DGS-8800e
Digital Governor System, DGS-8800e
Sulzer RTA engines
Denis version
Instruction Manual
Department/Author: Approved by:
___________________ ____________________
Øyvind Tellefsen Morten Hasås
2025 KongsbergNorcontrol as
All rights reserved
No part of this work covered by the copyright
hereon may be reproduced or otherwise copied
without prior permission from
Kongsberg Norcontrol as
-Intentionally left blank-
DOCUMENT STATUS
Date/Year | Inc. by | Issue No. | Date/Year | Inc. by | |
P0 | 31-Aug-93 | GAM | |||
A | 27-Jun-94 | BGJ | |||
B | 16-Feb-98 | MOH | |||
CHANGES IN DOCUMENT
Issue | ECO | Paragraph | Paragraph Heading/ |
No. | No. | No. | Description of Change |
A | First issue | ||
B | AAE 000034 | Document updated, NSD ch. to WNSCH | |
TABLE OF CONTENTS
Section Page
1. System Description 1
1.1 Introduction 1
1.1.1 Regulator functions 2
1.1.2 Actuator Function 2
1.1.3 System configuration 3
1.2 System Units 4
1.2.1 Digital Governor Unit, DGU 4
1.2.2 Digital Servo Unit (DSU) 5
1.2.3 TRAFO 001 6
1.2.4 Electric actuator, ELACT 001 7
1.2.5 Equipment Location 8
1.3 Main Specification 8
1.3.1 Input and output data-channels 8
1.3.2 Logic input signals 8
1.3.3 Power Positioning Characteristics 9
1.4 Mode selections 10
1.4.1 NORMAL mode 10
1.4.2 IDLE mode 10
1.4.3 CONSTANT FUEL mode 10
1.4.4 ROUGH SEA mode 11
1.4.5 SETPOINT mode 11
1.4.6 TEST mode 11
1.4.7 CALIBRATION mode 11
1.4.8 SELFTEST mode 12
1.5 Programmable functions 13
1.6 Programming characteristics 14
1.7 Regulator main functions 15
1.7.1 RPM Controller Function 16
1.7.2 RPM Command Function 17
1.7.3 RPM Measurement Function 18
1.7.4 Regulator Gain Function 19
1.7.5 Fuel Limiting Function 20
1.8 Actuator Main Functions 21
1.8.1 Fuel Actuating Function 21
1.8.2 Servo Control function 21
2. System Operation 22
2.1 Regulator Operator Panel 22
2.1.1 Panel Layout 22
2.1.2 Regulator Indicator Lamps 23
2.1.3 Regulator Mode Lamps 23
2.1.4 Regulator STATUS lamps 24
2.1.5 Regulator ALARM/WARNING lamps 24
2.2 Parameter and Data Areas 25
2.2.1 Parameter Up/Down 25
2.2.2 Data value Up/Down 26
2.2.3 Change Lock 26
2.2.4 Service code 26
2.2.5 Save 26
2.3 Regulator Operating Buttons 26
2.3.1 Constant Fuel Mode Button 27
2.3.2 Rough Sea Button 27
2.3.3 Fuel Setpoint Button 28
2.3.4 Regulator Test Buttons 28
2.4 Actuator Operating Panel 30
2.4.1 Actuator Indicator Lamps 30
2.4.2 Actuator MODE lamps 30
2.4.3 Actuator STATUS lamps 30
2.4.4 Actuator ALARM lamps 31
2.4.5 Actuator Parameter and Data Areas 32
2.4.6 Actuator Operating Buttons 33
2.4.7 Actuator Test Buttons 34
2.5 Procedures 35
2.5.1 Power On 35
2.5.2 Power Off 35
2.5.3 Start Command 35
2.5.4 Transfer Command between remote control and back-up control 36
2.5.5 Stop Command 36
2.5.6 Fuel Setpoint Emergency Control 36
3. Trouble Shooting 37
3.1 Alarms / Warnings 37
3.2 Regulator Alarms 37
3.2.1 System in Test 37
3.2.2 Low Voltage Alarm 38
3.2.3 RPM Detector Failure 39
3.2.4 In-Data Error on Regulator 40
3.2.5 Out Data Error 40
3.3 Actuator Alarms 41
3.3.1 Feedback Failure 41
3.3.2 Indata Error on Actuator 41
3.3.3 Servo Amplifier Failure 42
3.3.4 System in Test on Actuator 42
3.4 Special Messages 43
3.4.1 " -- e r r o r " 43
3.4.2 " -- l o a d " 44
3.4.3 " 88 888888 " 44
3.4.4 Freeze 44
3.5 Actuator Unit 44
3.5.1 Unstable servo 44
4. Adjustments 45
4.1 START-UP 45
4.1.1 Power-Up 45
4.1.2 Adjust BASIC parameters. 46
4.1.3 Actuator zero adjustment 47
4.1.4 Fuel Output Signals (Option) 48
4.1.5 RPM detectors 48
4.2 Regulator parameter description. 49
4.2.1 Regulator parameter adjustments 49
4.2.2 Regulator input signal adjustment 49
4.2.3 Digital signals 49
4.2.4 Analog signals 49
4.2.5 OpCode 0 Parameters. 50
4.2.6 OpCode 1 Parameters. 51
4.2.7 Engine Data. 51
4.2.8 RPM Cmd Limiting 54
4.2.9 Measured RPM Filters 57
4.2.10 Speed Controller Response 58
4.2.11 Fuel Setpoint 60
4.2.12 Fuel Limiters 61
4.2.13 Actuator type setting. 62
4.2.14 Dead band mode or constant fuel mode 64
4.2.15 Various parameters. (Stop signal, Cancel limiters,,,) 66
4.2.16 Alarm Adjustments 67
4.2.17 Dual Rpm Command Instruments. Digital fuel limiter output signal. 68
4.2.18 Non Linear Compensation Due To Fuel Pump Position 69
4.2.19 Shaft Generator Function. 69
4.2.20 Non Linear Compensation Due To Low RPM 70
4.2.21 QPT 71
4.2.22 Test 71
4.3 Actuator parameter description 73
4.3.1 Mode selection. 73
4.3.2 Readable information. 73
4.3.3 Alarm info, info reset and feedback failure block reset. 73
4.3.4 System parameter. 74
4.3.5 Actuator Control Parameters. 74
4.3.6 Servo Position Feedback Fail Test. 75
4.3.7 Idle mode, manual control. 76
4.3.8 Actuator operating range. 77
4.3.9 Alarm Relay. 77
4.3.10 Digital input signals. 78
4.3.11 Block when low voltage. 78
4.3.12 Actuator rotation direction. 78
4.3.13 Fuel indication output signal. 79
4.3.14 Test parameters. 79
4.3.15 Readable parameters. 79
5. Maintenance 81
5.1 Visual Inspections 81
6. APPENDIX 83
6.1 Appendix A, Input and output signal list for DGS-8800e 83
6.2 Appendix B *** Dip-Switches 84
6.3 Appendix C *** Digital Inputs on Regulator 85
6.4 Appendix D *** Analog Inputs on Regulator 86
6.5 Appendix E *** Digital Inputs on Actuator 87
6.6 Appendix F *** Hexadecimal Counting 88
6.7 Appendix G *** Jumpers on NN-791.12 I/O Processor Board. 89
6.8 Appendix H *** Layout for NN-791.12 I/O Processor Board. 90
6.9 Appendix I *** Jumpers on NA-1105 91
6.10 Appendix J *** Back-wiring 92
7. Related Documents. 92
7.1 SBS Servo Amplifier Manual (Parvex). 92
7.2 DGS 8800e Parameter List. (KNCA, AA-0089.DOC) 92
TABLE OF FIGURES
Section Page
Figure 1.1 System configuration. 3
Figure 1.2 Digital Governor Unit DGU 8800e 4
Figure 1.3 DSU, Servo amplifier and power unit's 5
Figure 1.5 Transformer 6
Figure 1.6 Electric actuator - ELACT 001 7
Figure 1.7 DGU 8800e Block Diagram. 15
Figure 1.8 Governor functions. 16
Figure 1.9 RPM Command Function. 17
Figure 1.10 RPM Measuring Function. 18
Figure 1.11 Regulating Gain Function. 19
Figure 1.12 Fuel Limiting, Non Linear Compensation and Output Scaling Function 20
Figure 1.13 Servo Control Function 21
Figure 2.1 Operator Panel 22
Figure 2.2 Indicator lamps. 23
Figure 2.3 Regulator Parameter and Data Areas. 25
Figure 2.4 Regulator Operation Buttons. 28
Figure 2.5 Regulator Test Buttons. 29
Figure 2.6 Actuator Indication lamps. 30
Figure 2.7 Actuator Parameter and Data Areas. 32
Figure 2.8 Actuator Operation Buttons. 33
Figure 2.9 Actuator Test Buttons. 34
Figure 4.1 Rotation of actuator. (CW = Clock Wise, CCW = Counter Clock Wise). 47
Figure 4.2 Actuator Arm. 52
Figure 4.3 Critical speed. Blocked areas. 56
Figure 4.5 Constant fuel mode. 65
Figure 4.6 Non Linear compensation due to low speed. 70
Figure 4.7 Actuator position timing. 72
Figure 4.8 Actuator Gain. 74
Figure 4.9 Timeout for too slow. 76
Figure 4.10 Actuator position, 79
Figure 6.1 Dipswitches. 84
Figure 6.2 Digital inputs on regulator. 85
Figure 6.3 Analog inputs on regulator. 86
Figure 6.4 Processor board layout. 90
Figure 6.5 NA-1105, Acyncron Buffer layout. 91
1.1 Introduction
The Digital Governor System (DGS-8800e) is a complete package which fulfills all tasks for governing the speed of low-speed, long-stroke diesel engine of the Sulzer RTA type manufactured by Wärtsila NSD and their licencees. The speed setting may be from three different systems, usually the remote control system (AutoChief 4 or AutoChief 7), local control panel, and control room back-up panel (optional).
The system may be fitted to both fixed pitch and controllable pitch propeller systems (FPP and CPP systems). The system responds to slow-down and shut-down signals from external safety systems. Fuel-saving features, such as load limiting functions, are included.
The DGS 8800e performs computerized handling of all measurements and control signals. It includes panel push-button flexibility to select, adjust, and test the system performance. Movement of the fuel rack is done by an electric actuator, with a 3 phase brushless servomotor as the power medium.
The main purpose of the DGS 8800e system is to control the position of the engine fuel servo, in order to maintain an engine speed equal to a reference setting. The system is composed of two separate and self-contained subsystems, the speed Regulating Function, and the fuel Actuator Function.
The speed pick-up sensors are of an inductive type, mounted towards engine gearwheel inside the main engine. They are completely duplicated for increased system reliability.
Engine charge air pressure is measured to be able to limit the fuel injection according to charge air pressure value.
For CCP systems, the pitch value is input to compensate for loading conditions.
The speed reference input to the system may be one of three, selectable either from the remote control system (from bridge or control room), the local control panel, or the control room back-up panel.
The DSU (Digital Servo Unit) which is supplied from the AC mains, supplies the DGS 8800e system with 24V DC.
The ELACT (Electric Actuator) is supplied by a 3 phase AC main power supply through a TRAFO 001 (transformer) and the DSU with power and servo amplifier. The Actuator Feedback Transducer is a high resolution absolute encoder with contactless displacement to improve system reliability.
1.1.1 Regulator functions
The main purposes are:
Speed reference computation.
Speed measurement and filtering.
Output and limit the command signal to the fuel actuating function.
In addition, the Regulating Function has several sub-functions, such as:
Displaying data values.
Programming user-dependent parameters.
On-line testing.
Off-line testing.
Selection of alternative mode operations.
1.1.2 Actuator Function
The main purposes are:
Sense the actuator position command from the Regulator.
Positioning the actuator (and fuel-rack) according to commanded value.
In addition, the Actuating Function contains several secondary functions:
Limiting speed of fuel-rack.
Output for fuel-rack (actuator) indication (option).
Displaying data values.
Repeatedly testing of System failures.
1.1.3 System configuration
This configuration drawings shows the DGS-8800e with the belonging accessories, arrangement is in accordance with the Denis specifications issued by Wärtslia NSD (Denis-1, Denis-5 and Denis-6).
Figure 1.1 System configuration.
1.2 System Units
The DGS 8800e Digital Governor System consists of these basic units:
a) DGU 8800e Digital Governor Unit.
b) DSU, Digital Servo Unit.
e) TRAFO 001, Transformer, interface between mains and DSU.
f) ELACT 001, Electric actuator.
1.2.1 Digital Governor Unit, DGU
The DGU (Fig.1.2) fits into standard 19 inch rack. It has internal Power Module for low-voltage distribution. The panel section allows direct operator control of system functions. The signals from process are all connected to standard terminal boards, with easy flat-cable connection into the unit.
The process signals are adapted to digital data through individual plug-in adapters, with options for all standard signal formats.
Figure 1.2 Digital Governor Unit DGU 8800e
1.2.2 Digital Servo Unit (DSU)
The ABS power unit, SBS servo amplifier and 24V DC power supply for the DGU 8800e are mounted in cabinet for installation on wall in the engine control room.
The servo amplifier together with the power unit are the electric actuator's control electronic and controls the electric actuator speed.
Figure 1.3 DSU, Servo amplifier and power unit's
1.2.3 TRAFO 001
The Trafo 001 is a transformer unit that supplies the electric actuator's power amplifier with 135 V AC for speed control of the electric actuator.
The transformer has 220V AC, 230V AC or 440V AC input and 135V AC output. It is specified to deliver up to 3.6 kVA continuously. 110VAC or other input voltage transformer may be delivered on request.
1.2.4 Electric actuator, ELACT 001
The actuator system comprises a brushless servomotor type Parvex LS 620 EL, with a reduction gear type Cyclo FABS 25/89. The servomotor is electro-mechanical and contains no electronic components. It has ball bearings which are lubricated for life. The system is certified for protection degree IP65, precision class N and insulation class F. The servomotor is controlled by servo amplifier Parvex SBS 15/30A. The servomotor has a built-in brake which activates if a failure such as system failure or power failure occurs, and will keep the fuel rack at the current position, i.e. fail-safe condition, as the engine will continue to run at it's previous speed. A thermal protection device is also included in the servo motor. The fuel index (or actuator position) is measured with an absolute encoder, mounted directly on the servomotor. The fuel actuator is to be mounted and connected the fuelrack of the main engine in accordance with drawings issued by Wärtsila NSD.
Figure 1.6 Electric actuator - ELACT 001
1.2.5 Equipment Location
The DGU unit is to be located in the control room console, and should be mounted in the vertical section of the console.
The DSU cabinet is a standard wall-mountable box, which should have less than 25 m cabling distance from the actuator.
The Actuator is mounted on the engine and is connected to fuel linkage in accordance with drawings issued by Wärtsila NSD.
1.3.1 Input and output data-channels
a) Two speed inputs signal from two inductive pick-up's delivered by the engine builder, and mounted as spesified by WNSCH. One set of duplicate channel. Measures speed up to more than 300 rpm. Which handles engines from the smallest RTA48 to the largest RTA96C. Minimum frequency of approximately 4 Hz, depending of max. speed and number of pulses received from the speed pick-ups.
b) Three speed command inputs, 4-20 mA current, 0-10 V, or from 5K potentiometer.
c) One charge air pressure signal, 0-4 bar, 4-20 mA.
d) Pitch feedback signal, 5K potentiometer or -10 to +10 V (for CPP installations).
d) Two output signals, reflecting engine fuel index (load indicator). Output signal
are 4-20 mA or 0 - 10 VDC.
NOTE: These signals are a copy of the actuator position.
g) Start diesel signal (active when shaftgen. is active and speed command is
reduced). (Optional feautre)
1.3.2 Logic input signals
a) External stop (shut down) signal from external safety system.
b) Three binary (on/off) command position selection signals, selecting which of the three speed command signals that are to be used.
c) Slow-down signal from external safety system.
d) Zero fuel order from each of the three command positions (to be active when STOP, i.e. zero fuel is ordered).
e) Power-failure signal from remote control system (speedset freeze at last engine running speed).
f) Back-up RPM (for CPP installations only).
g) Heavy start (or increasing fuel limiters) from remote control system and from switch in control room.
1.3.3 Power Positioning Characteristics
Power positioning characteristics: | ELACT-001 |
Maximum output power torque (nominal) | 360 Nm |
Maximum output power torque (nominal) | 720 Nm |
Static accuracy* | 0.1 mm |
Maximum speed* | 372 mm/sec |
Stroke w/ 140 mm arm (angle 42°)* | 100 mm* |
Controllable angle | 42° |
* At operating angle 42, 140 mm. actuator arm, giving a max. stroke of 100 mm.
1.4 Mode selections
The descriptions given in the following paragraphs are valid both for Regulator and Actuator parts. The actual system mode is shown on the upper left indicator panel on front of DGU.
1.4.1 NORMAL mode
This mode indicates normal running mode of the system. The transfer to this mode is done automatically by the maneuvering handle. All adjustments of system parameters is allowed also saving (kept after powering down) is done. Monitoring of all system data values may be done by appropriate parameter number (refer commissioning parameter list).
1.4.2 IDLE mode
This mode is automatically selected after powering up system. In this condition, the actual real time processing of governor is not critical. The ultimate condition to stay in this mode, is for the that STOP is ordered (zero fuel order signal is ON).
Reprogramming of parameter values can be done.
NOTE: Automatic transfer to Idle when system is in STOP status.
1.4.3 CONSTANT FUEL mode
This mode can be selected by pressing the pushbutton “CONST.FUEL” on the front panel of the DGU. The intention with this function is to keep the fuel rack steady, the objective is to save fuel. The functions allows a greater variation of engine speed, and sets a larger deadband to the speed regulation. If the engine speed is outside the “disengage high and low” deadband, the function will be disengaged, and the governor will regulate the speed until it is inside the “engage high and low” deadband, as shown in the below drawing:
1.4.4 ROUGH SEA mode
This mode can be selected by pressing the pushbutton “ROUGH SEA” on the front panel of the DGU. In this mode, the regulator selects the Rough Sea gain-setting for PI governor, and can also include the D-function (to make it a PID and not just a PI regulator). These alternate values may be programmed to adapt more to a special sea-going condition, such as ballasted vessel, or rough sea situations
1.4.5 SETPOINT mode
This mode can be selected by pressing the pushbutton “FUEL SETP.” on the front panel of the DGU. Enabling of setpoint mode is possible to prevent with a parameter setting. However, if the setpoint mode parameter is enabled, then setpoint mode can be transferred from Normal or Idle mode. This is done by opening the Change Lock switch to open position with the key and pushing the FUEL SETPOINT button on front panel. Note, however, that this is meant to be a degraded operational mode, where the command handle outputs a fuel-index command directly. This feature allows emergency operation from a more comfortable place than local stand at the engine side. When this function is in use, there will be a SYSTEM IN TEST alarm.
NOTE: This mode has two more parameters that must be adjusted to match "RPM command" with "fuel index". Normal adjustment will be Dead Slow RPM level to match 0% fuel index and Full Seaspeed to match 100% fuel index.
1.4.6 TEST mode
The Test mode may be initiated both from on-line (from Normal mode) or off-line (from Idle mode). In this mode, the input values to the system can be set directly from front panel. The system shall respond to these settings in same manner as original values from input transducers. When this function is in use, there will be a SYSTEM IN TEST alarm.
a) Transfer from Normal mode is done by selecting one of the buttons in Test area of front panel: CMD, PITCH, or CHARGE.
NOTE: RPM button (measured RPM on engine) is not allowed, since one assume running engine condition.
b) Transfer from Idle mode is done by selecting parameter no.1, and adjust data value to 2. In this situation, also selection of RPM test button is allowed.
1.4.7 CALIBRATION mode
Calibration mode may be transferred from both Normal and Idle mode. In Normal, running mode the CAL test button starts an overlaying RPM value to the real inputted data. This "disturbance" value may be initiated in order to test governor response. Transfer from Idle mode is done by selecting parameter no.1 equal to 3. In this condition, an overlaying shifting signal adds to the value of chosen selection, either by pushing CMD-, RPM-, or CHARGE buttons.
1.4.8 SELFTEST mode
The Selftest mode can only be initiated from Idle mode condition. In this mode, the hardware memory of the computer is tested. Select parameter 1 and adjust data to 5 (light in indicator on panel). Then push the LAMP TEST button. The computer will respond with an "UP" status, or an "ERROR" status. Refer to Trouble Shooting if error status.
The DGU regulating functions are to be set up with parameter values, in accordance with each particular installation. The main programmable functions are:
a) Starting setpoints of fuel, and extension time after starting.
b) Acceleration limiting of speed commanding signal.
c) Critical speed-ranges.
d) Maximum limit of RPM command value.
e) Charge.air/index limiting characteristic.
f) Speed/index limiting characteristic. (Torque Limiter)
g) Zero-pitch/index limiting characteristic (only for CPP systems).
h) Maximum limit of index (actuator) position.
i) Regulator gain characteristics.
j) Error-band gain setting.
k) Command feed-forward influence in fuel setting.
l) Filtering of speed oscillation caused by engine firing action (Notch filter).
In addition the system includes secondary programmable functions, such as:
m) Numeric calibration of input data.
n) Activity level-definitions of all binary input signals.
o) Filtering of displayed data values.
p) Data output on analog test-channels.
q) Auto-calibration of actuator servo.
r) Delay time in alarming condition to Alarm central.
1.6 Programming characteristics
Table 1.1 illustrates the regulators main programmable functions.
Function | Characteristics | Parameters | Comments |
1. Governor Damping |
| Gain (1) Integration Factor (2) | Increasing gain may speed up system response. Increasing integration factor will increase relative stability |
2. Error-Band Suppression |
| Deadband (1) Band-Gain (2) | Band suppression mode is operator selectable. Suppresses vibration or jiggling of actuator system |
3. RPM Command Forward Coupling |
| Forward Gain (1) | Direct increase or decrease of fuel index setting, irrespective of deadband in regulator system. Makes possible direct fuel control in speed detection failure situation |
4. Low-Speed Vibratory Revolution Suppression |
| Frequency Factor (1) | The suppression filter will automatically be disconnected above maximum specified speed limit |
Table 1.1 Regulator Conditioning Functions
The DGS 8800e system consists of two separate, and modular microprocessor controlled sub-systems performing the following functions:
RPM Regulating Function.
Fuel Actuating Function.
A simplified block diagram of the DGS 8800e system is shown in Fig. 1.7.
Figure 1.7 DGU 8800e Block Diagram.
1.7.1 RPM Controller Function
The RPM reference values are automatically computed for all engine running conditions, such as start/stop, slow-down, emergency run, and normal running. The RPM measurements are converted from pulse frequency data to filtered, digital internal values.
The difference between reference and measurement is processed to ensure the optimum correction signal to the fuel setting, taking both the loading characteristics and running RPM into account.
Maximum fuel is automatically limited according to tolerances given by speed and charge air pressure.
The RPM Regulating Functions are shown in Fig. 1.8 and detailed in Fig. 1.9 to 1.13.
1.7.2 RPM Command Function
Commanding input signal either from remote control system, local control panel, and control room back-up panel (optionally).
The operator may reduce the maximum allowed speed by programming the command Limiting Function.
System control inputs automatically select "failure-mode" commanding reference, such as slow-down or back-up RPM.
Rate Limiting Function enables the operator to restrict engine acceleration or retardation.
Critical Speed Discrimination results in switch transfer of speed reference signal through the barred range.
Start - Stop Function automatically selects fuel-setting reference, with automatic transfer to speed setting reference.
Figure 1.9 RPM Command Function.
1.7.3 RPM Measurement Function
Pick-up pulses are converted to actual data value. The only scaling factor is the number of teeths on the gearwheel (pulses generated for one revolution of the engine).
Channels A and B are tested for validity, with automatic selection of correct channel.
Automatic filtering of low-speed torsional vibratory noise measurement.
High frequency filtering of speed measurement.
Additional filtering and measured data to adapt to numeric display.
Figure 1.10 RPM Measuring Function.
1.7.4
Regulator Gain Function
Error Band signal gain reduction to suppress low amplitude noise. Deadband selectable.
Governor common-gain adjusting function, to select proper damping.
Automatic adjustment of system integrating gain according to engine operating data.
Automatic adjustment of common gain according to engine operating speed.
Figure 1.11 Regulating Gain Function.
1.7.5 Fuel Limiting Function
Limiting of fuel setting according to engine propeller load characteristic.
Limiting of fuel setting according to charge air pressure curve.
Low pitch fuel limiting, mainly to limit index when restart from Bridge control (CPP-systems).
Manual limiting to fix the absolute maximum allowed fuel setting.
Selecting function, always to transmit the lowest of limited values.
Non linear compensation due to actuator position.
Non linear compensation due to fuel pump leaking when low engine speed
Scaling function, to match the actuator input signal and fuel pump offset values.
Figure 1.12 Fuel Limiting, Non Linear Compensation and Output Scaling Function
1.8.1 Fuel Actuating Function
The signal processing in DGU acts to enable the actuator to follow-up command signals as fast as possible. Electrical on/off signals are connected to the electric actuator. Position feedback signal from actuator indicates the actual position of servo.
1.8.2 Servo Control function
The main sub functions are:
Adjustable Servo PI controller.
Output Scaling for signal adaption to the Motor Servo Amplifier.
Monitoring control signals, and in case of failure, block the actuator.
Distribute fuel-indication to user (options).
Figure 1.13 Servo Control Function
2.1.1 Panel Layout
The functional layout of DGU panel is shown in Fig. 2.1. The grouping of functions are the same for the Regulator Part (left) and Actuator part (right). The following paragraphs include more detailed description.
Note that the panel has a removable change lock key. The key has to be in the OPEN position to be able to change the most critical system parameters. In addition, a special "service code" must be set to ensure that only authorized personnel are able to modify the system parameters.
2.1.2 Regulator Indicator Lamps
2.1.3 Regulator Mode Lamps
Indicate the main constraints under which the regulator function is operating.
NORMAL Normal regulating mode with real process input and output data from engine. Selection of this mode is done automatically when Cmd Handle is moved out of stop. Simulations of RPM command and Scavenge air pressure is possible when Change Lock is in Open position, also if engine is running. Simulation of Measured RPM is not possible in this mode.
IDLE Idle mode is automatically selected when RPM command handle is in stop position. All data is still monitored. The mode is now possible to change to Test, Calibrate and Self test. This is done by selecting parameter 1 (Mode select) and adjusting the data value to different values. (Alarm indication "System in Test" will lit and alarm is given to the alarm-central).
SETPOINT Direct Fuel Control mode, regardless of Measured RPM. This mode is selected when the push-button "Fuel Setpoint" is pushed and the Change Lock is in Open position. Use caution if this is done while the engine is running. This mode is a bypass function of the regulator and is normally only used to test the actuator performance.
TEST Test mode is only selectable if command handle is in stop. System may be set-up with all input data simulated, instead of real sensors.
CALIBRATE System may be set-up with special calibration signals or routines. Calibrate will also lit up if the "CAL" button is activated.
SELF TEST Self testing of computer memory is activated by pushing LAMP TEST. This will respond with "rEG-UP" if memory is ok or with "Error" if there are any memory problems. Ref. Trouble Shooting, chapter 3.
2.1.4 Regulator STATUS lamps
Indicate a running condition that restricts or reflects system performance.
REGULATOR ON System in running status. Regulation of fuel index on engine.
START Starting phase is activated. Fixed fuel in start position.
STOP System in "Engine-Stop" condition. Rpm Cmd setpoint is Zero.
RPM LIMIT ON RPM Command setting is restricted by a limiting condition, such as manual limit setting, or a critical speed range (flashing).
FUEL LIMIT ON Regulating fuel output is restricted by automatic limiting causes, such as manual limit setting, speed limiting, or scavenge air limiting. Engine is not allowed to have more fuel.
OTHER "Other" will indirectly reflect a status that can be pin-pointed by selecting appropriate parameter number for display (Parameter 9).
2.1.5 Regulator ALARM/WARNING lamps
Indicate the causes of any automatic locking of the system operation. Give
warnings about malfunctions.
LOW VOLTAGE Indicates too low voltage in one of 4 power systems: +5V, +15V, -15V, +24V. Detailed information is given by LED indicator on adaptor Card. Ref. trouble shooting, chapter 3.
RPM DETECT FAIL RPM detector (pick-up system) hardware failure. Detailed information is given by LED indicator on adaptor cards and on parameter 16. Ref. trouble shooting table, chapter 3.
IN-DATA ERROR Analog input signal failure on RPM Cmd Handle in Control-room, RPM Cmd Handle on Bridge or scavenge air sensor on engine Ref. trouble shooting.
OUT-DATA ERROR Communication failure between regulator card and actuator card. Ref. trouble shooting.
SYSTEM IN TEST Indicates that system is in test or calibration mode.
OTHER "Other" will indirectly reflect 'old Alarms' that has disappeared but is not reset by parameter 16 or 17.These two parameters will indicate which alarms that was activated. Parameter 10 will indicate "old-AL" if selected. Other Alarm will not give alarm to alarm-central since the failure is no longer there.
2.2.1 Parameter Up/Down
In the parameter area, a set of relevant parameters together with their identification numbers, are listed. After selecting a number by using the up/down buttons in the parameter area, a value will appear on the data display. Fig. 2.3
Figure 2.3 Regulator Parameter and Data Areas.
2.2.2 Data value Up/Down
Some data is Readable (like: RPM Command, Measured RPM, Charge air Pressure,,,) and some data is Adjustable (like: RPM limiter level,Fuel limiter level, Deadband,,,). The data value can be adjusted if the selected parameter is adjustable, this is achieved by pressing the "UP" or "DOWN" button in the data value section. The adjusted value will take effect immediately.
Adjustments is protected by the "Change Lock" and the "Service code", except parameter 6,7,8,14,16 and 17 (ref. parameter list).
2.2.3 Change Lock
Some parameters and some push-button may be changed/pushed only when the Commissioning Key is installed and turned to the "open" position.
2.2.4 Service code
Most critical parameters have additional safety locking by a "service code" that must be set. This service code is a special parameter that has to be set to a special value. A complete set of parameters is provided in the commissioning lists.
2.2.5 Save
Before powering off the 24 Volt, adjusted data can be saved by pressing the "SAVE" button, when the Change Lock is in Open position. If save is not pressed after an adjustment, the "old adjustments" will appear next time the power-supply has been off and then on again.
2.3 Regulator Operating Buttons
How to change regulating function in running conditions. Each button has its own on/off LED indicator. The indicator signal is feed back to the panel from the computer, in response to button operation. The buttons are showed in Fig. 2.4.
Note that DEAD BAND and ROUGH SEA buttons may be selected with no restriction. The FUEL SETPOINT button may be operated only when the key-lock is unlocked and the function parameter is enabled.
2.3.1 Constant Fuel Mode Button
On: If LED on push button is lit then deadband is real (flat). The Constant Fuel Mode function reduces the motions of the governor. When engine speed is within the deadband limits, there is no movement of fuel rack. This function will cause more variations and also a possible constant deviation on the engine speed. Deadband value is adjustable on parameter no. 8 and is usually set to 2 RPM for normal running at sea. This value can be increased for more stabile actuator. However, special plant consideration may limit practical use of this function if there is an shaft generator or similar equipment.
Off: If LED is not activated, the regulator will work with a reduced gain in the deadband zone. The reduction is adjustable and called "Reduction Gain". Reduction-factor of 5 means that the activity of actuator is reduced with 5 times. A deadband value of 2 means ± 2 RPM.
2.3.2 Rough Sea Button
On: If led on the Rough Sea button is activated, the regulator selects the Rough Sea gain-setting for PI governor. Ref. parameter list. In addition the regulator can connect a Derivative function making the governor a PID regulator. The D-function is selected on parameter 73 "D-gain On/Off". These alternate values may be programmed to adapt more to a special sea-going condition, such as ballasted vessel, or rough sea situations.
Off: If led on the Rough Sea button is not activated, the regulator selects the "normal" PI governor settings.
2.3.3 Fuel Setpoint Button
This function is under the Change Lock, so the Key is necessary to activate this function!
On: Transfer the system mode unconditionally to NORMAL and SETPOINT. In setpoint mode, the fuel index is directly set by the Commanding RPM Handle. Setting the RPM Cmd Handle to "Dead Slow" will give 0% fuel and "Full" will give 100% fuel, independent of the engine speed. The scaling of this function can be done at fuel setpoint parameters. The fuel limiters will still work so engine will not be overloaded with fuel, but it may easily be over-speeded. (See also fuel setpoint mode).
Off: Regulator in normal regulating mode.
Figure 2.4 Regulator Operation Buttons.
2.3.4 Regulator Test Buttons
The test buttons may be used in all system modes. Pressing one of the upper buttons makes it possible to input a data value directly from the panel. The simulated input will initially equal that of the transducer, then be increased or decreased by the (+) or (-) button, respectively.
To direct the adjustment to only one of the signals given, the relevant button has to be pressed for a short time. When the button lamp starts flashing, the adjustment of the selected data is possible. A long press of the button resets the data to the original source.
The adjustments are visual by selecting the appropriate parameter number. The RATE-button allows the adjustment to be slow or fast.
The parameters to be simulated are:
CMD | RPM Command input | Parameter 2 |
RPM | RPM Measured | Parameter 3 (not in NORMAL mode) |
CHARGE AIR | Charge Air Pressure | Parameter 5 |
Figure 2.5 Regulator Test Buttons.
Note that the CAL. button may be used in normal running mode to add an artificial square-wave noise in the RPM measurement. This is to be able to observe the regulating action of the governor.
2.4.1 Actuator Indicator Lamps
Figure 2.6 Actuator Indication lamps.
Any number of lamps may be lit at the same time. Operation of the lamps is as follows:
2.4.2 Actuator MODE lamps
NORMAL System in normal, regulating, mode with real process input and output data.
IDLE System in a "ready-to-go" mode, doing all monitoring and transferring of all input data.
TEST System test and simulation mode, that allows input data to be simulated from operator panel instead of real sensor inputs.
CALIBRATE Not used in this version.
SELFTEST Self test of the microcomputer memory is activated by addressing button RESET / LAMP TEST.
2.4.3 Actuator STATUS lamps
SERVO ON Servo operation is active.
MANUAL CONTR. Actuator may be manually positioned by operating (+) and (-) test buttons.
EXTERNAL STOP The servo command input is forced to STOP by external emergency-stop activation or Shut Down/Overspeed.
SERVO BLOCKED The actuator is blocked, caused by a fatal system error condition.
OTHER Other system status is flagged. Selection of appropriate parameter number gives additional information.
2.4.4 Actuator ALARM lamps
LOW VOLTAGE Indicates too low voltage in one or more of the 4 power systems: +5V, +15V, -15V, +24V. Details are shown on LED indicators on adaptor card.
FEEDBACK FAIL Feedback error caused by signal failure in actuator position measuring.
IN-DATA ERROR Cluster of errors that may be detected by the input data self-test routines. Error decoding is shown if selecting the appropriate parameter number.
SERVO AMPL FAIL. Failure in the servo amplifier system (DSU, SBS, ABS or actuator).
SYSTEM IN TEST System in test or calibration mode.
OTHER Other system alarm or warning is indicated. Selection of appropriate parameter number gives additional information.
2.4.5 Actuator Parameter and Data Areas
In the parameter area a set of relevant parameters, together with their identification numbers, are listed.
After selecting a number by using the up/down buttons in the parameter area, a value will appear on the data display. Fig. 2.7 shows an example of having selected the measured fuel output of the system, which displays a value of 50.0 pump index.
Figure 2.7 Actuator Parameter and Data Areas.
The fuel output is measured input signal to the system. In such a case, no new value would appear in the data display if the operator tried the up/down buttons in the data area. For this to happen, the selected parameter must be of an adjustable type, such as no. 5.
The change key has to be in "unlocked" position to be able to change any parameter value. Most critical parameters have an additional safety-lock, by means of a "service code" to be set, having first selected the proper parameter number. A complete list of parameters is provided in the commissioning lists.
