Woodward SG 2D User manual

37132B
SG 2D
Speed Governor
Operation Manual
Software Version 3.3xx
Manual 37132B

Operation Manual 37132B SG 2D - Speed Governor
WARNING
Read this entire manual and all other publications pertaining to the work to be performed before install-
ing, operating, or servicing this equipment. Practice all plant and safety procedures and precautions.
Failure to follow safety procedures and precautions may result in personal injury and/or property dam-
age.
The engine, turbine, or other type of prime mover should be equipped with an overspeed (overtempera-
ture, or overpressure, where applicable) shutdown device(s) that operates independently of the prime
mover control device(s) to protect against runaway or damage to the engine, turbine, or other type of
prime mover resulting in possible personal injury or loss of life should the mechanical-hydraulic gov-
ernor(s) or electric control(s), the actuator(s), fuel control(s), the driving mechanism(s), the linkage(s),
or the control device(s) fail.
CAUTION
To prevent damage to control systems that uses an alternator or battery-charging device, ensure the
charging device is turned off before disconnecting the battery source from the system.
Electronic controls contain static-sensitive parts. Observe the following precautions to prevent dam-
age to these parts.
•Discharge body static before handling the control (with power to the control turned off, contact a
grounded surface and maintain contact while handling the control).
•Avoid all plastic, vinyl, and Styrofoam (except antistatic versions) around printed circuit boards.
•Do not touch components or conductors of a printed circuit board with bare hands or conductive
devices.
Important definitions
WARNING
Indicates a potentially hazardous situation that, if not avoided, could result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation that, if not avoided, could result in damage to equipment.
NOTE
Provides other helpful information that does not fall under the warning or caution categories.
Woodward Governor Company reserves the right to update any portion of this publication at any time. Information provided by Wood-
ward Governor Company is believed to be correct and reliable. However, Woodward Governor Company assumes no responsibility
unless otherwise expressly undertaken.
© Woodward Governor Company
All Rights Reserved.
Page 2/45 © Woodward

Operation Manual 37132B SG 2D - Speed Governor
Revision History
Rev. Date Editor Change
NEW 03-01-20 Tr Release
A 05-07-28 TP New format, minor corrections, inactive units deleted
B 06-01-24 TP Minor corrections; parameter description and list updated; communication settings and wire size conversion
chart added
Content
CHAPTER 1. GENERAL INFORMATION..........................................................................................6
Introduction .............................................................................................................................................6
CHAPTER 2. ELECTROSTATIC DISCHARGE AWARENESS..............................................................7
CHAPTER 3. CONNECTION OF THE UNIT ......................................................................................8
Wiring Diagrams......................................................................................................................................8
SG 2D-T-LOV ...............................................................................................................................8
SG 2D-T-HO / HOV ......................................................................................................................9
Power Supply ........................................................................................................................................10
MPU Input .............................................................................................................................................11
Discrete Inputs ......................................................................................................................................12
Analog Input ..........................................................................................................................................12
Alarm Outputs .......................................................................................................................................12
Controller Output...................................................................................................................................13
Interface ................................................................................................................................................13
CHAPTER 4. FUNCTIONAL DESCRIPTION ...................................................................................14
Introduction ...........................................................................................................................................14
Set Point Value Specification................................................................................................................14
Speed Measurement.............................................................................................................................14
Control Variable Output ........................................................................................................................15
Actuator Current Restriction (only SG 2D-T-HO and SG 2D-T-HOV)..................................................... 15
Actuator Current Short-Cut Protection (only SG 2D-T-HO and SG 2D-T-HOV) .....................................15
Control Outputs .....................................................................................................................................16
Wire Break Monitoring ..........................................................................................................................16
Operation Sequence .............................................................................................................................17
Droop.....................................................................................................................................................18
Controller Settings.................................................................................................................................18
Procedure for Determining PID Settings ....................................................................................19
CHAPTER 5. LEDS AND INTERFACES ........................................................................................21
LEDs......................................................................................................................................................21
Seven-Segment Display .......................................................................................................................21
Push Buttons.........................................................................................................................................22
Interfaces ..............................................................................................................................................22
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Operation Manual 37132B SG 2D - Speed Governor
Page 4/45 © Woodward
CHAPTER 6. CONFIGURATION .................................................................................................. 23
Version Parameter................................................................................................................................ 24
Dynamics Parameter ............................................................................................................................ 24
Controller Parameters [Dynamics Set 1].................................................................................... 24
Controller Parameters [Dynamics Set 2].................................................................................... 25
General Parameters ................................................................................................................... 25
Engine Parameters............................................................................................................................... 27
System Parameters .............................................................................................................................. 29
Output Parameters ............................................................................................................................... 30
CHAPTER 7. COMMISSIONING................................................................................................... 31
Configuration and Connection.............................................................................................................. 31
Commissioning the SG 2D for the First Time....................................................................................... 32
APPENDIX A. DIMENSIONS ....................................................................................................... 36
APPENDIX B. TECHNICAL DATA ............................................................................................... 37
APPENDIX C. PARAMETER LIST................................................................................................ 39
APPENDIX D. SERVICE OPTIONS .............................................................................................. 40
Product Service Options....................................................................................................................... 40
Returning Equipment For Repair.......................................................................................................... 40
Packing A Control....................................................................................................................... 41
Return Authorization Number RAN ............................................................................................ 41
Replacement Parts ............................................................................................................................... 41
How To Contact Woodward.................................................................................................................. 42
Engineering Services............................................................................................................................ 43
Technical Assistance............................................................................................................................ 44

Operation Manual 37132B SG 2D - Speed Governor
Figures and Tables
Figures
Figure 3-1: Wiring diagram SG 2D-T-LOV ..............................................................................................................................8
Figure 3-2: Wiring diagram SG 2D-T-HO / HOV.....................................................................................................................9
Figure 3-3: Power supply.........................................................................................................................................................10
Figure 3-4: MPU......................................................................................................................................................................11
Figure 3-5: MPU - Minimum necessary input voltage depending on frequency .....................................................................11
Figure 3-6: Discrete inputs.......................................................................................................................................................12
Figure 3-7: Analog input - Set point specification...................................................................................................................12
Figure 3-8: Transistor outputs - SG 2D-T................................................................................................................................12
Figure 3-9: Actuator control ....................................................................................................................................................13
Figure 4-1: Actuator current restriction ...................................................................................................................................15
Figure 4-2: Control loop ..........................................................................................................................................................18
Figure 4-3: Step response (example)........................................................................................................................................18
Figure 4-4: Step response - controller setting ..........................................................................................................................20
Figure 7-1: Dimensions............................................................................................................................................................36
Tables
Table 3-1: Conversion chart - wire size...................................................................................................................................10
Table 3-2: Power supply..........................................................................................................................................................10
Table 3-3: MPU.......................................................................................................................................................................11
Table 3-4: MPU - minimum input voltage...............................................................................................................................11
Table 3-5: Discrete inputs - positive logic...............................................................................................................................12
Table 3-6: Analog input - Set point specification ....................................................................................................................12
Table 3-7: Transistor outputs - SG 2D-T.................................................................................................................................12
Table 3-8: Actuator control......................................................................................................................................................13
Table 4-1: Operation sequence ................................................................................................................................................17
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Operation Manual 37132B SG 2D - Speed Governor
Chapter 1.
General Information
Introduction
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The SG 2D is a universal digital speed governor for combustion engines, which is able to control an actuator via
PWM or analog signal. The set point value may be specified with various methods. The actual speed will be
measured via an MPU input, which may either be switching or inductive. The actuator will be controlled accord-
ingly depending on the actual and target values.
The SG 2D is available in various versions. The designation is as follows:
SG 2D-T-HOVS
Mounting [S]..Vibration dampers
[M]..DIN rail mounting
Set point value specification
[ ]..Set point via 20 mA and discrete inputs
[V].. Set point via +/-3 Vdc and discrete inputs
Controller output [LO]..Analog signal, 45 mA continuous, 85 mA peak
[HO]..PWM signal, 7 A continuous, 11 A peak
Alarm outputs and power supply
[T]..Transistor outputs, 12/24 Vdc power supply
Typ
Examples: see below
Intended Use The unit must only be operated in the manner described by this manual. The prerequisite for a
proper and safe operation of the product is correct transportation, storage, and installation as well as careful op-
eration and maintenance.
NOTE
This manual has been developed for a unit fitted with all available options. Inputs/outputs, functions,
configuration screens, and other details described, which do not exist on your unit, may be ignored.
The present manual has been prepared to enable the installation and commissioning of the unit. Due
to the large variety of parameter settings, it is not possible to cover every combination. The manual is
therefore only a guide. In case of incorrect entries or a total loss of functions, the default settings may
be taken from the list of parameters at the end of this manual.
This manual includes the following versions:
No. Type PWM
[continuous] PWM [peak] Power supply Analog set point specification Control outputs
/1 SG 2D- T-LOV 45 mA 85 mA 12/24 Vdc +/-3 Vdc Transistor
/2 T-HO 7 A 11 A 12/24 Vdc 0/4 to 20 mA Transistor
/3 T-HOV 7 A 11 A 12/24 Vdc +/-3 Vdc Transistor
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Operation Manual 37132B SG 2D - Speed Governor
Chapter 2.
Electrostatic Discharge Awareness
All electronic equipment is static-sensitive, some components more than others. To protect these components
from static damage, you must take special precautions to minimize or eliminate electrostatic discharges.
Follow these precautions when working with or near the control.
1. Before doing maintenance on the electronic control, discharge the static electricity on your body to
ground by touching and holding a grounded metal object (pipes, cabinets, equipment, etc.).
2. Avoid the build-up of static electricity on your body by not wearing clothing made of synthetic materials.
Wear cotton or cotton-blend materials as much as possible because these do not store static electric char-
ges as easily as synthetics.
3. Keep plastic, vinyl, and Styrofoam materials (such as plastic or Styrofoam cups, cigarette packages, cello-
phane wrappers, vinyl books or folders, plastic bottles, etc.) away from the control, modules, and work
area as much as possible.
4. Opening the control cover may void the unit warranty.
Do not remove the printed circuit board (PCB) from the control cabinet unless absolutely necessary. If
you must remove the PCB from the control cabinet, follow these precautions:
•Ensure that the device is completely voltage-free (all connectors have to be disconnected).
•Do not touch any part of the PCB except the edges.
•Do not touch the electrical conductors, connectors, or components with conductive devices or with
bare hands.
•When replacing a PCB, keep the new PCB in the plastic antistatic protective bag it comes in until you
are ready to install it. Immediately after removing the old PCB from the control cabinet, place it in the
antistatic protective bag.
CAUTION
To prevent damage to electronic components caused by improper handling, read and observe the pre-
cautions in Woodward manual 82715, Guide for Handling and Protection of Electronic Controls, Printed
Circuit Boards, and Modules.
© Woodward Seite 7/45

Operation Manual 37132B SG 2D - Speed Governor
Chapter 3.
Connection of the Unit
Wiring Diagrams
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SG 2D-T-LOV
2004-11-11 | SG 2D-T Wiring Diagram sg2dww-4604-ap.skf
18
-
+
+
-
+
-
17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Subject to technical modifications.
lower
Mounting
Pickup
Power supply
Digital setpoint
Droop
Common
Transistor output 2
Transistor output 1
Configuration interface
Telephone socket; connection by provided
cable to the RS-232 interface of the PC.
S..Virbration absorber M..Snap-on rail installation
raise
SG 2D-T-LOV
n[1/min]
P
I
D
SET
n
7
6[s]
5[s]
4
SET
8
9
[%/s]
[%]Start
[no.]
(0 [%])
SG2-T-LOV
1
1
Actuator (PWM signal)
Input
+/-3 V DC
910 11 12 13 14 15 16 17 18
1 2 3 4 5 6 7 8
RS232
Order notes (e.g.)
SG 2D-T-LOVM, SG 2D-T-LOVS
(0 V DC)
(+/-3 V DC)
+
-
Figure 3-1: Wiring diagram SG 2D-T-LOV
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Operation Manual 37132B SG 2D - Speed Governor
SG 2D-T-HO / HOV
2004-11-11 | SG 2D-T Wiring Diagram sg2dww-4604-ap.skf
18
-
+
+
-
+
-
17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Subject to technical modifications.
lower
Mounting
Pickup
Power supply
Digital setpoint
Droop
Common
Transistor output 2
Transistor output 1
Configuration interface
Telephone socket; connection by provided
cable to the RS-232 interface of the PC.
S..Virbration absorber M..Snap-on rail installation
raise
SG 2D-T-HOx
n[1/min]
P
I
D
SET
n
7
6[s]
5[s]
4
SET
8
9
[%/s]
[%]
Start
[no.]
(0 [%])
Ersatz
eserr va SpareusivelFpart
Rechange
[A]I max 3
SG2D-T-HO
Actuator (PWM signal)
Input
0/4 to 20 mA
RS232
910 11 12 13 14 15 16 17 18
1 2 3 4 5 6 7 8
Order notes (e.g.)
SG 2D-T-HOM, SG 2D-T-HOS
(OUT)
(IN)
+
-
+
-
+
-
+
-
+
-
+
-
2004-11-11 | SG 2D-T Wiring Diagram sg2dww-4604-ap.skf
18
(0 V DC)
(+/-3 V DC)
-
+
+
-
+
-
17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Subject to technical modifications.
lower
Mounting
Pickup
Power supply
Digital setpoint
Droop
Common
Transistor output 2
Transistor output 1
Configuration interface
Telephone socket; connection by provided
cable to the RS-232 interface of the PC.
S..Virbration absorber M..Snap-on rail installation
raise
SG 2D-T-HOV
n[1/min]
P
I
D
SET
n
7
6[s]
5[s]
4
SET
8
9
[%/s]
[%]
Start
[no.]
(0 [%])
Ersatz
eserr va SpareusivelFpart
Rechange
[A]I max 3
SG2D-T-HOV
Actuator (PWM signal)
Input
+/-3 V DC
RS232
910 11 12 13 14 15 16 17 18
1 2 3 4 5 6 7 8
Order notes (e.g.)
SG 2D-T-HOVM, SG 2D-T-HOVS
+
-
Figure 3-2: Wiring diagram SG 2D-T-HO / HOV
© Woodward Seite 9/45

Operation Manual 37132B SG 2D - Speed Governor
WARNING
A circuit breaker must be provided near the engine and in a position easily accessible for the operator.
This must also bear a sign identifying it as an isolating switch for the engine.
NOTE
Connected inductors (e.g. operating current coils or undervoltage trips, auxiliary or power contactors)
must include a suitable interference suppressor in their circuit.
The following chart may be used to convert square millimeters [mm²] to AWG and vice versa:
AWG mm² AWG mm² AWG mm² AWG mm² AWG mm² AWG mm²
30 0.05 21 0.38 14 2.5 4 25 3/0 95 600MCM 300
28 0.08 20 0.5 12 4 2 35 4/0 120 750MCM 400
26 0.14 18 0.75 10 6 1 50 300MCM 150 1000MCM 500
24 0.25 17 1.0 8 10 1/0 55 350MCM 185
22 0.34 16 1.5 6 16 2/0 70 500MCM 240
Table 3-1: Conversion chart - wire size
Power Supply
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Power supply
4 3
0 V
8 to 32 Vdc
8 to 32 Vdc
Figure 3-3: Power supply
Terminal Description Amax
3 0 Vdc reference potential 2.5 mm²
4 8 to 32 Vdc (rated voltage range 12/24 Vdc) 2.5 mm²
Table 3-2: Power supply
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Operation Manual 37132B SG 2D - Speed Governor
MPU Input
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24 V Pickup
< 1.0 V
12 -
+
Figure 3-4: MPU
Terminal Description Amax
2 switching/inductive 2.5 mm²
1 MPU GND 2.5 mm²
Table 3-3: MPU
Specification of the input circuit for inductive speed sensors
Ambient temperature: 25 °C
Signal form sinusoidal
Minimum input voltage from 200 to 10,000 Hz < 0.5 Veff
Minimum input voltage from 300 to 5,000 Hz < 0.3 Veff
Table 3-4: MPU - minimum input voltage
NOTE
As the ambient temperature increases, the minimum input voltage increases at a rate of approxi-
mately 0.3 V/°C.
Eingangsspannung in Abhängigkeit der Frequenz
0
0,5
1
1,5
2
2,5
3
100 1000 10000 100000
Frequenz [Hz]
Effektive Eingangsspannung [V]
Figure 3-5: MPU - Minimum necessary input voltage depending on frequency
© Woodward Seite 11/45

Operation Manual 37132B SG 2D - Speed Governor
Discrete Inputs
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CAUTION
Please note that the maximum voltages, which can be applied to the discrete inputs, are defined as fol-
lows. Higher voltages than this destroy the units!
Maximum input range: 4 to 40 Vdc.
24 V DC
Signal device
Digital input
AB
Figure 3-6: Discrete inputs
Terminal Associated
common Description
(in compliance with DIN 40 719 part 3, 5.8.3) Amax
A B
9 Set point lower 2.5 mm²
10 Set point raise 2.5 mm²
11 12 Droop 2.5 mm²
Table 3-5: Discrete inputs - positive logic
Analog Input
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
78
+
-
Analog input
20 mA
Figure 3-7: Analog input - Set point specification
Terminal Description Amax
7 20 mA-analog input for set point specification 2.5 mm²
8 0 mA 2.5 mm²
Table 3-6: Analog input - Set point specification
Alarm Outputs
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
NPN-transistor output
external device
DEF
Figure 3-8: Transistor outputs - SG 2D-T
Description Amax
Transistor
Collector Emitter N.C.
D E F
13 14 Transistor 1 2.5 mm²
16 17 Transistor 2 2.5 mm²
Table 3-7: Transistor outputs - SG 2D-T
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Operation Manual 37132B SG 2D - Speed Governor
Controller Output
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NOTE
The maximum current may must not be exceeded in any operating state. The rated current is decisive
for continuous operation. Refer to chapter Technical Dat starting page 37 for detailed information.
If actuators with a higher current consumption are used, the actuator's upper limit (starting state and
initial state) must be set using the LeoPC1 configuration software in that way that the maximum actua-
tor current is not exceeded. Take into account the current consumption of the actuator when it is cold.
This current flows at nominal power directly after starting and immediate operation of the engine. If the
unit is being operated at rated output and the actuator has reached its operating temperature, the
SG 2D has to be operated at no more than rated actuator current.
The definition of the upper limit in terms of control engineering is not considered here. It may also be
below the above limit.
SG 2D-T-HO / SG 2D-T-HOV: Both the SG 2D-T-HO and the SG 2D-T-HOV have an adjustable current re-
striction, which permits a continuous current of 7 A and higher for a short time. Actuators with a con-
tinuous load less than this value can be operated.
Actuator
56
-
+
Figure 3-9: Actuator control
Terminal Description Amax
5 2.5 mm²
6 Actuator control 2.5 mm²
Table 3-8: Actuator control
Interface
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NOTE
To carry out configuration via the side plug (direct configuration), a direct configuration cable (order
code "DPC" P/N: 5417-557) is required, the LeoPC1 program (supplied with the cable) and the corre-
sponding configuration files. Please consult the online help when the program is installed for a de-
scription of the LeoPC1 PC program and its setup.
© Woodward Seite 13/45

Operation Manual 37132B SG 2D - Speed Governor
Chapter 4.
Functional Description
Introduction
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
The SG 2D is an engine speed governor used to control a fuel feed actuator on an internal combustion engine.
The SG 2D can operate both as a standalone frequency controller and as a subordinate controller in conjunction
with a superordinate controller, such as a synchronizer or load control. Control is provided by a PID control al-
gorithm where the P, I and D components can be adjusted separately.
Set Point Value Specification
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
Depending on the choice of operating mode (standalone or subordinate controller), the speed reference of the
control is determined by one of three means. When operating in stand alone mode, the speed reference is deter-
mined by the Fixed set point value setting. A variable speed reference is used when working as a subordinate
controller. The SG 2D will adjust the speed reference based on the analog input or via the raise/lower digital in-
puts.
The set point value is stored in a non-volatile memory (FRAM) for operation as a standalone controller. Where
the SG 2D operates as a subordinate controller, the superordinate control unit specifies the set point value. If the
digital set point value specification is selected, the starting value is always the configured fixed set point value.
The analog input for specifying the set point value is alternatively a 0/4 to 20 mA or a +/-3 Vdc input.
There is one digital input for RAISE and one for LOWER for the set point value specification.
The DROOP digital input activates droop behavior on the controller. The droop characteristics can be configured
with the LeoPC1 software.
Speed Measurement
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
The actual speed is measured by a Pickup input; switching or inductive Pickups may be used for this.
Depending on the value of the rated speed, the minimum measurable speed is within a measuring range of 6 to
12 % of the rated speed. The maximum measurable speed also depends on the value of the rated speed and is
within a measuring range of 133 to 266 %.
Page 14/45 © Woodward

Operation Manual 37132B SG 2D - Speed Governor
Control Variable Output
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
NOTE
The actuator must have a mechanical resetting.
The governor's control variable is output by the actuator output. A pulse width modulated (PWM) output signal
generated by the microprocessor is issued to a power transistor. This activates the negative terminal of the actua-
tor. A pulse width modulated control voltage is thus generated as the control variable for the actuator.
The output signals depend on the utilized type:
© Woodward Seite 15/45
No. Type PWM
[continuous] PWM [peak] Power supply Analog set point specification Control outputs
/1 SG 2D
-
T-LOV 45 mA 85 mA 12/24 Vdc +/-3 Vdc Transistor
/2 T-HO 7 A 11 A 12/24 Vdc 0/4 to 20 mA Transistor
/3 T-HOV 7 A 11 A 12/24 Vdc +/-3 Vdc Transistor
Actuator Current Restriction (only SG 2D-T-HO and SG 2D-T-HOV)
The SG 2D continually monitors the current flowing through the actuator. If this actuator current is higher than
the adjusted limit value, an internal counter will be raised by a rate proportional to the overcurrent. If the actuator
current is below this limit value, the counter will be dropped by a proportional rate. If the counter passes over a
certain value, the actuator signal will be halved for minimum 10 ms and maximum 40 ms. If the actuator current
increases nevertheless, the signal will be stopped.
By summarizing the actual actuator current the SG 2D permits an overcurrent for an appointed time. The over-
current has to be compensated by a corresponding negative current deviation.
If there is a permanent overcurrent the SG 2D will try, after the restriction has tripped, to keep the current on the
rated limit value.
Figure 4-1: Actuator current restriction
Actuator Current Short-Cut Protection (only SG 2D-T-HO and SG 2D-T-HOV)
The SG 2D continually monitors the actuator current. If this value is larger than the allowed maximum actuator
current (peak value, see technical data), the actuator signal is stopped immediately for minimum 20 ms and
maximum 40 ms.

Operation Manual 37132B SG 2D - Speed Governor
Page 16/45 © Woodward
Control Outputs
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The SG 2D-T speed governors provide 2 transistor outputs, output 1 and output 2.
Output 1 is always configured as N.C. output, and output 2 is always configured as N.O. output. However, it is
possible to change the output logic in the configuration.
Combination 1: (Parameter: Output logic 1 "YES")
Output 1: Ready for operation relay; energized, if processor is operating.
Output 2: Overspeeed protection; the overspeed threshold may be configured.
Combination 2: (Parameter: Output logic 1 "NO")
Output 1: Ready for operation relay with superimposed overspeed protection
(tripping is combined with a logical OR)
Output 2: freely configurable, speed-dependent thresholds.
Wire Break Monitoring
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
Open circuit detection is implemented for an analog set point value specification above 4 to 20 mA. An open cir-
cuit is detected if the measured value falls below 2 mA. The set point value configured for 4 mA will be ap-
proached.

Operation Manual 37132B SG 2D - Speed Governor
Operation Sequence
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The start-up sequence of the engine can be divided into four sections according to the speed:
Condition Effect
The speed is lower than the configured switch-on speed for the
starting state. No control variable output (STOP operating condition).
The speed has reached the Minimal Speed for Start-up. Output of the actuator's starting state (configured starting state) with
subsequently adjustable increase in the starting state.
The speed is higher than the Minimal Speed for Governor
switch-on. Control mode is activated: The controller starts at the "set point value for controller switch-on". This set point value then increases in relation
to the "set point value ramp at start-up" up to the actual set point value.
The set point value has reached the fixed set point value or the
corresponding adjustable set point value set by the analog input. Transition to controller mode.
Table 4-1: Operation sequence
Rated speed
Min. speed for
gv. switch-on
Min. start speed
0 rpm
Time [s]
Engine
speed
[rpm]
3
5
6
Time [s]
Actuator
position
[%]
12
4
20
10
0
1Engine cranks and speed becomes higher than the minimum start speed; actuator opens to starting state of
the actuator setting.
2The actuator will open further according to the ramp of starting state setting.
3Engine starts and begins to accelerate.
4Engine speed reaches the minimum speed for governor switch-on, the speed control PID takes over and
will adjust the actuator as needed to control the engine speed at the speed set point.
5The engine speed is ramped at the set point ramp during start-up.
6The engine speed reaches its rated speed set point and is controlled at that speed.
The transition to the STOP operating condition from any phase is only possible if the switch-on speed again falls
below that required for the starting state. If the switch-on speed for the starting state has been configured below
the minimum measurable speed (< 12.5 %), transition will occur as soon as engine rotation is detected. If a
higher switch-on threshold is configured, a start signal will be issued once the switch-on speed has been reached.
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Operation Manual 37132B SG 2D - Speed Governor
Droop
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The controller can be switched to droop behavior; the slope of the droop characteristic curve can be modified by
means of the Droop Characteristic parameter. Droop deals with the fact that the set point value at any given time
is affected as a function of the actuator setting (which can be equated with the power output). This means that the
speed set point value is reduced as the power output of the unit increases.
If, for example, 3 % is specified as the droop characteristic curve (values between 3 % and 8 % are common), the
speed set value is reduced by approximately 1.5 % if the actuator setting has increased by 50 %. In the inverse
situation the speed increases similarly as the load on the engine is reduced.
This characteristic is very beneficial to operation in parallel with the mains or isolated operation in parallel with
other gensets. A stable operating point can now be set to the mains or another generator. The controller can thus
be operated in PID control algorithm mode at any time. The droop behavior is commonly activated by feedback
from the power circuit breakers.
Controller Settings
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The analog PID controller forms a closed-loop control loop together with the controlled system (usually a first-
order lag element). The parameters of the PID controller (proportional-action coefficient KPR, derivative-action
time TVand reset time Tn) can be adjusted individually.
Kp T1
Controlled system (PT1)PID controller
Kpr Tn Tv
Lag element (Tt)
Influenciny
quantity Tt
Figure 4-2: Control loop
If an abrupt disturbance variable is applied to the control loop, the reaction of the controlled system can be re-
corded at the output as a function of time (step response).
0
t/s
x
T
T
1
0
T
x
x
d
m
x
d
x
m
T
Rise time
Overshoot
System deviation
rise
rise
Tolerance band
Settling time
sett
sett
Figure 4-3: Step response (example)
Various values can be obtained from the step response; these are required for adjusting the controller to its opti-
mum setting:
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Operation Manual 37132B SG 2D - Speed Governor
Rise time Trise: Period starting when the value of the controlled variable leaves a predefined tolerance range for
the control variable following a step in the disturbance variable or reference input variable and ending the first
time the value re-enters this range.
Settling time Tsett:Period starting when the value of the control variable leaves a predefined tolerance range for
the control variable following a step in the influencing quantity or reference input variable and ending when the
value re-enters this range permanently.
Overshoot xm:Highest transient set point value deviation during the transition from one steady-state condition to
a new steady-state condition following modification of the disturbance variable or reference input variable (xm op-
timum ≤10 %).
System deviation xd:Permanent deviation from the final value (PID controller: xd= 0).
The values KPR, Tnand TVcan be determined from these values by applying various conversion factors. It is also
possible to determine the optimum controller setting by performing various calculations, such as compensation or
adaptation of the time constant, the T-sum Rule, Symmetrical Optimum, Bode diagram. Other setting procedures
and information may be obtained from current literature.
Procedure for Determining PID Settings
CAUTION
The following must be observed regarding the controller setting:
• Ensure that the emergency shut-down system is ready for use.
• Note the amplitude and frequency during the determination of the critical frequency.
• If the two values alter uncontrollably:
ÎEMERGENCY SHUTDOWN Í
The procedure described below only serves as an example. Whether this method is suitable for setting a particu-
lar controlled system has not been and cannot be taken into account as each controlled system behaves uniquely.
There are various methods of setting a controller. The rules according to the Ziegler and Nichols method are ex-
plained below (determination for abrupt disturbances on the system input); this method assumes a pure lag ele-
ment connected in series with a first-order lag system.
© Woodward Seite 19/45

Operation Manual 37132B SG 2D - Speed Governor
1. Controller operated as a P-only controller
(where Tn= ∞[screen setting: Tn=0], TV= 0).
2. Increase gain KPR (P-gain) until the control loop oscillates continuously at KP = KPcrit.
CAUTION
If the unit starts to oscillate uncontrollably (see the Incorrect controller setting in the following figure),
carry out an emergency shut-down and alter the KPR setting accordingly.
3. At the same time: measure the critical cycle duration Tcrit (in seconds) of the continuous oscillation.
4. Set the parameters:
PID Controller PI Controller
K
PR = 0.6 ×KPcrit KPR = 0.45 ×KPcrit
T
n= 0.5 ×Tcrit Tn= 0.83 ×Tcrit
T
V= 0.125 ×Tcrit
Step response
Controller setting Controller setting
Controller setting wrong
Tcrit
Optimum (xm≤10 %)
0
1
x
0
t/s
0
1
x
0
t/s
0
0
1
x
t/s
Figure 4-4: Step response - controller setting
P gain (KPR) Proportional-action coefficient 1 to 240
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The proportional-action coefficient KPR indicates the closed-loop control system
gain. By increasing the gain, the response is increased to permit larger corrections
to the variable to be controlled. The farther out of tolerance the process is the lar-
ger the response action is to return the process to the tolerance band. If the gain is
configured too high, the result is excessive overshoot/undershoot of the desired
value
Reset time (Tn)0.2 to 60.0 s
The reset time Tnrepresents the I-component of the PID controller. The reset time
corrects for any offset (between set point and process variable) automatically over
time by shifting the proportioning band. Reset automatically changes the output
requirements until the process variable and the set point are the same. This parame-
ter permits the user to adjust how quickly the reset attempts to correct for any off-
set. The reset time constant must be greater than the derivative time constant. If the
reset time constant is too small, the engine will continually oscillate. If the reset
time constant is too large, the engine will take to long to settle at a steady state.
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Derivative-action time (TV)0.00 to 6.00 s
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The derivative-action time TVrepresents the D-component of the PID controller.
By increasing this parameter, the stability of the system is increased. The controller
will attempt to slow down the action of the actuator in an attempt to prevent exces-
sive overshoot or undershoot. Essentially this is the brake for the process. This por-
tion of the PID loop operates anywhere within the range of the process unlike re-
set.
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