transformer) is typically used as base current. The thermally admissible continuous current I a factor k

The thermally admissible continuous current for the equipment being protected is generally obtainable from manufacturers specifications. If no specifications are available, a value of 1.1 times the nominal current rating is assumed.

The K-FACTOR (address1602) to be set on the device 7UM61 refers to the secondary nominal current (= device current). The following applies for the conversion:

prim

can be used to calculate

max prim

N, machine

with

Thermally admissible continuous motor primary current

max prim

N Machine

N CT prim

Nominal primary CT current

Nominal Current of the Machine

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

Example: Generator and current transformer with the following data:

Permissible Continuous Current I

Generator Nominal Current I

Current Transformer 500 A / 1 A

Time Constant τ Overload protection tracks overtemperature progression, employing a thermal differ-

ential equation whose steady state solution is an exponential function. The TIME

CONSTANT τ (address 1603) is used in the calculation to determine the threshold of

excessive temperature and thus, the tripping temperature.

If the overload characteristic of the generator to be protected is pre-determined, the user must select the protection trip characteristic so that it largely corresponds the overload characteristic, at least for small overloads.

This is also the case if the admissible power-up time corresponding to a certain overload value is indicated.

Alarm Stages By setting the thermal alarm level Θ ALARM (address 1604), a alarm message can be

issued before the tripping temperature is reached, thus avoiding tripping by promptly reducing load. This alarm level simultaneously represents the dropout level for the tripping signal. The tripping signal is interrupted only when this threshold value is again undershot.

N Machine

max prim

= 483 A

= 1.15 · I

N, Machine

The thermal alarm level is given in % of the tripping overtemperature level.

Note: With the typical value of K-FACTOR = 1.1, on application of nominal machine current and adapted primary transformer current, the following final tripping overtemperature results

of the tripping temperature. Consequently, the alarm stage should be set between the final overtemperature with the nominal current (in this case 83 %) and the tripping overtemperature (100 %).

In the present example, the thermal memory reaches the following value if the nominal current is applied:

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

A current-related alarm level is also available (address 1610 I ALARM). The level is set in secondary amperes and should be set equal to, or slightly less than, the permissible continuous current K-FACTOR · I level by setting the thermal alarm level to 100 % and is then practically inactive.

. It may be used instead of the thermal alarm

N sec

Extension of Time Constants at Machine Standstill

Current Limiting The parameter 1615 I MAX THERM. specifies up to which current value the trip times

The time constant programmed at address 1603 is valid for the running machine. On slowing down or standstill, the machine may cool down much more slowly. This be-

haviour can be modeled by prolonging the time constant by the Kτ-FACTOR (address

1612) on machine standstill. In this context, machine standstill is detected when the current falls below the threshold value BkrClosed I MIN (see margin heading "Current Flow Monitoring" in section P.System Data 1).

If no distinction between time constants is necessary, the prolongation factor Kτ-

FACTOR can be left as 1.0 (default).

are calculated in accordance with the prescribed formula. In the trip characteristics of the following figure, this limit value determines the transition to the horizontal part of the characteristics, where there is no further trip time reduction for increasing current values. The limit value must ensure that even for the highest possible short-circuit current, the trip times of the overload protection exceed the trip times of the short-circuit protection devices (differential protection, impedance protection, time overcurrent protection). As a rule, a limitation to a secondary current corresponding to roughly three times the nominal machine current will be sufficient.

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

Figure 2-15 Tripping Characteristics for Overload Protection

Emergency Startup The run-on time to be entered at address 1616 T EMERGENCY must be sufficient to

ensure that after an emergency startup and dropout of binary input “>Emer.Start O/L” the trip command is blocked until the thermal replica is again below the dropout threshold.

Ambient or Coolant Temperature

7UM61 Manual C53000-G1176-C127-3

The specifications given up to now are sufficient for modeling overtemperature. In addition to this, the machine protection can also process the ambient or coolant temperature. This temperature value must be communicated to the device as digitalized measured value via field bus (e.g. Profibus DP). Address 1607 TEMP. INPUT serves to select the temperature input procedure. If there is no coolant temperature detection,

2 Functions

www . ElectricalPartManuals . com

address 1607 is set to Disabled. The allocation between the input signal and the

temperature can be set at address 1608 (in °C) or 1609 (in °F) TEMP. SCAL.. For

this the temperature value set here corresponds to the 100% value from Profibus DP.

In the default setting, 100% (field bus) correspond to 100°C.

If under address 1607 TEMP. INPUT the temperature setting of RTD 1 selected, the scaling under address1608 or 1609 is ineffective. The works setting can be left as it is.

If the ambient temperature detection is used, the user must be aware that the K-

FACTOR to be set refers to an ambient temperature of 104.00 °F or 40 °C, i.e. it corre- sponds to the maximum permissible current at a temperature of 104.00 °F or 40 °C.

All calculations are performed with standardized quantities. The ambient temperature must also be standardized. The temperature at nominal machine current is used as standardization value. If the nominal machine current deviates from the nominal CT current, the temperature must be adapted according to the following formula. At address 1605 or 1606 TEMP. RISE I the temperature adapted to the nominal transformer current is set. This setting value is used as standardization quantity of the ambient temperature input.

with

Machine Temperature with Secondary Nominal Current = Setting at

Nsec

Machine Temperature with Nominal Machine Current

NMach

Nominal primary CT current

Nprim

Nominal Current of the Machine

NMach

If the temperature input is not used, the address 1607 TEMP. INPUT is to be set to

Disabled . In this case, the settings of the addresses1605 or 1606 and 1608 or 1609 are not considered.

the 7UM61 (address 1605 or 1606)

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

If the temperature input is used, the trip times change if the coolant temperature devi-

ates from the internal reference temperature of 104.00 °F or 40 °C. The following

formula can be used to calculate the trip time:

with

τ TIME CONSTANT (address 1603)

k K-FACTOR (address 1602)

I Actually Flowing Secondary Current

Pre

Temperature with Nominal Current IN(Address 1605)

Coolant Temperature Input (Scaling with Address 1608 or 1609)

Example:

Machine:

NMach

maxMach

Current transformer: 500 A/1 A

Nominal Device Current

Previous Load Current

= 483 A

= 1.15 I

= 600 s (thermal time constant of the machine)

at ΘK = 40 °C

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

With a supposed load current of I = 1.5 · I

ambient temperatures Θ

the following trip times result

N, Device

and a preload I

= 0, for different

pre

2.9.3 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer.

Addr. Parameter C Setting Options Default Setting Comments

1601 Ther. OVER LOAD OFF

ON Block relay Alarm Only

1602 K-FACTOR 0.10 .. 4.00 1.11 K-Factor

1603 TIME CONSTANT 30 .. 32000 sec 600 sec Thermal Time Constant

1604 Θ ALARM 70 .. 100 % 90 % Thermal Alarm Stage 1605 TEMP. RISE I 40 .. 200 °C100°C Temperature Rise at

1606 TEMP. RISE I 104 .. 392 °F212°F Temperature Rise at

1607 TEMP. INPUT Disabled

Fieldbus RTD 1

OFF Thermal Overload Protec-

tion

Rated Sec. Curr.

Disabled Temperature Input

7UM61 Manual

C53000-G1176-C127-3

2.9 Thermal Overload Protection (ANSI 49)

www . ElectricalPartManuals . com

Addr. Parameter C Setting Options Default Setting Comments

1608 TEMP. SCAL. 40 .. 300 °C100°C Temperature for Scaling 1609 TEMP. SCAL. 104 .. 572 °F212°F Temperature for Scaling

1610A I ALARM 1A 0.10 .. 4.00 A 1.00 A Current Overload Alarm

5A 0.50 .. 20.00 A 5.00 A

1612A Kτ-FACTOR 1.0 .. 10.0 1.0 Kt-Factor when Motor

1615A I MAX THERM. 1A 0.50 .. 8.00 A 3.30 A Maximum Current for

5A 2.50 .. 40.00 A 16.50 A

1616A T EMERGENCY 10 .. 15000 sec 100 sec Emergency Time

Setpoint

Stops

Thermal Replica

2.9.4 Information List

No. Information Type of In-

formation

1503 >BLK ThOverload EM >BLOCK thermal overload protection

1506 >RM th.rep. O/L EM >Reset memory for thermal replica O/L

1507 >Emer.Start O/L EM >Emergency start O/L

1508 >Fail.Temp.inp EM >Failure temperature input

1511 Th.Overload OFF AM Thermal Overload Protection OFF

1512 Th.Overload BLK AM Thermal Overload Protection BLOCKED

1513 Overload ACT AM Overload Protection ACTIVE

1514 Fail.Temp.inp AM Failure temperature input

1515 O/L I Alarm AM Overload Current Alarm (I alarm)

1516 O/L Θ Alarm AM Thermal Overload Alarm

1517 O/L Th. pick.up AM Thermal Overload picked up

1519 RM th.rep. O/L AM Reset memory for thermal replica O/L

1521 ThOverload TRIP AM Thermal Overload TRIP

Comments

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46)

Unbalanced load protection detects unbalanced loads of three-phase induction machines. Unbalanced loads create a counter-rotating field which acts on the rotor at double frequency. Eddy currents are induced at the rotor surface leading to local overheating in rotor end zones and slot wedges. Another effect of unbalanced loads is overheating of the damper winding. In addition, this protection function may be used to detect interruptions, short circuits and polarity problems with current transformers. It is also useful in detecting 1-pole and 2-pole faults with magnitudes lower than the load currents.

2.10.1 Functional Description

Unbalanced Load Determination

Warning Stage If the value of the continuously permissible, negative phase-sequence current I2> is

Thermal Characteristic

The unbalanced load protection of 7UM61 filters the fundamental component from the phase currents and splits it into symmetrical components. It evaluates the negativephase sequence system, the negative phase-sequence current I phase-sequence current exceeds a set threshold value, the trip timer starts. A trip command is transmitted on timeout.

exceeded, after expiry of a set time T WARN a warning message “I2> Warn” is issued (see Figure 2-16).

The machine manufacturers indicate the permissible unbalanced load by means of the following formula:

The asymmetry factor depends on the machine and represents the time in seconds during which the generator can be loaded with a 100 % unbalanced load. This factor is typically in a range between 5 s and 30 s.

. If the negative

The heating up of the object to be protected is calculated in the device as soon as the permissible unbalanced load I2> is exceeded. The current-time area is calculated constantly to ensure correct consideration of different load cases. As soon as the current-time-area ((I teristic is tripped.

Limitation To avoid overfunctioning of the thermal tripping stage during asymmetrical short cir-

cuits, the input current I of the I ping time of the thermal function is constant. In addition the thermal memory is limited to 200% of the tripping temperature. This avoids prolonged cooling after a delayed short circuit tripping.

>> stage (Addr. 1701), whichever is smaller. Above this current value the trip-

)2 · t) has reached the K asymmetry factor, the thermal charac-

2/IN

is restricted. This limit is either 10 · I

or the setting value

2adm.

7UM61 Manual

C53000-G1176-C127-3

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46)

www . ElectricalPartManuals . com

Cool Down A settable cool-down time starts as soon as the constantly permissible unbalanced

load I2> is undershot. The tripping drops out on dropout of the pickup threshold dropout. However, the counter content is reset to zero with the cooling time parameterized at address 1705 T COOL DOWN. In this context, this parameter is defined as the time required by the thermal image to cool down from 100 % to 0 %. The cool-down time depends on the construction type of the generator, and especially on the damper winding. Preloading is taken into consideration when unbalanced loading occurs during the cool-down period. The protective relay will thus trip in a shorter time.

Tripping Stages

Figure 2-16 Tripping Zone of the Unbalanced Load Protection

Definite Time Tripping Stage

Logic The following figure shows the logic diagram for the unbalanced load protection. The

High negative phase sequence currents can only be caused by a phase-to-phase short circuit in the system which must be covered in accordance with the network grading plan. For this reason, the thermal characteristic is cut by a selectable, definite time negative phase-sequence current stage (parameters 1706 I2>> and 1707 T I2>>).

Please also observe the instructions regarding phase sequence changeover in Sections 2.3 and 2.33.

protection may be blocked via a binary input (“>BLOCK I2”). Pickups and time stages are reset and the metered values in the thermal model are cleared. The binary input “>RM th.rep. I2” only serves to clear metered values of the thermal characteristic.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-17 Logic diagram of the unbalanced load protection

2.10.2 Setting Notes

General The unbalanced load protection is only in effect and accessible if address 117

UNBALANCE LOAD is set to Enabled during configuration. If the function is not re- quired Disabled is set.

The address 1701 UNBALANCE LOAD serves to switch the unbalanced load protection ON or OFF or to block only the trip command (Block relay).

The maximum permissible, continual negative phase-sequence current is important for the thermal model. For machines of up to 100 MVA with non-salient pole rotors, this typically amounts to a value in a range from 6 % to 8 % of the nominal machine current, and with salient-pole rotors at least 12 %. For larger machines and in cases of doubt, please refer to the instructions of the machine manufacturer.

It is important to note that the manufacturer's data relate to the primary values of the machine, for example, the maximum permissible continuous inverse current is referred to the nominal machine current. For settings on the protective relay, this data is converted to the secondary inverse current. The following applies

with

Permissible thermal inverse current of the motor

Nominal current of the machine

Primary nominal current of the current transformer

7UM61 Manual

C53000-G1176-C127-3

2 perm prim

N Mach

N VT prim

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46)

www . ElectricalPartManuals . com

Pickup Threshold / Warning Stage

Negative Sequence Factor K

Conversion to Secondary Values

The value for I2> is set at Address 1702. It is at the same time the pickup value for a current warning stage whose delay time T WARN is set at address 1703.

Example:

Machine I

Current transform-erI

Setting value I

N Mach

2 perm prim

N CT prim

2 adm.

/ I

N Mach

= 483 A

= 11 % permanent (salient-pole machine, see Figure 2-18)

= 500 A

= 11 % · (483 A/500 A) = 10.6 %

If the machine manufacturer has indicated the loadability duration due to an unbalanced load by means of the constant K = (I

)2 · t, it is set directly at address1704

2/IN

FACTOR K. The constant K is proportional to the admissible energy loss.

The factor K can be derived from the unbalanced load characteristic according to the following figure by reading the time at point I

= 1, corresponding to FACTOR K .

2/IN

Example:

= 20 s for I2/IN = 1

adm

The constant K

= 20 s determined in this way is valid for the machine side (pri-

primary

mary side).

The factor K

can be converted to the secondary side by means of the following

primary

formula:

The calculated asymmetry factor K

Example:

= 483 A

N Mach

N CT prim

Factor K

= 500 A

= 20 s

primary

Setting value at address 1704:

is set as FACTOR K at address 1704.

sec

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-18 Example of an Unbalanced Load Characteristic Specified by the Machine Man-

ufacturer

Cooldown Time The parameter 1705 T COOL DOWN establishes the time required by the protection

object to cool down under admissible unbalanced load I2> to the initial value. If the machine manufacturer does not provide this information, the setting value can be calculated by assuming an equal value for cool-down time and heatup time of the object to be protected. The formula below shows the relation between the K asymmetry factor and the cool-down time:

Example:

The following cool-down time results for a K = 20 s and an admissible continual unbalanced load I

2/IN

= 11 %.

7UM61 Manual

C53000-G1176-C127-3

2.10 Unbalanced Load (Negative Sequence) Protection (ANSI 46)

www . ElectricalPartManuals . com

This value T COOL DOWN is set at address 1705.

Definite-Time Tripping Characteristic

Asymmetrical faults also cause high negative phase-sequence currents. A definitetime negative phase-sequence current stage characteristic 1706 I2>> can thus detect asymmetrical power system short circuits. A setting between 60 % and 65 % ensures trip always occurs in accordance with the thermal characteristic in case of a

phase failure (unbalanced load continually below 100/√3

other hand, a two-pole short circuit can be assumed for an unbalanced load of more between 60 % and 65 %. The delay time T I2>> (address 1707) must be coordinated with the system grading of phase-to-phase short circuits.

Contrary to time-overcurrent protection, the I2>> stage is able to detect fault currents at nominal current. The following conditions apply:

A phase-to-ground fault with current I corresponds to a negative sequence current:

%, i.e. I2 < 58 %). On the

With an isolated starpoint, the I current value is particularly low and can be neglected. With a low-resistance grounding, however, it is determined by the ground resistance.

2.10.3 Settings

Addr. Parameter Setting Options Default Setting Comments

1701 UNBALANCE LOAD OFF

ON Block relay

1702 I2> 3.0 .. 30.0 % 10.6 % Continously Permissible Current

1703 T WARN 0.00 .. 60.00 sec; ∞ 20.00 sec Warning Stage Time Delay 1704 FACTOR K 2.0 .. 100.0 sec; ∞ 18.7 sec Negativ Sequence Factor K

1705 T COOL DOWN 0 .. 50000 sec 1650 sec Time for Cooling Down

7UM61 Manual C53000-G1176-C127-3

OFF Unbalance Load Protection

2 Functions

www . ElectricalPartManuals . com

Addr. Parameter Setting Options Default Setting Comments

1706 I2>> 10 .. 100 % 60 % I2>> Pickup

1707 T I2>> 0.00 .. 60.00 sec; ∞ 3.00 sec T I2>> Time Delay

2.10.4 Information List

No. Information Type of In-

formation

5143 >BLOCK I2 EM >BLOCK I2 (Unbalance Load)

5146 >RM th.rep. I2 EM >Reset memory for thermal replica I2

5151 I2 OFF AM I2 switched OFF

5152 I2 BLOCKED AM I2 is BLOCKED

5153 I2 ACTIVE AM I2 is ACTIVE

5156 I2> Warn AM Unbalanced load: Current warning stage

5158 RM th.rep. I2 AM Reset memory of thermal replica I2

5159 I2>> picked up AM I2>> picked up

5160 I2>> TRIP AM Unbalanced load: TRIP of current stage

5161 I2 Θ TRIP AM Unbalanced load: TRIP of thermal stage

5165 I2> picked up AM I2> picked up

Comments

7UM61 Manual

C53000-G1176-C127-3

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)

www . ElectricalPartManuals . com

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)

The underexcitation protection protects a synchronous machine from asynchronous operation in the event of faulty excitation or regulation and from local overheating of the rotor. Furthermore, it avoids endangering network stability by underexcitation of large synchronous machines.

2.11.1 Function Description

Underexcitation Determination

Characteristic Curves

In order to detect underexcitation, the unit processes all three terminal phase currents and all three terminal voltages to form the stator circuit criterion.

For the stator circuit criterion the admittance is calculated from the positive sequence currents and voltages. The admittance measurement always produces the physically appropriate stability limit, independently of voltage deviations from rated voltage. Even in such circumstances the protection characteristic can be thus optimally matched to the stability characteristic of the machine. By virtue of the positive sequence system evaluation, protection operates reliably even during asymmetrical current or voltage conditions.

The following figure shows the loading diagram of the synchronous machine in the admittance plane (P/U axis near 1/X

; –Q/U2) with the statistic stability limit which crosses the reactive

(reciprocal value of the synchronous direct reactance).

Figure 2-19 Admittance Diagram of Turbo Generators

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

The underexcitation protection in the 7UM61 makes available three independent, freely combinable characteristics. As illustrated in the following figure, it is possible for example to model static machine stability by means of two partial characteristics with the same time delays (T CHAR. 1 = T CHAR 2). The partial characteristics are distinguished by the corresponding distance from the zero point (1/xd CHAR. 1) and (1/xd

CHAR. 2) as well as the corresponding inclination angle α If the resulting characteristic (1/xd CHAR.1)/α

following figure on the left), a delayed warning (e.g. by 10 s) or a trip signal is transmitted. The delay is necessary to ensure that the voltage regulator is given enough time to increase the excitation voltage.

; (1/xd CHAR.2)/α

and α

is exceeded (in the

Figure 2-20 Stator circuit criterion: Pick–Up Characteristic in Admittance Diagram

Excitation Voltage Query

Undervoltage Blocking

A further characteristic (1/xd CHAR.3 /α

characteristic of the synchronous machine. Since stable operation is impossible if this characteristic is exceeded, immediate tripping is then required (time stage T CHAR 3).

With a faulty voltage regulator or excitation voltage failure, it is possible to switch off with a short delay (time stage T SHRT Uex<, e.g. 1.5 s). For this purpose, excitation voltage failure must be communicated to the device via a binary input.

The admittance calculation requires a minimum measurement voltage. During a severe collapse (short-circuit) or failure of stator voltages, the protection is blocked by an integrated AC voltage monitor whose pickup threshold 3014 Umin is set on delivery to 25 V. The parameter value is based on phase-to-phase voltages.

can be matched to the dynamic stability

7UM61 Manual

C53000-G1176-C127-3

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)

www . ElectricalPartManuals . com

The following figure shows the logic diagram for underexcitation protection.

Figure 2-21 Logic diagram of the Underexcitation Protection

2.11.2 Setting Notes

General The underexcitation protection is only effective and available if this function was set

during protective function configuration (Section 2.2, address 130, UNDEREXCIT. is set to Enabled. If the function is not required Disabled is set. The address 3001 UNDEREXCIT. serves to enable the function ON and OFF or to block only the trip command (Block relay).

The correct power system data input according to Section 2.3 is another prerequisite for the parameterization of the underexcitation protection.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

The trip characteristics of the underexcitation protection in the admittance value diagram are composed of straight segments which are respectively defined by their

admittance 1/xd (=coordinate distance) and their inclination angle α. The straight segments (1/xd CHAR.1)/α

form the static underexcitation limit (see the following figure). (1/xd CHAR.1) corresponds to the reciprocal value of the related synchronous direct reactance.

If the voltage regulator of the synchronous machine has underexcitation limiting, the static characteristics are set in such a way that the underexcitation limiting of the voltage regulator will intervene before characteristic 1 is reached (see figure 2-24).

(characteristic 1) and (1/xd CHAR.2)/α

(characteristic 2)

Characteristic Curve Values

Figure 2-22 Underexcitation Protection Characteristics in the Admittance Plane

If the generator capability diagram (see the following Figure) in its preferred representation (abscissa = positive reactive power; ordinate = positive active power) is transformed to the admittance plane (division by U matched directly to the stability characteristic of the machine. If the axis sizes are divided by the nominal apparent power, the generator diagram is indicated per unit (this diagram corresponds to a per unit representation of the admittance diagram).

), the tripping characteristic can be

7UM61 Manual

C53000-G1176-C127-3

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)

www . ElectricalPartManuals . com

Figure 2-23 Capability Curve of a Salient-Pole Generator, Indicated per Unit

The primary setting values can be read out directly from the diagram. The related values must be converted for the protection setting. The same conversion formula can be used if the protection setting is performed with the predefined synchronous direct reactance.

with

related synchronous direct reactance, secondary,

dsec

related synchronous direct reactance of the machine,

d mach

Nominal Current of the Machine

NMach

Nominal Voltage of the Machine

NMach

N VT. prim

N CT prim

Instead of 1/x current at no-load excitation).

Primary Nominal Voltage of the voltage transformers

Nominal primary CT current

the approximate value IK0/IN can be used (with IK0 = short-circuit

d mach

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Setting example:

Machine U

Current Transformer

Voltage transformer

Multiplied by a safety factor of about 1.05, the setting value 1/xd CHAR. 1 results under address 3002.

For α1, the angle of the underexcitation limiting of the voltage regulator is selected or

the inclination angle of the machine stability characteristic is used. The setting value

ANGLE 1 is typically situated between 60 ° and 80 °.

In most cases, the machine manufacturer prescribes a minimum excitation value for small active powers. For this purpose, characteristic 1 is cut from characteristic 2 for low active-power load. Consequently, 1/xd CHAR. 2 is set to about 0.9· (1/xd

CHAR. 1), the ANGLE 2 to 90 °. The kinked tripping limit according to figure 2-22

(CHAR. 1, CHAR. 2) results in this way, if the corresponding time delays T CHAR. 1 and T CHAR. 2 of both characteristics are set equally.

N, Mach

N Machine

d mach

N CT prim

N VT. prim

= 6.3 kV

= SN/√3 UN = 5270 kVA/√3 · 6.3 kV = 483 A

= 2.47 (read from machine manufacturer's specifications in Figure 2-23)

= 500 A

= 6.3 kV

Characteristic 3 serves to adapt the protection to the dynamic machine stability limits. If there are no precise indications, the user must select a value 1/xd CHAR. 3, approximately between the synchronous direct reactance xd and the transient reactance

'. However, it should be greater than 1.

A value between 80 ° and 110 ° is usually selected for the corresponding ANGLE 3,

which ensures that only a dynamic instability can lead to a pickup with characteristic

3. The associated time delay is set at address 3010 T CHAR 3 to the value suggested in Table 2-4.

Figure 2-24 Admittance diagram of a turbogenerator

7UM61 Manual

C53000-G1176-C127-3

2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)

www . ElectricalPartManuals . com

Delay Times If the static limit curve consisting of the characteristics 1 and 2 is exceeded, the voltage

regulator must first have the opportunity of increasing the excitation. For this reason, a warning message due to this criterion is ”long-time" delayed (at least 10 s for 3004 T CHAR. 1 and 3007 T CHAR. 2).

However if an external excitation monitoring signals the failure of an excitation voltage to the device via a binary input, a switch-off can be performed with a short time delay.

Table 2-4 Setting the Underexcitation Protection

Characteristic 1 and 2 static stability undelayed Annunciation:

Exc < Anr

Characteristic 1 and 2 static stability long-time delayed

T CHAR. 1 = T CHAR. 2 ≈

10 s

Characteristic 1 and 2 Excitation Voltage Failure

Characteristic 3 dynamic stability short–time delayed

Note: If very short time delays are selected, dynamic balancing procedures may cause unwanted operations. For this reason, it is recommended to set time values of

0.05 s or higher.

short–time delayed

T SHRT Uex< ≈ 1.5 s

T CHAR 3 ≈ 0.5 s

Trippings Err<1 TRIP / Err<2 TRIP

Tripping Err< UPU < TRIP

Tripping Exc<3 TRIP

2.11.3 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

Addr. Parameter Setting Options Default Setting Comments

3001 UNDEREXCIT. OFF

ON Block relay

3002 1/xd CHAR. 1 0.25 .. 3.00 0.41 Conductance Intersect Character-

3003 ANGLE 1 50 .. 120 ° 80 ° Inclination Angle of Characteristic

3004 T CHAR. 1 0.00 .. 60.00 sec; ∞ 10.00 sec Characteristic 1 Time Delay

3005 1/xd CHAR. 2 0.25 .. 3.00 0.36 Conductance Intersect Character-

3006 ANGLE 2 50 .. 120 ° 90 ° Inclination Angle of Characteristic

3007 T CHAR. 2 0.00 .. 60.00 sec; ∞ 10.00 sec Characteristic 2 Time Delay

3008 1/xd CHAR. 3 0.25 .. 3.00 1.10 Conductance Intersect Character-

3009 ANGLE 3 50 .. 120 ° 90 ° Inclination Angle of Characteristic

OFF Underexcitation Protection

istic 1

istic 2

istic 3

3010 T CHAR 3 0.00 .. 60.00 sec; ∞ 0.30 sec Characteristic 3 Time Delay

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Addr. Parameter Setting Options Default Setting Comments

3011 T SHRT Uex< 0.00 .. 60.00 sec; ∞ 0.50 sec T-Short Time Delay (Char. &

Uexc<)

3014A Umin 10.0 .. 125.0 V 25.0 V Undervoltage blocking Pickup

2.11.4 Information List

No. Information Type of In-

formation

5323 >Exc. BLOCK EM >BLOCK underexcitation protection

5327 >Char. 3 BLK. EM >BLOCK underexc. prot. char. 3

5328 >Uexc fail. EM >Exc. voltage failure recognized

5329 >Char. 1 BLK. EM >BLOCK underexc. prot. char. 1

5330 >Char. 2 BLK. EM >BLOCK underexc. prot. char. 2

5331 Excit. OFF AM Underexc. prot. is switched OFF

5332 Excit.BLOCKED AM Underexc. prot. is BLOCKED

5333 Excit.ACTIVE AM Underexc. prot. is ACTIVE

5334 Exc. U< blk AM Underexc. prot. blocked by U<

5336 Uexc failure AM Exc. voltage failure recognized

5337 Exc< picked up AM Underexc. prot. picked up

5343 Exc<3 TRIP AM Underexc. prot. char. 3 TRIP

5344 Exc<1 TRIP AM Underexc. prot. char. 1 TRIP

5345 Exc<2 TRIP AM Underexc. prot. char. 2 TRIP

5346 Exc<U<TRIP AM Underexc. prot. char.+Uexc< TRIP

Comments

7UM61 Manual

C53000-G1176-C127-3

2.12 Reverse Power Protection (ANSI 32R)

www . ElectricalPartManuals . com

Reverse power protection is used to protect a turbo-generator unit on failure of energy to the prime mover when the synchronous generator runs as a motor and drives the turbine taking motoring energy from the network. This condition leads to overheating of the turbine blades and must be interrupted within a short time by tripping the network circuit-breaker. For the generator there is the additional risk that with a malfunctioning residual steam pass (defective stop valves) after the switching off of the circuit breaker the turbine generator unit is accelerated to overspeed. For this reason, the system isolation should only be performed after the detection of active power input into the machine.

2.12.1 Function Description

2.12 Reverse Power Protection (ANSI 32R)

Reverse Power Determination

Pickup Seal-In Time To ensure that frequently occurring short pickups can cause tripping, it is possible to

Trip Signal For bridging a perhaps short power input during synchronisation or during power

The reverse power protection of the 7UM61 precisely calculates the active power from the symmetrical components of the fundamental waves of voltages and currents by averaging the values of the last 16 cycles. The evaluation of only the positive phasesequence systems makes the reverse power determination independent of current and voltage asymmetries and corresponds to actual loading of the drive end. The calculated active power value corresponds to the overall active power. By taking the error angles of the instrument transformers into account, the active power component is

exactly calculated even with very high apparent powers and low power factor (cos ϕ).

The correction is performed by a W0 constant correction angle determined during commissioning of the protection device in the system. The correction angle is set under Power System Data 1 (see Section 2.3).

perform a selectable prolongation of these pickup pulses at parameter 3105 T-HOLD. Each positive edge of the pickup pulses triggers this time stage again. For a sufficient number of pulses, the pickup signals adds up and become longer than the time delay.

swings caused by system faults, the trip command is delayed by a selectable time T- SV-OPEN . In case of a closed emergency tripping valve, a short delay is, however, sufficient. By means of entering the emergency tripping valve position via a binary input, the short time delay T-SV-CLOSED becomes effective under an emergency tripping condition. The time T-SV-OPEN is still effective as back-up stage.

It is also possible to block tripping via an external signal.

The following figure shows the logic diagram for the reverse power protection.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-25 Logic Diagram of the Reverse Power Protection

2.12.2 Setting Notes

General Reverse power protection is only effective and available if this function was set during

protective function configuration (Section 2.2, address 131, REVERSE POWER is set to Enabled. If the function is not required Disabled is set. The address 3101 REVERSE POWER serves to switch the function ON or OFF or to block only the trip command (Block relay).

In case of a reverse power, the turbine set must be disconnected from the system as the turbine operation is not permissible without a certain minimum steam throughput (cooling effect) or, in case of a gas turbine set, the motor load would be too heavy for the network.

Pickup Values The level of the active power input is determined by the friction losses to be overcome

and is in the following ranges, depending on the individual system:

• Steam turbines: P

• Gas turbines: P

• Diesel drives: P

For the primary test, the reverse power should be measured with the relay. The user should select a setting of 0.5 times the value of the measured motoring energy. This value can be found under the percentage operational measured values. The feature of correcting angle faults of the current and voltage transformers should be used especially in case of very large machines with a particularly low motoring energy (see sections 2.3).

Reverse/SN

≈ 1 % to 3 %

≈ 3 % to 5 %

> 5 %

7UM61 Manual

C53000-G1176-C127-3

2.12 Reverse Power Protection (ANSI 32R)

www . ElectricalPartManuals . com

The pickup value 3102 P> REVERSE is set in percent of the secondary apparent

· U

· I

power rating SNsec = √3

be converted to secondary quantities using the following formula:

with

Psec Secondary power corresponding to setting value

Nsec

. If the primary motoring energy is known, it must

Nsec

Secondary rated power = √3 · U

Nsec

Machine power corresponding to setting value

Mach

Pickup Seal-In Time The 3105 T-HOLD pickup seal-in time serves to extend pulsed pickups to the param-

eterized minimum duration.

Delay Times If reverse power without emergency tripping is used, a corresponding time delay must

be implemented to bridge any short reverse power states after synchronization or power swings subsequent to system faults (e.g. 3-pole short circuit). Usually, a delay time 3103 T-SV-OPEN = approx. 10 s is set.

Under emergency tripping conditions, the reverse power protection performs a shorttime delayed trip subsequent to the emergency tripping via an oil-pressure switch or a position switch at the emergency trip valve. Before tripping, it must be ensured that the reverse power is only caused by the missing drive power at the turbine side. A time delay is necessary to bridge the active power swing in case of sudden valve closing, until a steady state active power value is achieved. A 3104 T-SV-CLOSED time delay of about 1 to 3 s is sufficient for this purpose, whereas a time delay of about 0.5 s is recommended for gas turbine sets. The set times are additional time delays not including the operating times (measuring time, drop-out time) of the protective function.

Nominal apparent power of the machine

N, Mach

Nominal Voltage of the Machine

N, Mach

Nominal Current of the Machine

N Mach

Primary Nominal Voltage of the voltage transformers

N prim

Nominal primary CT current

N prim

Nsec

· I

Nsec

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.12.3 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

Addr. Parameter Setting Options Default Setting Comments

3101 REVERSE POWER OFF

ON Block relay

3102 P> REVERSE -30.00 .. -0.50 % -1.93 % P> Reverse Pickup

3103 T-SV-OPEN 0.00 .. 60.00 sec; ∞ 10.00 sec Time Delay Long (without Stop

3104 T-SV-CLOSED 0.00 .. 60.00 sec; ∞ 1.00 sec Time Delay Short (with Stop

3105A T-HOLD 0.00 .. 60.00 sec; ∞ 0.00 sec Pickup Holding Time

OFF Reverse Power Protection

Val ve)

2.12.4 Information List

No. Information Type of In-

formation

5083 >Pr BLOCK EM >BLOCK reverse power protection

5086 >SV tripped EM >Stop valve tripped

5091 Pr OFF AM Reverse power prot. is switched OFF

5092 Pr BLOCKED AM Reverse power protection is BLOCKED

5093 Pr ACTIVE AM Reverse power protection is ACTIVE

5096 Pr picked up AM Reverse power: picked up

5097 Pr TRIP AM Reverse power: TRIP

5098 Pr+SV TRIP AM Reverse power: TRIP with stop valve

Comments

7UM61 Manual

C53000-G1176-C127-3

2.13 Forward Active Power Supervision (ANSI 32F)

www . ElectricalPartManuals . com

2.13 Forward Active Power Supervision (ANSI 32F)

The machine protection 7UM61 includes an active power supervision which monitors whether the active power undershoots one set value or overshoots a separate second set value. Each of these functions can initiate different control functions.

When, for example, with generators operating in parallel, the active power output of one machine becomes so small that other generators could take over this power, then it is often appropriate to shut down the lightly loaded machine. The criterion in this case is that the "forwards" power supplied into the network falls below a certain value.

In many applications it can be desirable to issue a control signal if the active power output rises above a certain value.

When a fault in a utility network is not cleared within a critical time, the utility network and should be split or for example, an industrial network decoupled from it. As criteria for decoupling, in addition to power flow direction, are undervoltage, overcurrent and frequency. As a result, the 7UM61 can also be used for network decoupling.

2.13.1 Function Description

Active Power Measuring

Depending on the application either slow high-precision measurement (averaging 16 cycles) or high-speed measurement (without averaging) may be selected. High-speed measurement is particularly suitable for network de-coupling.

The device calculates the active power from the positive sequence systems of the generator currents and voltages. The computed value is compared with the set values. Each of the forward active power stages can be blocked individually via binary inputs. In addition the entire active power monitoring can be blocked per binary input.

The following figure shows the logic diagram for forward active power supervision.

Figure 2-26 Logic Diagram of the Forward Active Power Supervision

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.13.2 Setting Notes

General The forward active power protection is only effective and available if this function was

set on protective functions configuration (section 2.2, address 132, FORWARD POWER = to Enabled. If the function is not required Disabled is set. The address 3201 FORWARD POWER serves to switch the function ON or OFF or to block only the trip command (Block relay).

Pickup Values, Time Delays

The setting of the forward power protection depends very much on the intended purpose. General setting guidelines are not possible. The pickup values are set in percent of the secondary apparent power rating S machine power must be converted to secondary quantities:

with

Psec Secondary power corresponding to setting value

Secondary rated power = √3 · U

Nsec

Machine power corresponding to setting value

Mach

Address 3202 serves to set the threshold of the forward power to an undershoot (Pf<) and address 3204 (Pf>) serves to set it to overshoot. Addresses 3203 T-Pf< and 3205 T-Pf> serve to set the associated time delays.

Nominal apparent power of the machine

N, Mach

Nominal voltage of the machine

N, Mach

Nominal current of the machine

N Mach

Primary Nominal Voltage of the voltage transformers

N prim

Nominal primary CT current

N prim

Nsec

= √3 · U

Nsec

· I

Nsec

· I

. Consequently, the

Nsec

In address 3206 MEAS. METHOD the user can select whether a fast or a precise measuring procedure is to be used for the forward power calculation. In most cases, the precise measuring procedure is preferred in the power station sector (as a rule), whereas the fast procedure is applied for use as mains decoupling.

The set times are additional time delays not including the operating times (measuring time, drop-out time) of the protective function.

7UM61 Manual

C53000-G1176-C127-3

2.13 Forward Active Power Supervision (ANSI 32F)

www . ElectricalPartManuals . com

2.13.3 Settings

Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.

Addr. Parameter Setting Options Default Setting Comments

3201 FORWARD POWER OFF

ON Block relay

3202 Pf< 0.5 .. 120.0 % 9.7 % P-forw.< Supervision Pickup

3203 T-Pf< 0.00 .. 60.00 sec; ∞ 10.00 sec T-P-forw.< Time Delay

3204 Pf> 1.0 .. 120.0 % 96.6 % P-forw.> Supervision Pickup

3205 T-Pf> 0.00 .. 60.00 sec; ∞ 10.00 sec T-P-forw.> Time Delay

OFF Forward Power Supervision

3206A MEAS. METHOD accurate

fast

accurate Method of Operation

2.13.4 Information List

No. Information Type of In-

formation

5113 >Pf BLOCK EM >BLOCK forward power supervision

5116 >Pf< BLOCK EM >BLOCK forw. power superv. Pf< stage

5117 >Pf> BLOCK EM >BLOCK forw. power superv. Pf> stage

5121 Pf OFF AM Forward power supervis. is switched OFF

5122 Pf BLOCKED AM Forward power supervision is BLOCKED

5123 Pf ACTIVE AM Forward power supervision is ACTIVE

5126 Pf< picked up AM Forward power: Pf< stage picked up

5127 Pf> picked up AM Forward power: Pf> stage picked up

5128 Pf< TRIP AM Forward power: Pf< stage TRIP

5129 Pf> TRIP AM Forward power: Pf> stage TRIP

Comments

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

2.14 Impedance Protection (ANSI 21)

Machine impedance protection is used as a selective time graded protection to provide shortest possible tripping times for short-circuits in the synchronous machine, on the terminal leads as well as in the unit transformer. It thus also provides backup protection functions to the main protection of a power plant or protection equipment connected in series like generator, transformer differential and system protection devices.

2.14.1 Functional Description

Pickup

General Fault detection is required to detect a faulty condition in the power system and to ini-

tiate all the necessary procedures for selective clarification of the fault:

• Start the time delays for the final stage t3,

• Determination of the faulty measuring loop

• Enabling of impedance calculation,

• Enabling of tripping command,

• Indication/output of the faulty conductor(s).

Pickup is implemented as overcurrent pickup and can be optionally supplemented by an undervoltage seal-in circuit. After numeric filtering, the currents are monitored for over-shooting of a set value. A signal is output for each phase where the set threshold has been exceeded. These pickup signals are considered for choosing the measured values. The pickup is reset when 95% of the pick-up threshold is undershot, unless maintained by the undervoltage seal-in feature.

Undervoltage Seal-In Feature

Determination of the Short–Circuit Impedance

With excitation systems powered from the network, excitation voltage can drop during a local short circuit, resulting in decreasing short-circuit current which, in spite of the remaining fault, can undershoot the pickup value. In such cases pick-up is maintained for a settable time period by means of the undervoltage controlled seal-in circuit using the positive sequence voltage U1. Pickup drops off when this holding time has expired or when the restored voltage reaches 105% of the set undervoltage seal-in value.

The seal-in logic operates separate for each phase. The first pickup starts the timer T- SEAL-IN.

Figure 2-27 shows the logic diagram of the pickup stage of the impedance protection.

For calculating impedance only the currents and voltages of the faulty (shorted) phase loop are decisive. Accordingly the protection, controlled by the pickup, evaluates these measurement values (see also Table 2-5).

7UM61 Manual

C53000-G1176-C127-3

Loo p Sel ect ion

www . ElectricalPartManuals . com

2.14 Impedance Protection (ANSI 21)

• The corresponding phase-earth loop is used for a 1-pole pickup.

• With a 2-pole pickup, the phase-phase loop with the corresponding phase-to-phase voltage is used for impedance calculation.

• With a 3-pole pickup, the phase-phase loop with the highest current value is used and with equal current amplitudes, the procedure described in the last row of the following of table is applied.

Table 2-5 Measuring Loop Selection

Pickup Measuring Loop

1-pole L1

L2 L3

2-pole L1, L2

L2, L3 L3, L1

3-pole, with different amplitudes

3-pole, with equal amplitudes

L1,2*L2,L3 L2.2*L3,L1 L3.2*L2,L3

L1, L2, L3 Phase-earth, any,

Phase-earth L1–E

L2–E L3–E

Phase-phase, Calculation of U and I

I I

Phase-ground, selection of loop with the highest current

and I

I (Imax)

maximum current amount

I (Imax)

L1– L2 L2– L3

I I

L3– L1

L2–E L3–E L1–E

L1=IL2=IL3 then IL1

IL1=IL2 > IL3 then IL1 IL2=IL3 > IL1 then IL2 IL3=IL1 > IL2 then IL1

This loop selection type ensures that the fault impedance of system faults is measured correctly via the unit transformer. A measuring error occurs with a 1-pole system shortcircuit, since the zero phase-sequence system is not transmitted via the machine transformer (switching group e.g. Yd5). The following table describes the fault modeling and the measuring errors.

Table 2-6 Fault Modeling and Measuring Errors on the Generator Side on System Faults

System Faults Fault Model on

the Generator

Side

3–pole short circuit

2–pole short circuit

1–pole short circuit

3–pole short circuit

2–pole short circuit

Loop Selection Measuring

Errors

Phase-earth always correct

measurement

Phase-earth loop with highest current

Phase-phase loop

always correct measurement

Impedance measured too high by the zero impedance

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

Figure 2-27 Logic Diagram of the Pickup Stage of the Impedance Protection

Tripping Characteristic

The tripping characteristic of the impedance protection is a polygon (see also Figure 2-28). It is a symmetrical characteristic, even though a fault in reverse direction (negative R and/or X values) is impossible provided the usual connection to the current transformers at the star-point side of the generator is used. The polygon is fully identified by one parameter (impedance Z).

As long as the pickup criterion is met, impedance calculation is done continuously using the current and voltage vectors derived from the loop selection measured values. If the calculated impedance is within the trip characteristic, the protection issues a trip command which may be delayed according to the relevant delay time.

Since the impedance protection is multi-stage, the protected zones can be chosen such that the first stage (ZONE Z1, T-Z1) covers faults in the generator and the lower voltage side of the unit transformer, whereas the second stage (ZONE Z2, ZONE2 T2)

7UM61 Manual

C53000-G1176-C127-3

2.14 Impedance Protection (ANSI 21)

www . ElectricalPartManuals . com

covers the network. It should be noted that high voltage side 1-pole faults cause impedance measurement errors due to the star-delta connection of the unit transformer on the lower voltage side. An unwanted operation of the stage can be excluded since the fault impedances of power system faults are modeled too high.

Faults outside this range are switched off by the T END final time stage.

Depending on the switching status of the system, it may be useful to extend the ZONE Z1, T-Z1 undelayed tripping zone. If, for example, the high-voltage side circuit breaker is open, the pickup can only be caused by a fault in the power unit. If consideration of the circuit breaker auxiliary contact is possible, a so-called overreach zone ZONE Z1B can be made effective (see also Section 2.14.2, Grading of the Machine Impedance Protection figure).

Figure 2-28 Tripping Characteristics of the Impedance Protection

Tripping Logic

The T END time delay is started subsequent to the protection pickup, establishing the the fault loop. The loop impedance components are compared with the limit values of the zones previously set. The tripping is executed if the impedance is within its zone during the the course of the corresponding time stage.

For the first Z1 zone and also for the Z1B overreach zone, the time delay will in most cases be zero or at least very short. i.e. tripping occurs as soon as it is established that the fault is within this zone.

The Z1B overreach stage can be enabled from outside, via a binary input.

For the Z2 zone which may extend into the network, a time delay is selected overreaching the first stage of the power system protection.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

A drop-out can only be caused by a drop-out of the overcurrent pickup and not by exiting the tripping polygon.

The following figure shows the logic diagram for the impedance protection.

Figure 2-29 Logic Diagram of the Impedance Protection

2.14.2 Setting Notes

General Machine impedance protection is only effective and available if enabled during config-

uration (Section 2.2, address 133, IMPEDANCE PROT. = Enabled. If the function is not required Disabled is set. Address 3301 IMPEDANCE PROT. serves to switch the function ON or OFF or to block only the trip command (Block relay).

7UM61 Manual

C53000-G1176-C127-3

2.14 Impedance Protection (ANSI 21)

www . ElectricalPartManuals . com

Pickup The maximum load current during operation is the most important criterion for setting

overcurrent pickup. A pickup by an overload must be excluded! For this reason, the 3302 IMP I> pickup value must be set above the maximum (over) load current to be expected. Recommended setting: 1.2 to 1.5 times the nominal machine current. The pickup logic corresponds to the logic of the definite time-overcurrent protection.

If the excitation is derived from the generator terminals with the short circuit current possibly falling below the pickup value (address 3302) due to the collapsing voltage, the undervoltage seal-in feature of the pickup is used, i.e. address 3303 U< SEAL- IN is switched to ON.

The undervoltage seal-in setting U< (address 3304) is set to a value just below the lowest phase-to-phase voltage occurring during operation, e.g. to U< = 75 % to 80 % of the nominal voltage. The seal-in time (address 3305 T-SEAL-IN) must exceed the maximum fault clearance time in a back-up case (recommended setting: Address 3312 T END + 1 s).

Impedance Stages The protection has the following characteristics which may be set independently:

1. Zone (fast tripping zone Z1 ) with parameters

ZONE Z1 Reactance = reach,

T-Z1 = 0 or short delay, if required.

Overreach zone Z1B, externally controlled via binary input, with parameters

ZONE Z1B Reactance = reach,

T-Z1B T1B = 0 or short delay, if required.

2. Zone (zone Z2) with parameters

ZONE Z2 Reactance = reach,

ZONE2 T2 The user must select a value for T2 above the grading

time of the network protection.

Non-directional final stage with parameter

T END The user must select T END so that the 2nd or 3rd

stage of the series-connected power system distance protection is overreached.

As the user may assume that impedance protection measurement extends into the unit transformer, parametrization selection must sufficiently consider the transformer control range.

Therefore ZONE Z1 is normally set to a reach of approx. 70 % of the protected zone (i.e. about 70 % of the transformer reactance), with no or only a small delay (i.e. T-Z1 = 0.00 s to 0.50 s). Protection then switches off faults on this distance after its operating time or with a slight time delay (high speed tripping). A time delay of 0.1 s is preferred.

For ZONE Z2 the reach could be set to about 100 % of the transformer reactance, or in addition to a network impedance. The corresponding ZONE2 T2 time stage is to be set so that it overreaches the power system protective equipment of the following lines. The T END time is the last back-up time.

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

The following formula is generally valid for the primary impedance (with limiting to the unit transformer):

with

Protection zone reach [%]

Relative transformer short-circuit voltage [%]

Rated transformer power [MVA]

Machine-side rated transformer voltage [kV]

The derived primary impedances must be converted for the secondary side of the current and voltage transformers. In general:

The nominal current of the protection device (= secondary nominal current of the current transformer) is automatically considered by the device. You have already communicated the transformation ratios of the current and voltage transformers to the device by entering the nominal transformer values (see section 2.3).

Example:

Transformer data:

= 7 %

= 5.3 MVA

= 6.3 kV

Transformation ratios:

Current transformer ratio = 500 A / 1 A

7UM61 Manual

C53000-G1176-C127-3

2.14 Impedance Protection (ANSI 21)

www . ElectricalPartManuals . com

This results to a 70 % reach for zone 1:

The following secondary side setting value of zone 1 results at address 3306 ZONE Z1:

Note: The following ratio would result from the connection of a 5 A device to a 5 A current transformer:

Likewise the following primary reactance results for a 100 % reach for zone 2:

7UM61 Manual C53000-G1176-C127-3

2 Functions

www . ElectricalPartManuals . com

The following secondary side setting value of zone 2 results at address 3310 ZONE Z2:

Figure 2-30 Time Grading for Machine Impedance Protection – Example

Z1B Overreach Zone

Final Stage For short circuits outside the Z1 and Z2 zones, the device functions as a time-delayed

The Z1B overreach zone (address 3308 ZONE Z1B) is an externally controlled stage. It does not influence the Z1 zone normal stage. Consequently there is no changeover, but the overreach zone is enabled or disabled depending on the position of the highvoltage side circuit breaker.

The Z1B zone is usually enabled by an opened high-voltage circuit breaker. In this case every impedance protection pickup can only be due to a fault in the protection zone of the block, since the power system is disconnected from the block. Consequently the fast tripping zone can be extended to between 100 % and 120 % of the protection zone without any loss of selectivity.

The Z1B zone is activated via a binary input controlled by the circuit breaker auxiliary contact (see Figure 2-30). The overreach zone is allocated an individual 3309 T-Z1B time delay.

overcurrent protection. Its nondirectional final time T END is selected so that its time value overreaches the second or third stage of the series-connected network distance protection.

100

7UM61 Manual

C53000-G1176-C127-3

Siemens Siprotec 7UM611, Siprotec 7UM612 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Disclaimer of liability

Copyright

Registered Trademarks

Preface

Purpose of this Manual

Target Audience Protection engineers, commissioning engineers, personnel concerned with adjust-

Applicability of this Manual

Additional Support Should further information on the System SIPROTEC® 4 be desired or should partic-

Training Courses Individual course offerings may be found in our Training Catalogue, or questions may

Contents

Introduction 1

1.1 Overall Operation

Analog Inputs The measuring inputs (MI) are galvanically isolated, transform the currents and volt-

Microcomputer System

Binary Inputs and Outputs

F r o n t E l em e n ts Optical indicators (LEDs) and a front display panel (LC display) provide information on

S e r i a l I n t e r f a c e s A serial operator interface in the front cover is provided for local communication with

Power Supply The functional units described are supplied by a power supply PS with the necessary

1.2 Application Scope

Communication For communication with external operator, control and storage systems, serial inter-

Operator Interface on the Front Panel

1.3 Characteristics

Thermal Overload Protection

Negative Sequence Protection

Underexcitation protection

Vector Jump • Sensitive phase jump detection to be used for network disconnection.

90% Stator Earth Fault Protection

Sensitive Earth F a u l t P r o t e c t i o n

100% Stator Earth Fault Protection w i t h 3 r d H a r m o n i c

Motor Starting Time Supervision

Restart Inhibit for Motors

Breaker Failure Protection

Breaker Control • Circuit breakers can be opened and closed manually via programmable function

Measured Values Monitoring

Functions 2

2.1 Introduction, Reference Systems

2.1.1 Functional Description

Generator The calculation examples are based on two smaller capacity reference power systems

Technical Data of the Reference Power Systems

Transformer

Motor

2.2 Functional Scope

2.2.1 Functional Description

Configuration of the Functional Scope

2.2.2 Setting Notes

Special Cases Most settings are self-explanatory. The special cases are described below.

2.2.3 Settings

2.3 Power System Data 1

2.3.1 Setting Notes

General The Power System Data 1 can be changed via the operator or service interface from

Nominal Values of the Transformers

W0 Correction Angle

Iee Transformation Ratios

UE Transformation Ratio

Uph/Uen Adaption Factor

Phase Rotation Address 271 PHASE SEQ. is used to change the default phase sequence (L1 L2 L3

Operating Mode The 272 SCHEME setting is used for specifying if the generator to be protected is op-

ATEX100 Parameter 274 ATEX100 allows compliance with PTB requirements (special require-

Command Duration Address 280 is used to set the minimum time TMin TRIP CMD the tripping contacts

2.3.2 Settings

2.3.3 Information List

2.4 Change Group

2.4.1 Setting Notes

General If the changeover option is desired, on function extent configuration group changeover

2.4.2 Settings

2.4.3 Information List

2.5 Power System Data 2

2.5.1 Functional Description

Setting Groups In the 7UM61 relay, two independent setting groups (A and B) are possible. Whereas

2.5.2 Setting Notes

General To enter these group-specific general protection data (P.System Data 2), select in

Rated Values of the System

2.5.3 Settings

2.5.4 Information List

2.6 Definite-Time Overcurrent Protection (I>, ANSI 50/51) with Undervoltage Seal-In

2.6.1 Functional Description