DEIF AGC-4 MK II, AGC-4 Users guide

AGC-4 MK II, AGC-4

Option D1

Voltage, var, or cos phi regulation

DEIF A/S · Frisenborgvej 33 · DK-7800 Skive

Tel.: [phone] · Fax: [phone]

[e-mail] · www.deif.com Document no.: 4189341263B

1. Description of option

1.1 Option D1........................................................................................................................................................................................................................................3

1.2 ANSI numbers..............................................................................................................................................................................................................................3

1.3 Software version........................................................................................................................................................................................................................ 3

1.4 Parameters.....................................................................................................................................................................................................................................3

1.5 Warnings, legal information and safety.........................................................................................................................................................................3

1.5.1 Warnings and notes.......................................................................................................................................................................................................... 3

1.5.2 Factory settings...................................................................................................................................................................................................................4

1.5.3 Legal information and disclaimer.................................................................................................................................................................................4

2. Function description

2.1 Regulation type (voltage/var/cos phi).............................................................................................................................................................................5

2.1.1 Regulation type based on breaker states................................................................................................................................................................ 5

2.1.2 Regulation type based on digital inputs....................................................................................................................................................................5

2.2 AVR regulation failure............................................................................................................................................................................................................. 6

2.3 Manual AVR control..................................................................................................................................................................................................................6

2.4 Voltage-dependent cos phi/Q control (y2(x2) droop)............................................................................................................................................. 7

2.4.1 Voltage support...................................................................................................................................................................................................................7

2.4.2 Example of voltage-dependent cos phi control................................................................................................................................................... 11

2.5 Power-dependent cos phi/Q control (y2(x2) droop).............................................................................................................................................12

2.5.1 Power support...................................................................................................................................................................................................................12

2.5.2 Example of power-dependent cos phi control..................................................................................................................................................... 15

OPTION D1 4189341263B EN Page 2 of 16

1. Description of option

1.1 Option D1

Option D1 is a combined software and hardware option. The specific hardware selection depends on the required interfacing to the
automatic voltage regulator (AVR).

Functions

• Automatic regulation type selection

◦ Option T2 (Digital AVR) is required for automatic voltage regulation with DEIF's Digital AVR's DVC 310, DVC 550 and/or

Nidec's D510.

◦ Option T3 (NIDEC D550 support) is required for Nidec's Digital AVR D550.

◦ For more information, see DEIF's DVC 550 Designer's handbook.

• Voltage-dependent cos phi/Q control (y2(x2) droop)

• Power-dependent cos phi/Q control (y2(x2) droop)

1.2 ANSI numbers

Function

Voltage synchronisation matching 25, 90

Constant voltage control for stand-alone generator 90

Constant reactive power control for paralleling generator 90

Constant cos phi control for paralleling generator 90

Reactive power load sharing for paralleling with other generators 90

ANSI no.

1.3 Software version

This document is based on the AGC-4 Mk II software version 6.00 and the AGC-4 software version 4.79. Option D1 is included in
the standard AGC-4 Mk II.

1.4 Parameters

The relevant parameters are included in the function descriptions. For more information, see the Parameter list.

There are also relevant settings under Advanced Protection in the utility software.

1.5 Warnings, legal information and safety

1.5.1 Warnings and notes

Throughout this document, a number of warnings and notes with helpful user information will be presented. To ensure that these are
noticed, they will be highlighted as follows in order to separate them from the general text.

Warnings

DANGER!

Warnings indicate a potentially dangerous situation, which could result in death, personal injury or damaged equipment, if
certain guidelines are not followed.

OPTION D1 4189341263B EN Page 3 of 16

Notes

INFO

Notes provide general information, which will be helpful for the reader to bear in mind.

1.5.2 Factory settings

The Multi-line 2 unit is delivered from the factory with default settings. These are not necessarily correct for the engine/generator set.
Check all the settings before running the engine/generator set.

1.5.3 Legal information and disclaimer

DEIF takes no responsibility for installation or operation of the generator set. If there is any doubt about how to install or operate the
engine/generator controlled by the Multi-line 2 unit, the company responsible for the installation or the operation of the set must be
contacted.

INFO

The Multi-line 2 unit is not to be opened by unauthorised personnel. If opened anyway, the warranty will be lost.

Disclaimer

DEIF A/S reserves the right to change any of the contents of this document without prior notice.

The English version of this document always contains the most recent and up-to-date information about the product. DEIF does not
take responsibility for the accuracy of translations, and translations might not be updated at the same time as the English document.
If there is a discrepancy, the English version prevails.

OPTION D1 4189341263B EN Page 4 of 16

2. Function description

2.1 Regulation type (voltage/var/cos phi)

The controller uses one of the following to select the regulation type:

1. The generator breaker (GB) and mains breaker (MB) states

2. Digital inputs

2.1.1 Regulation type based on breaker states

Regulation type

Fixed voltage X X

var sharing X

Fixed cos phi X

INFO
var sharing is a mix of fixed voltage and var sharing regulation, and requires option G3 or G5. (If hardware option M12 is

selected, then option G3 is included in the standard AGC-4 Mk II.) The reactive load is shared equally between the
gensets, AND the voltage is maintained at the nominal value.

GB open GB closed, MB open GB closed, MB closed

2.1.2 Regulation type based on digital inputs

You can use digital inputs to select the regulation type. This allows the controller to use external set points, for example, from an
external potentiometer or a PLC.

Regulation type

Fixed voltage Stand-alone generator or GB opened +/-10 V DC input ~ nominal voltage +/-10 %

Fixed var Fixed reactive power 0 to 10 V DC input ~ 0 to 100 % reactive power*

Fixed cos phi Fixed cos phi -10 to 0 to 10 V DC input ~ 0.6 capacitive to 1.0 to 0.6 inductive cos phi

Comment Analogue input relationship to external set point

*Note: 0 to 100 % relates to the nominal power of the generator.

Configuring the inputs

To use a digital input to activate an external set point, configure the digital input function Ext. Voltage control, Ext. cosphi control
and/or Ext. Var control using the PC utility software (USW), as shown below.

OPTION D1 4189341263B EN Page 5 of 16

INFO

It is not necessary to configure all three functions.

CIO external set points

The external set point(s) can also come from a CIO. The regulation type is activated using M-Logic. A digital input is not required.

More information
See Option A10 for more information.

2.2 AVR regulation failure

The AVR regulation failure alarm is configured in menu 2680. When the regulation is activated but the set point cannot be reached
within the configured time, the alarm is activated. The deviation is calculated in percent.

Example

U

ACTUAL

= 400 V AC

U

NOMINAL

Difference in percent: (440 - 400) / 440 * 100

If the AVR regulation failure alarm set point is lower than 9.1 %, the alarm is activated.

= 440 V AC

= 9.1 %

INFO

Change the alarm set point to 100 % to deactivate the alarm.

2.3 Manual AVR control

More information

See Manual governor and AVR control in the Designer’s Handbook for more information.

OPTION D1 4189341263B EN Page 6 of 16

2.4 Voltage-dependent cos phi/Q control (y2(x2) droop)

1 2 3 4 5

0123412345567896789

10 10

(Unom-Uact)×100/Uact [%]

0.9 l

Power factor set point

0.6 °C

DBL

MAX

SH

SL

MIN

DBH

0.6 l

COS PHI

2.4.1 Voltage support

The voltage support function is also called Voltage-dependent cos phi/Q control (y2(x2) droop) and Droop curve 2. The function changes the cos phi or the kvar set point of the generators if the mains voltage changes beyond certain values in order to support the mains voltage. The idea is that if the mains voltage drops, the generators increase their excitation and support the mains voltage. If the mains voltage increases, the excitation of the DGs decreases in order to produce less reactive power (var).

This function is used when the generators are paralleling to the mains and running Fixed power, Mains power export or Peak
shaving. It cannot be used in island applications.

Voltage support principle

In a system that is parallel to mains, voltage-dependent cos phi control provides dynamic cos phi control, based on the mains
voltage. The purpose is to support the mains voltage locally behind a transformer by minimising the reactive current flow to the
mains.

The function is made with only one active regulator on the generator, and a variable curve defining the set point to the regulator. This
ensures that there are no hunting problems with two to three regulators in cascade.

The diagram below shows the principle. The dotted line illustrates the x-axis (voltage deviation, x2), and the vertical line (cos phi, y2)
is the y-axis. The cos phi set point is 0.90 in this example.

INFO

When the function is activated, the controller uses the actual power factor at that moment as the reference for the droop
function. The controller uses this value for as long as the function is active.

The diagram has the following zones:

Zone

1 Minimum cos phi 90 to 96 %

2 Decreasing slope 96 to 98 % Cosphi Slope low (7175)

3 Deadband voltage (cos phi = 0.9 I) 98 to 102 % Deadband low (7151) [%]

OPTION D1 4189341263B EN Page 7 of 16

Description Voltage Advanced protection, Droop curve 2

Cosphi min set (7171) [Pf]
Cosphi min dir. (7172)

Zone Description Voltage Advanced protection, Droop curve 2

Deadband high (7152) [%]

4 Increasing slope 102 to 104 % Cosphi Slope high (7176)

5 Maximum cos phi 104 to 110 %

Cosphi max set (7173) [Pf]
Cosphi max. dir (7174)

INFO

The voltage-dependent droop curve is configured in Advanced protections, Droop curve 2. If full grid code rule
compliance is required, you must add Option A10. For more information, see the Option A10 documentation.

Parameters and settings

These parameters and settings are used by the voltage support function.

Name

Contr. sett. cosphi 7052 0.9 0.1 to 1

Contr. sett. cosphi 7053 Inductive Inductive, Capacitive

Advanced protection,
Droop curve 2

Default Range Description

Deadband low (7151) 2.00 % 0 to 99.99 % Deadband low, in percentage of nominal voltage.

Deadband high (7152) 2.00 % 0 to 99.99 % Deadband high in percentage of nominal voltage.

Hysteresis low (7153) 2.1 % 0 to 99.99 %

Parameter Default Range

Hysteresis low in percentage of nominal voltage. If HYSL is
set above DBL, the hysteresis low is disabled. Hysteresis is
not shown in the principle diagram.

Hysteresis high (7154) 2.1 % 0 to 99.99 %

Cosphi min set (7171) 0.8 Pf 0 to 1 Pf

Cosphi min dir. (7172) Inductive (GEN)

Inductive (GEN),
Capacitive (GEN)*

Cosphi max set (7173) 1.00 Pf

Cosphi max dir. (7174) Inductive (GEN)

Cosphi Slope low
(7175)

Cosphi Slope high
(7176)

-0.005 %/unit -1 to 1 %/unit

0.005 %/unit -1 to 1 %/unit

Inductive (GEN),
Capacitive (GEN)*

Curve select (7181) Cosphi(X2) Cosphi(X2), Q(X2)**

Hysteresis high in percentage of nominal voltage. If HYSH is
set above DBH, the hysteresis high is disabled. Hysteresis is
not shown in the principle diagram.

Minimum output of droop handling, in combination with

7172.

Direction for minimum output of droop handling.

Maximum output of droop handling, in combination with

7174.

Direction for maximum output of droop handling.

Slope low. The setting determines the increase/decrease of
the cos phi reference per percent the actual voltage drops
below nominal voltage.

Slope high. The setting determines the increase/decrease of
the cos phi reference per percent the actual voltage rises
above nominal voltage.

For the ramp slope calculation, unit is V AC. For example, 10
%/u means 10 % increase of cos phi per volt AC deviation.

Output type for droop curve 2. Choose cos phi or reactive
power.

Curve select (7182) U U, P

Input type for curve 2. Choose U for voltage-dependent cos
phi control.

Curve enable (7183) Disable Disable, Enable Enable: The selected settings are used for droop curve 2.

OPTION D1 4189341263B EN Page 8 of 16

Advanced protection,
Droop curve 2

*Note: The settings of Cosphi min set and Cosphi max set can be reversed, meaning that the reactive power will move in the
inductive direction with increasing voltage. See Capacitative range below.

**Note: If you select reactive power control (Q(X2)) in Curve select (7181), the function is similar to Cosphi (X2).

Default Range Description

Disable: Droop curve 2 is ignored.

Deadband

The ramp has a configurable deadband that can be used with reference to the nominal voltage of the mains to deactivate the ramp
functionality. This is to have a normal operation band where a normal voltage fluctuation does not create disturbance on the mains. If
the deadband is set to 0, the deadband is removed and the ramp will be active at any time.

When the mains measurement is outside the deadband, the voltage deviation is taken into consideration and a new cos phi value is
calculated. The cos phi regulator of the generator will then adjust the cos phi and thereby change the var import/export of the plant.
The calculation is based on the fixed cos phi set point value (parameter 7052).

Hysteresis

A hysteresis can be used. The cos phi set point is kept at the drooped value as the voltage returns towards nominal until the
hysteresis is reached.

For example, for a 1 % hysteresis set point and a 0.90 cos phi set point, if the voltage drops, the cos phi set point follows the slope
to, for example, 0.82. When the voltage recovers, the cos phi set point stays at 0.82 until the voltage reaches 99 %. After that, the
cos phi set point moves back to 0.90.

INFO

To deactivate hysteresis, configure the hysteresis with a value larger than the deadband.

Slope

Two settings for the slope are available, namely the "Slope Low" (SL) and the "Slope High" (SH). The name of the settings refers to
the voltage being lower or higher than the nominal voltage (100 %). The slope is adjusted with a sign (positive or negative). The
positive sign is the leading (capacitive) range, and the negative sign is the lagging (inductive) range.

This coordinate system shows when to use a positive or negative sign.

OPTION D1 4189341263B EN Page 9 of 16

When the requirement of the voltage support is known, it can be decided whether the slope is positive or negative. This is best
illustrated with an example:

If the voltage drops compared to the nominal voltage, the generator is requested to increase the excitation and thereby the produced
kvars (in order to support the grid). If the set point (SP) is 1.00 and a deadband setting is 1 %, the cos phi set point decreases from

1.00 to 0.90 (SL setting is -0.05). See the calculation and diagram below.

SP

NEW 388 V AC

= 1.00 - (((396 - 388) / 400) * 100) × 0.05

= 0.90 (simplified)

Slope calculation example

Values used in this example:

• UNormal = 400 V

• 7052 Cosphi set point = 1

• Deadband low = 2 %

• Deadband high = 3 %

• Umax: 448 V = Cosphi 0.95C

• Umin: 376 V = Cosphi 0.95I

Slope low calculation

Delta U high = Umax - (UNormal + Deadband low) = 448 V - 408 V = 40 V
Delta U high / UNormal = 40 V / 400 V = 0.1 = 10 %
Delta Cosphi low = 1 - 0.95 = 0.05
Slope low = 0.05 / 10 % = 0.005

OPTION D1 4189341263B EN Page 10 of 16

Slope high calculation

Delta U low = Umin - (UNormal - Deadband low) = 376 V - 388 V = -12 V
Delta U low / UNormal = -12 V / 400 V = -0.03 = -3 %
Delta Cosphi high = 1 - 0.95 = 0.05
Slope high = 0.05 / -3 % = -0.017

Capacitive range

Even though the function is normally used to support a low mains voltage, it is possible to adjust the function to decrease the
excitation if the voltage increases (leading cos phi).

CAUTION

To avoid pole slip and damage of the generators, make sure that the capability curve of the generators is respected and
that the generators are not running under-excited or without excitation.

2.4.2 Example of voltage-dependent cos phi control

Parameters and settings for the example

Name

Contr. sett. cosphi 7052 0.9

Contr. sett. cosphi 7053 Inductive

OPTION D1 4189341263B EN Page 11 of 16

Parameter Settings

Advanced protection, Droop curve 2 Setting

MIN (7171 /7172)

Cos phi

0%-1%-2%-3%-4% 1% 2% 3% 4% 5%-5%

Setting 7052 /7053 value

(fixed Cos phi set point)

-6%-7%-8%-9%-10% 6% 7% 8% 9% 10%

SH (7176)

0.6 Cap

DBL

(7151)

SL (7175)

0.6 lnd

MAX 7173/71 74

HYSL

(7153)

HYSH

(7154)

DBH

(7152)

UNominal

100*U)nominal-U(A ctual

Deadband low (7151) 2.00 %

Deadband high (7152) 2.00 %

Hysteresis low (7153) 1.0 %

Hysteresis high (7154) 1.0 %

Cosphi min set (7171) 0.7 Pf

Cosphi min dir. (7172) Inductive (GEN)

Cosphi max set (7173) 0.9 Pf

Cosphi max dir. (7174) Capacitive (GEN)

Cosphi Slope low (7175) -0.1 %/unit

Cosphi Slope high (7176) 0.05 %/unit

Curve select (7181) Cosphi(X2)

Curve select (7182) U

Curve enable (7183) Enable

Scenario

With a nominal voltage of 400 V and an actual voltage of 412 V, there is a deviation of 12 V which is equal to a 3 % deviation from
the nominal setting. Based on the parameters and settings above, the genset will then droop to a cos phi of 0.95 inductive.

Voltage-dependent cos phi droop curve

INFO

The output in the exact moment the droop is launched will be frozen and used as set point for the droop actions as long as
the droop is active (shown as "fixed cos phi set point" in the diagram above).

2.5 Power-dependent cos phi/Q control (y2(x2) droop)

2.5.1 Power support

Power-dependent cos phi control gives a dynamic cos phi control in a parallel to mains system based on the generator-produced
power. The purpose is to support the mains locally behind a transformer by minimising the reactive current flow in the grid.

OPTION D1 4189341263B EN Page 12 of 16

The function measures and reacts based on the generator power measurement. The function calculates a dynamic power­dependent cos phi that is used to support the mains voltage/compensate the voltage impact of the power produced. The ramp has a
configurable deadband that can be used with reference to the nominal power of the generator to deactivate the ramp functionality.

The power support function is also called Power-dependent cos phi/Q control (y2(x2) droop) and Droop curve 2.

This function is used when the generators are paralleling to the mains and running Fixed power, Mains power export or Peak
shaving. It cannot be used in island applications.

Power support principle

In a system that is parallel to mains, power-dependent cos phi control provides dynamic cos phi control, based on the generator
power.

The function is made with only one active regulator on the generator, and a variable curve defining the set point to the regulator. This
ensures that there are no hunting problems with two to three regulators in cascade.

The principle is shown in by a diagram in the example. The horizontal x-axis is for the power deviation, x2, and the vertical y-axis is
for cos phi, y2.

INFO

When the function is activated, the controller uses the actual power factor at that moment as the reference for the droop
function. The controller uses this value for as long as the function is active.

INFO

The power-dependent droop curve is configured in Advanced protections, Droop curve 2. If full grid code rule
compliance is required, you must add Option A10. For more information, see the Option A10 documentation.

Parameters and settings

These parameters and settings are used by the power support function.

Name

Contr. sett. cosphi 7052 0.9 0.1 to 1

Contr. sett. cosphi 7053 Inductive Inductive, Capacitive

Advanced protection,
Droop curve 2

Deadband low (7151) 2.00 % 0 to 99.99 % Deadband low, in percentage of genset nominal power.

Deadband high (7152) 2.00 % 0 to 99.99 %

Hysteresis low (7153) 2.1 % 0 to 99.99 %

Default Range Description

Parameter Default Range

Deadband high in percentage of genset nominal power.

This should be high, to deactivate the droop when the actual
generator power exceeds the nominal power.

Hysteresis low in percentage of nominal power. If HYSL is
set above DBL, the hysteresis low is disabled.

Hysteresis high (7154) 2.1 % 0 to 99.99 %

Cosphi min set (7171) 0.8 Pf 0 to 1 Pf

Cosphi min dir. (7172) Inductive (GEN)

Cosphi max set (7173) 1.00 Pf

OPTION D1 4189341263B EN Page 13 of 16

Inductive (GEN),
Capacitive (GEN)*

Hysteresis high in percentage of nominal power. If HYSH is
set above DBH, the hysteresis high is disabled.

Minimum output of droop handling, in combination with

7172.

Direction for minimum output of droop handling.

Maximum output of droop handling, in combination with

7174.

Advanced protection,
Droop curve 2

Default Range Description

Cosphi max dir. (7174) Inductive (GEN)

Cosphi Slope low
(7175)

Cosphi Slope high
(7176)

Curve select (7181) Cosphi(X2) Cosphi(X2), Q(X2)**

Curve select (7182) U U, P

Curve enable (7183) Disable Disable, Enable

*Note: The settings of Cosphi min set and Cosphi max set can be reversed, meaning that the reactive power will move in the
inductive direction with increasing power. See Capacitative range below.

-0.005 %/unit -1 to 1 %/unit

0.005 %/unit -1 to 1 %/unit

Inductive (GEN),
Capacitive (GEN)*

Direction for maximum output of droop handling.

Slope low. The setting determines the increase/decrease of
the cos phi reference per percent the actual power drops
below nominal power.

For the ramp slope calculation, see Example of power-

dependent cos phi control.

Slope high. The setting determines the increase/decrease of
the cos phi reference per percent the actual power rises
above nominal power.

Output type for droop curve 2. Choose cos phi or reactive
power.

Input type for curve 2. Choose P for power-dependent cos

phi control.

Enable: The selected settings are used for droop curve 2.
Disable: Droop curve 2 is ignored.

**Note: If you select reactive power control (Q(X2)) in Curve select (7181), the function is similar to frequency droop (y1(x1)). See
the Designer's Reference Handbook explanation of frequency droop.

Deadband

The ramp has a configurable deadband that can be used with reference to the generator nominal power to deactivate the ramp
functionality. This is to have a normal operation band where a normal power fluctuation does not create disturbance on the mains. If
the deadband is set to 0, the deadband is removed and the ramp will be active at any time.

When the generator measurement is outside the deadband, the power deviation is taken into consideration and a new cos phi value
is calculated. The cos phi regulator of the generator will then adjust the cos phi and thereby change the var import/export of the
plant. The calculation is based on the fixed cos phi set point value.

Hysteresis

A hysteresis can be used. The cos phi set point is kept at the drooped value as the power returns towards nominal until the
hysteresis is reached.

For example, for a 1 % hysteresis set point and a 0.90 cos phi set point, if the power drops, the cos phi set point follows the slope to,
for example, 0.82. When the power recovers, the cos phi set point stays at 0.82 until the power reaches 99 %. After that, the cos phi
set point moves back to 0.90.

INFO

To deactivate hysteresis, configure the hysteresis with a value larger than the deadband.

Slope

Two settings for the slope are available, namely the "Slope Low" (SL) and the "Slope High" (SH). The name of the settings refers to
the power being lower or higher than the nominal power (100 %). The slope is adjusted with a sign (positive or negative). The
positive sign is the leading (capacitive) range, and the negative sign is the lagging (inductive) range.

See Voltage support for more details.

OPTION D1 4189341263B EN Page 14 of 16

Capacitive range

It is possible to adjust the function to decrease the excitation if the power increases (leading cos phi).

CAUTION

To avoid pole slip and damage of the generators, make sure that the capability curve of the generators is respected and
that the generators are not running under-excited or without excitation.

2.5.2 Example of power-dependent cos phi control

Parameters and settings for the example

Name Parameter Settings

Contr. sett. cosphi 7052 1.0

Contr. sett. cosphi 7053 Inductive

Advanced protection, Droop curve 2 Setting

Deadband low (7151) 0 %

Deadband high (7152) 50 %

Hysteresis low (7153) 1.0 %

Hysteresis high (7154) 51.0 %*

Cosphi min set (7171) 1.0 Pf**

Cosphi min dir. (7172) Inductive (GEN)

Cosphi max set (7173) 0.95 Pf

Cosphi max dir. (7174) Capacitive (GEN)

Cosphi Slope low (7175) 0.001 %/unit

Cosphi Slope high (7176) 0 %/unit***

Curve select (7181) Cosphi(X2)

Curve select (7182) P

Curve enable (7183) Enable

*Note: This value disables the hysteresis.

**Note: For this value, if the power increases above 100 %, the cos phi is kept at 1.0.

***Note: For this value, the cos phi is kept at the nominal cos phi when the power is above 100 %.

Slope calculation example

Cosphi Delta low = 1 - 0.95 = 0.05
Slope in % of P = 100 % - 50 % = 50 %
Slope = 0.05 / 50 % = 0.001

OPTION D1 4189341263B EN Page 15 of 16

Power-dependent cos phi droop curve

MIN (7171/

7172)

Cos phi

100%90%80%70%60 % 110% 120% 130% 140% 150%50%

Setting 7052 /7053 value

(fixed Cos phi set point)

40%30%20%10 %0% 160% 170% 180% 190% 200%

0.95 Cap

SL (7175)

MAX (P) 71 73/7174

PNominal

100*PProduced

DBL (7151)

0.98 Cap

0.98 Ind

0.95 Ind

OPTION D1 4189341263B EN Page 16 of 16