Rockwell Automation 1557 User Manual

Medium Voltage AC Drive

Bulletin 1557

User Manual

Important User Information

IMPORTANT

Read this document and the documents listed in the Additional Resources section about installation, configuration, and operation of this equipment before you install, configure, operate, or maintain this product. Users are required to familiarize themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws, and standards.

Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to be carried out by suitably trained personnel in accordance with applicable code of practice.

If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.

In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment.

The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and diagrams.

No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual.

Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited.

Throughout this manual, when necessary, we use notes to make you aware of safety considerations.

WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss.

ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.

Identifies information that is critical for successful application and understanding of the product.

Labels may also be on or inside the equipment to provide specific precautions.

SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present.

BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous temperatures.

ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to potential Arc Flash. Arc Flash will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL Regulatory requirements for safe work practices and for Personal Protective Equipment (PPE).

Allen-Bradley, Rockwell Software, Rockwell Automation, and TechConnect are trademarks of Rockwell Automation, Inc.

Trademarks not belonging to Rockwell Automation are property of their respective companies.

TABLE OF CONTENTS

Chapter 1 .......................................................... Using This Manual

Chapter 2 ......................................................... Introduction

Chapter 3 .......................................................... Specifications

Chapter 4 .......................................................... Hardware Description

Chapter 5 .......................................................... Description of Operation

Chapter 6 .......................................................... Parameter and Variable

Descriptions

Chapter 7 .......................................................... Operator Interface Terminal

Chapter 8 .......................................................... Installation

Chapter 9 .......................................................... Commissioning

Chapter 10 ........................................................ Troubleshooting

Chapter 11 ........................................................ Spare Parts

1557-UM050F-EN-P – June 2013

USING THIS MANUAL 1-1

Warnings tell readers where people may be hurt if procedures are not followed properly.

Cautions tell readers where machinery may be damaged or economic loss can occur if procedures are not followed properly.

This symbol alerts the user to a potential electrical shock hazard which exists on a component or printed circuit board.

Manual Objectives

This manual is intended for use by personnel familiar with Medium Voltage and variable speed solid-state drive equipment. The manual contains material which will allow the user to operate, maintain, and troubleshoot the drive system.

IMPORTANT USER INFORMATION

Because of the variety of uses for this equipment and because of the differences between this solid-state equipment and electromechanical equipment, the user of and those responsible for applying this equipment must satisfy themselves as to the acceptability of each application and use of the equipment. In no event will Rockwell Automation be responsible or liable for indirect or consequential damages resulting from the use or modification of this equipment.

The illustrations shown in this manual are intended solely to illustrate the text of this manual Because of the many variables and requirements associated with any particular installation, Rockwell Automation cannot assume responsibility or liability for actual use based upon the illustrative uses and applications.

No patent liability is assumed by Rockwell Automation with respect to use of information, circuits, equipment or software described in this text.

Reproduction of the content of this manual, in whole or in part, without written permission of Rockwell Automation is prohibited.

Both of these:

• Identify a possible trouble spot.

• Tell what causes the trouble.

• Give the result of improper action.

• Tell the reader how to avoid trouble.

1557-UM050F-EN-P – June 2013

1-2 USING THIS MANUAL

REPAIR OR REPAIR/EXCHANGE PROCEDURE

For your convenience, Rockwell Automation and Rockwell Automation Global Technical Services(GTS), provide an efficient and convenient method of returning equipment eligible for repair or repair/exchange.

A Product Service Report (P.S.R.) number is required to return any equipment for repair. This may be obtained from your area Rockwell Automation Distributor, Sales Office or Area Support Division.

Return any equipment to be repaired to the Area Support Division nearest you. Be sure to reference the P.S.R. number on the carton and packing slip. Include your company name and address, your repair purchase order number, and a brief description of the problem. This will facilitate quick return of your equipment.

A complete listing of Global Technical Services offices may be obtained by calling your area Rockwell Automation Distributor or Sales Office.

1557-UM050F-EN-P – June 2013

INTRODUCTION CHAPTER 2

The Bulletin 1557 drive is a Pulse Width Modulated Current Source Machine side converter (PWM - CSI). It is designed to supply 3 phase currents to standard induction motor loads. The Bul. 1557 MV (medium voltage) drive converts 3 phase 50/60 Hz input power to an adjustable AC frequency current source for speed control of AC squirrel cage motors.

The solid state technology used in the design is of proven reliability. A number of circuit implementation techniques used are unique to the Allen-Bradley Bulletin 1557 drive.

The basic design philosophy emphasizes the isolation of single component failures, such that multiple component failures do not occur. This leads to a low MTTR, (Mean Time To Repair), with extensive fault diagnostic circuits and easy accessibility.

The basic design features of the Allen-Bradley Bulletin 1557 drive are as follows: The three phase motor currents are sinusoidal with low total harmonic distortion. The design uses isolated driver circuits, one per gate turn off thyristor (GTO), and

silicon controlled line side converter (SCR). Two output phases are individually current sensed, ensuring protection and control.

The design is capable of producing smooth low speed torque with low harmonic current to the motor.

A fuseless electronic protection scheme is used in the power circuit for normal fault conditions. Power fuses provide back up protection and ensure safety.

Heatsinks are monitored with temperature sensors to detect overtemperatures. (BUL 1557 Air-cooled units only)

The 1557 Drive uses a North American design base with all components readily accessible from the front without need to extensively dismantle the unit.

The drive system logic is microcomputer based, thus eliminating numerous trimpots for system calibration.

Fault and alarm indication is performed using an operator interface panel.

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2-2 INTRODUCTION

An Input contactor with fused isolating switch is optional on the 1557 drive and is only supplied

when specified or if the customer does not have an existing full voltage starter.

The standard 1557 drive is a tachless design. A tachometer is recommended for applications

requiring an output frequency lower than 6 hertz or applications with a starting torque greater than 30%.

A drive isolation transformer or AC line reactor is required with each drive. An isolation

transformer is mandatory when existing motors are used, 12-Pulse line side converters are used, or for stepping down the main supply voltage. An AC line reactor may only be used when new motors are used with the proper level of phase to ground insulation. Consult your Rockwell Automation representative for more information.

1557-UM050F-EN-P – June 2013

SPECIFICATIONS CHAPTER 3

The electrical and environmental specifications of the Bulletin 1557 MV Drive are provided below:

Input Voltages: 2300Vac ± 10%, 3-Phase 3300Vac ± 10%, 3-Phase 4160Vac ± 10%, 3-Phase 6900Vac ± 10%, 3-Phase

Input Frequency: 50/60Hz ± 3Hz

Efficiency: 97% at full load (minimum)

Output Voltage: 0 to 2300Vac, 3-Phase 0 to 3300Vac, 3-Phase 0 to 4160Vac, 3-Phase 0 to 6900Vac, 3-Phase

Output Frequency: 6Hz to 75Hz (Without Tach)

0.2Hz to 75 Hz (With Tach) Speed Regulation: 0.5% of maximum speed (Without Tach)

0.1% of maximum speed (With Tach) Speed Reference: 0 to 10V dc or

4 to 20 mA dc

Operating Temperature: Ambient temperature must be within the range of 0° to 40°C

with a relative humidity of up to 95% (non-condensing)

Storage Temperature: Ambient temperature must be within the range of –40° to 70°C

Altitude: No derating below 1000 m above sea level

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3-2 SPECIFICATIONS

1557-UM050F-EN-P – June 2013

HARDWARE DESCRIPTION 4-1

Hardware Overview

The basic drive consists of two cabinets; the D.C. link/control cabinet and the converter cabinet. An input contactor cabinet is optional. (See Figure 4.1)

Figure 4.1 – Outline of 1557 Drive

1557-UM050F-EN-P – June 2013

4-2 HARDWARE DESCRIPTION

DC Link Control Cabinet

The D.C. link/control cabinet is 44 inches wide. The top section has a panel with operator interface devices mounted on a door within a door. A fully vented door is in the bottom position.

Access to the low voltage control compartment is gained through the hinged low voltage panel. All low voltage compartments contain the following elements:

4.2 (A) Fiber optic interface boards ( 2 )

4.2 (B) Drive control boards ( 2 for 6-pulse, 3 for 12-pulse )

4.2 (C) Communication processor board ( 1 )

4.2 (D) Digital I/O boards ( 2 )

4.2 (E) D.C./D.C. converter ( 1 )

4.2 (F) A.C./D.C. power supply ( 1 )

4.2 (G) Capacitors See Figure 4.2

Figure 4.2 – Typical Low Voltage Compartment

1557-UM050F-EN-P – June 2013

HARDWARE DESCRIPTION 4-3

Warning: Allow 5-10 minutes for motor filter capacitors to safely discharge voltage prior to opening cabinet doors.

D.C. Link Reactor

The D.C. link reactor is floor mounted and may be shipped separately and installed on site in larger drives.

Motor Filter Capacitors

Located behind the low voltage compartment, the motor filter capacitors are accessible when the upper medium voltage door is opened. There are 3 capacitors for low horsepower drives and 6 for larger drives. The capacitors are liquid filled and mounted on rails. The metal cases of the capacitors are grounded to the cabinet.

1557-UM050F-EN-P – June 2013

4-4 HARDWARE DESCRIPTION

4.3(A)

4.3(D)

4.3(F)

4.3(B)

4.3(C)

4.3(E)

Line side converter Components

The line side converter is located in the lower half of the converter cabinet. The line side converter consists of three identical cells; each cell consists of the following:

4.3 (A) -line side converter heatsink stack

-Silicon Controlled Line side converter (SCR) thyristors

-heatsinks

-clamp

4.3 (B) -snubber capacitors

4.3 (C) -snubber resistors

4.3 (D) -voltage sharing/diagnostic resistors

4.3 (E) -gate driver circuit boards

4.3 (F) -power supply boards (See Figure 4.3 )

Figure 4.3 – Line Side Converter Components

(2300 V Line Side Converter shown)

1557-UM050F-EN-P – June 2013

HARDWARE DESCRIPTION 4-5

4.4(A)

4.4(E)

4.4(D)

4.4(G)

4.4(C)

4.4(D)

4.4(B)

4.4(F)

Machine side converter Components

The machine side converter is located in the upper half of the converter cabinet. The machine side converter consists of three identical cells. each cell consists of the following:

4.4 (A) -machine side converter heatsink stack assemblies

-Gate Turn Off (GTO) thyristors

-heatsinks

-clamp

4.4 (B) -snubber resistors

4.4 (C) -snubber capacitors

4.4 (D) -snubber diode assemblies

- Fast recovery diode

- diode clamp

-snubber capacitors for the snubber diodes

-snubber resistors for the snubber diodes

4.4 (E) -voltage sharing/diagnostic resistors

4.4 (F) -gate driver circuit boards

4.4 (G) -power supply boards (See Figure 4.4 )

Figure 4.4 – Machine Side Converter Components

(2300 V Machine Side Converter shown)

Three of the machine side converter heatsink assemblies (one in each phase) have thermistors mounted on the heatsinks, each thermistors is wired to a small circuit board (Thermistor Feedback board) which is located near the gate driver boards. In the event of heatsink overtemperature, a fault signal is sent to the controller and the drive will shut down.

1557-UM050F-EN-P – June 2013

4-6 HARDWARE DESCRIPTION

Voltage Feedback Circuit Boards

Voltage feedback boards are located in the converter cabinet on the far left side mounted on a vertical glass polyester channel. The boards consist of series connected resistors for sensing input voltage, DC link voltage, and output voltage.

Cooling Fans

There are several different arrangements of cooling fans. Fans are required to remove heat from the drive to ensure proper operation of its components. The fans draw air into the drive through the vented lower doors and exhaust it through vented enclosures at the top of the drive.

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION CHAPTER 5

Introduction ......................................................................................................................... 1

Speed Command ................................................................................................................ 3

Skip Speeds ........................................................................................................................ 5

Speed Ramp ....................................................................................................................... 7

Speed Control ..................................................................................................................... 9

Flux Control ....................................................................................................................... 11

Flux Control for Synchronous Motor .................................................................... 13

Current Control .................................................................................................................. 14

Line Converter Feedback .................................................................................................. 16

Machine Converter Feedback ........................................................................................... 18

Motor Model ...................................................................................................................... 20

Line Converter Protection ................................................................................................. 22

Machine Converter Protection .......................................................................................... 24

Analog Outputs ................................................................................................................. 26

Test Modes ....................................................................................................................... 28

Synchronous Transfer ....................................................................................................... 29

Transfer To Bypass ........................................................................................................... 30

Transfer To Drive .............................................................................................................. 31

Thyristor Diagnostics

Bulletin 1557 Drive ............................................................................................... 33

Bulletin 1557M Mini Drive .................................................................................... 35

Flying Start ................................................................................................................ 36

Tachometer/Encoder Option ............................................................................................. 37

1557-UM050F-EN-P –June 2013

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-1

Introduction The Bulletin 1557 is an adjustable speed ac drive in which motor speed control is achieved through

control of the motor torque. The motor speed is measured and the torque is adjusted as required to make the measured speed equal to the speed command. The stator frequency is determined by the motor and load and the drive synchronizes itself to the motor. This is in contrast to the more common volts/hertz ac drive in which the drive determines the stator frequency and does not attempt to synchronize its output to the motor.

The method of control used is known as direct vector control. The term vector control indicates that the position of the stator current vector is controlled relative to the motor flux vector. Direct vector control means that the motor flux is measured, in contrast to the more common indirect vector control in which the motor flux is predicted. In both cases, the stator current is resolved into flux producing and torque producing components which are controlled independently. The intent is to achieve performance similar to a dc machine, in which the torque can be changed quickly without affecting the flux. The flux cannot be changed quickly because of the rotor time constant, which is in the range of seconds for large machines.

The following description of operation is organized in the same functional blocks as the control block diagram (Figure 5.1). Most of the functions are the same as those found in any adjustable speed ac or dc drive. The features which are unique to a direct vector controlled drive are confined to the motor model and flux control functions.

The Bulletin 1557 drive can be used with either induction (asynchronous) or synchronous motors. Synchronous motor drives are identical to induction motor drives except for the addition of a current regulated field supply to the synchronous drive. The features that are unique to a synchronous drive are confined to the flux control function and the encoder option.

1557-UM050F-EN-P –June 2013

5-2 DESCRIPTION OF OPERATION

SPEED

COMMAND

SPEED

RAMP

SPEED

CONTROL

MOTOR

MODEL

LINE

CONVERTER

FEEDBACK

CURRENT

CONTROL

FLUX

CONTROL

SKIP

SPEEDS

LINE

CONVERTER

PROTECTION

MACHINE

CONVERTER

PROTECTION

MACHINE

CONVERTER

FEEDBACK

SYNCHRONOUS

TRANSFER

Flux

Feedback

Slip

Speed

Magnetizin

g Current

Command

Torque

Current

Comand

Stator

Frequency

Tach

Feedback

MOTOR

Faults

Voltage

Feedback

Current

Feedback

Link

Motor Filter

Capacitor

Faults

Voltage

Feedback

Current

Feedback

Line

Converter

Machine

Converter

Line

Converter

Firing Angle

Machine

Converter

Firing Angle

(Pxxx) Indicates a read/write parameter with a linear number of xxx.

(Vxxx) Indicates a read only variable with a linear number of xxx.

Speed

Commands

Figure 5.1

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-3

Speed Command

The function of the speed command block is to select one of 12 possible speed command inputs to serve as the drive speed command. Bits 12-15 of the Logic Command are used to select the Speed Command Input from the following list:

2 analog inputs (0-10V) 3 preset speed commands 6 SCANbus ports 1 preset jog speed command

The two analog speed command inputs accept 0-10V signals. The range of each of the analog inputs is defined by two parameters. These parameters can be adjusted to cause the speed command to either increase or decrease with an increasing analog input.

The six SCANport ports are multiplexed into a single SCANport input. The range of the digital input is defined by two parameters in the same way as the analog inputs.

The selected speed command input is clamped to a minimum level set by parameter Speed Command Minimum and a maximum level set by parameter Speed Command Maximum. (See Parameter and Variable Description in Chapter 6.)

1557-UM050F-EN-P –June 2013

5-4 DESCRIPTION OF OPERATION

0V 10V

A/D

Speed cmd 0 max (P42)

Speed cmd 0 min (P41)

Analog

input 1L

(V353)

Line

AI1

ANALOG SPEED

COMMAND INPUT

0V 10V

A/D

Speed cmd 8 max (P44)

Speed cmd 8 min (P43)

Analog

input 1M

(V355)

Machine

AI1

ANALOG SPEED

COMMAND INPUT

0 32767

Speed cmd 9 max (P46)

Speed cmd 9 min (P45)

DIGITAL SPEED

COMMAND INPUT

SCANport input (V398)

Speed command 0

(V273)

0000 (0)

Preset speed 1

(P33)

0001 (1)

Preset speed 2

(P34)

0010 (2)

Preset speed 3

(P35)

0011 (3)

Speed command 8

(V274)

1000 (8)

1001 (9)

1010 (10)

1011 (11)

1100 (12)

1101 (13)

1110 (14)

Preset jog speed

(P40)

1111 (15)

Speed Command in

(V276)

Speed command 9

(V275)

Speed cmd max

(P48)

Speed cmd min

(P47)

to skip speed

processing

Logic command bits 12 - 15 (spd cmd select)

(V258)

Speed Command

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-5

Skip Speeds

Four skip speeds are provided which may be used to prevent the drive from continuously operating at certain speeds, usually to avoid exciting mechanical resonance. Each of the four skip speed zones is defined by two parameters that specify its center point and width. Skip speed zones that overlap are merged.

After skip speed processing, the speed command input has its sign changed if reverse rotation is selected, or is set to zero if there is no run request.

1557-UM050F-EN-P –June 2013

5-6 DESCRIPTION OF OPERATION

Skip speed 1

(P49)

Skip speed 2

(P50)

Skip speed 4

(P52)

Skip speed 3

(P51)

Skip speed

band 1

(P53)

Skip speed

band 2

(P54)

Skip speed

band 3

(P55)

Skip speed

band 4

(P56)

from speed

command limit

-1

Speed command

(V277)

Logic status bit 1 (V258)

(Running)

Logic status bit 2 (V258)

(Forward command)

Skip Speeds

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-7

Speed Ramp

The function of the speed ramp is to control the rate of change of the drive speed reference. Independent four section ramps are provided for acceleration and deceleration. Each ramp is defined by four speed points which are specified by parameters Ramp Speed 1 to 4 which are the same for both accelerating and decelerating, and four time intervals which are specified by parameters Acceleration Time 1 to 4 and Deceleration Time 1 to 4. The input to the speed ramp is the speed command from the skip speed block. The drive control selects the appropriate acceleration or deceleration rate based on the present value of the ramp output and whether it is increasing or decreasing. The output of the speed ramp is the speed reference, which is the input to the speed control block. If the motor is coasting and speed feedback is available, the speed reference is set equal to the motor speed.

1557-UM050F-EN-P –June 2013

5-8 DESCRIPTION OF OPERATION

Accel

time 1

(P65)

Accel

time 2

(P66)

Accel

time 3

(P67)

Accel

time 4

(P68)

Decel

time 4

(P65)

Decel

time 3

(P66)

Decel

time 2

(P67)

Decel

time 1

(P68)

Ramp speed 3

(P75)

Ramp speed 2

(P74)

Ramp speed 1

(P73)

Ramp speed 4

(P76)

Speed

Reference

(V278)

Speed Ramp

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-9

Speed Control

The function of the speed control block is to determine the torque current command. The inputs are the speed reference from the speed ramp, and the stator frequency and slip frequency from the motor model.

Either tach feedback is used, or the slip frequency is subtracted from the stator frequency to determine the motor speed, which is then made negative if the motor is rotating in reverse. The result is filtered by an adjustable second order low pass filter to obtain the drive speed feedback.

The speed feedback is subtracted from the speed reference to determine the speed error. Parameter Speed Reference Step, which is used to demonstrate the step response of the speed loop, is added to the speed error to form the input to the speed regulator. The response of the speed regulator is determined by parameters Speed Regulator Bandwidth and Total Inertia. The rate of change of the speed regulator output is limited to the value specified by parameter Torque Rate Limit. The output of the speed regulator is clamped to the value specified by parameter Torque Limit Motoring for positive values and to the value specified by parameter Torque Limit Braking for negative values. The clamped output of the speed regulator is the torque reference. This is divided by the flux reference to determine Isq Command, which is the torque component of the stator current command.

Without a tachometer, reliable speed feedback is not available at stator frequencies below about 5 Hz. The speed regulator is therefore disabled at low speed and the torque reference is determined by open loop programming. The torque reference changes linearly from the value specified by parameter Torque Command 0 at zero speed to the value specified by parameter Torque Command 1 at Ramp Speed 1, and remains constant above this speed if the drive is still in start mode. When tach feedback is enabled the open loop torque programming is not used.

An estimate of the torque producing current supplied by the motor filter capacitor is calculated from Isq Command, stator frequency, and parameters Total Leakage Inductance and Filter Capacitor. The resulting value is called Icq Command and is subtracted from Isq Command to determine Iy Command, which is the torque component of the dc link current command.

1557-UM050F-EN-P –June 2013

5-10 DESCRIPTION OF OPERATION

Tach

feedback

(V348)

Slip

frequency

(V343)

Stator

frequency

(V337)

Speed Feedback Mode

(P89)

-1

Logic status bit 3 (V258)

(Forward rotation)

SPEED

FEEDBACK

FILTER

Speed fdbk filter

(P110)

Speed

reference

(V278)

from

sync

transfer

Sync spdref

SPEED

REGULATOR

RATE

LIMIT

TORQUE

LIMITING

Trq command 0

(P86)

Trq command 1

(P87)

Ramp speed 1

(P73)

Speed ref step (P88)

Speed

error

(V290)

Spdreg

bandwidth

(P81)

Total

Inertia

(P82)

Trq rate

limit (P83)

Start mode

STARTING TORQUE

PROGRAMMING

Trq limit

motoring

(P84)

Trq limit

braking

(P85)

Filter capacitor

(P133)

SPEED CONTROL

L Total

leakage

(P130)

Icq

command

(V293)

Flux

reference

(V305)

Logic Status Bit (V258)

(Running)

Speed

Feedback

(V289)

ISQ

Command

(V292)

Command

(V294)

Torque

Reference

(V291)

Speed Control

1557-UM050F-EN-P – June 2013

DESCRIPTION OF OPERATION 5-11

Flux Control

The function of the flux control block is to determine the magnetizing current command. The inputs are flux feedback and stator frequency from the motor model, speed feedback from the speed control block, and line voltage from the current control block.

Below base speed, the flux command varies linearly with Torque Reference from the value specified by parameter Flux Command No Load at zero torque to the value specified by parameter Flux Command Base Speed at rated torque. Above base speed, the drive goes into field weakening and the flux command decreases with increasing speed. The flux command also decreases when the current regulator approaches advance limit or retard limit.

The flux reference is determined by adding parameter Flux Reference Step, which is used to demonstrate the step response of the flux regulator, to the flux command. The flux feedback is subtracted from the flux reference to determine the flux error, which is the input to the flux regulator. The response of the flux regulator is determined by parameters Flux Regulator Bandwidth, Magnetizing Inductance, and Rotor Time Constant. The output of the flux regulator is called Isd Command 1. An open loop estimate of the magnetizing current called Isd Command 0 is determined by dividing the flux reference by parameter Magnetizing Inductance. Isd Command 0 and Isd Command 1 are added to produce Isd Command, which is the magnetizing component of the stator current command.

An estimate of the magnetizing current supplied by the motor filter capacitor is calculated from Isd Command, stator frequency, and parameters Total Leakage Inductance and Filter Capacitor. The resulting value is called Icd Command and is subtracted from Isd Command to determine Ix Command, which is the magnetizing component of the dc link current command. Ix Command becomes negative at high speed because the motor filter capacitor supplies more magnetizing current than the motor requires.

1557-UM050F-EN-P –June 2013

5-12 DESCRIPTION OF OPERATION

V line

(V324)

Speed feedback

(V289)

Base Speed

(P98)

Lm+2Ls'

Flx ref

step

(P102)

L magnetizing

(P131)

Isd command 0 (V308)

Isd

command 1

(V309)

Flux

reference

(V305)

Logic status

bit 1 (V258)

(Running)

Isd

command

(V310)

1.0

-1.0

Flx cmd

base spd

(P100)

Flx cmd

no load

(P103)

Torque

reference

(V291)

Flux

feedback

(V306)

FLUX COMMAND

PROGRAMMING

FLUX

LIMITING

Flux error

(V307)

FLUX

REGULATOR

Flxreg

bandwidth

(P97)

L magnetizing

(P131)

T rotor

(P132)

EXCITATION

CURRENT

LIMITING

L total

leakage

(P130)

Icd

command

(V311)

Command

(V312)

Filter

capacitor

(P133)

Flux Control

1557-UM050F-EN-P – June 2013

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