7/28/2019 CDVR Troubleshooting
1/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
CDVR Troubleshooting
October 30, 2007
7/28/2019 CDVR Troubleshooting
2/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Outline
Troubleshooting
If operation is not as expected
Excitation loss (reverse kvar)
Generator over voltage
Generator under voltage
No generator voltage
Exciter diode monitor fault
7/28/2019 CDVR Troubleshooting
3/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Outline (continued)
Troubleshooting
Over excitation fault
Loss of sensing
Field over current
Internal Memory Failure
Internal Watchdog Failure
Unstable Voltage
Poor Transient Response
7/28/2019 CDVR Troubleshooting
4/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
CAUTION
7/28/2019 CDVR Troubleshooting
5/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If Operations is not as Expected:
Check for Alarms or Shutdown Faults
If Fault LED is lit Continuously Alarm Output Drive Active
If Fault LED is Flashing Shutdown Output Drive Active
Open Communications with CDVR to determine what Alarm /Shutdown is active
Alarm Signal Indicator Visible on all Screens
Go to Metering Screen, look at Alarms area
Check Programmable Settings
7/28/2019 CDVR Troubleshooting
6/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
CAT PC Metering Screen
7/28/2019 CDVR Troubleshooting
7/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
CAT PC Protection Screen
7/28/2019 CDVR Troubleshooting
8/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If Excitation Loss(Reverse kvar) has Occurred:
Verify programmable settings are consistent with application
Check wiring of generator voltage (P12 10 to 12) and Current
Sensing (P12 1 & 2) Check phase rotation, if not consistent with wiring diagram,
modify connections
Check other paralleled generators or voltage sources for over
voltage (this can cause reverse var flow into generator) Replace regulator
7/28/2019 CDVR Troubleshooting
9/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If Generator Over Voltage has Occurred:
Check wiring of generator voltage sensing (P12 10 to 12)
Verify that the generator over voltage fault settings are correct
Verify that voltage adjustment is not set too high
Verify that sensing PT (if used) has correct turns ratio
Verify that sensing PT fuses (if used) have not opened
High voltage may occur if operating in droop mode withcapacitive load or if CT connection is backwards or wrong phaserotation
High voltage may occur if operating in line drop compensationmode with a large generator load
Verify auxiliary input voltage is not too high
Replace regulator
7/28/2019 CDVR Troubleshooting
10/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If Generator Under Voltage has Occurred:
Check wiring of generator voltage sensing (P12 10 to 12)
Verify that the generator under voltage fault settings are correct
Verify that voltage adjustment is not set too low
Verify that the generator is running at rated speed
Verify that the under frequency setpoint (knee frequency) is notgreater than generator frequency
Verify that sensing PT (if used) has correct turns ratio
Check for correct input power
Low voltage may occur if operating in droop mode with highinductive load
Verify auxiliary input voltage is not too low
Replace regulator
7/28/2019 CDVR Troubleshooting
11/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present:
Check wiring
Verify that the generator is running at rated speed
Verify that residual voltage applied to the power input is at least6Vac or greater
Verify that the fuse is not open
Verify that CDVR is connected to 24Vdc control power
Verify that common alarm / shutdown LED is not flashing
7/28/2019 CDVR Troubleshooting
12/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and an Exciter Diode MonitorFault has Occurred:
Stop machine
Insure power input to CDVR has been removed, unplug P6 Refer to generator manual for instructions on checking the
rotating exciter diodes
If no fault is found with rotating exciter diodes, the EDM trip value
may be too low Increase EDM trip value to a level greater than the ripple current
under normal operation
If rotating exciter diodes are at fault, repair, reinstall P6 then
reset the CDVR using the Fault Reset contact input or cycle the24Vdc control power
7/28/2019 CDVR Troubleshooting
13/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and an Over Excitation Fault hasOccurred:
Stop machine
Check generator and load conditions for a fault that could causeexcessive exciter field current
If no fault is found, reset the CDVR using the Fault Reset contact input
or cycle the 24Vdc control power
Verify the over excitation settings are properly adjusted for the
generator, set slightly above the requirement of the application but notso high as to render the protection ineffective
If an exciter diode fault has occurred, the instantaneous trip value of
28A may have been reached. The EDM fault will not indicate this, due toa 5 sec time delay
SR4 &SR4B generator require up to 12Adc for full load. A 10 second
setting is required to insure 300% short circuit requirements
7/28/2019 CDVR Troubleshooting
14/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and a Loss of Sensing Fault hasOccurred:
Stop machine
Check wiring Check generator and load conditions for a fault that could cause
sensed voltage to be low
If sensing potential transformers are used, verify that they are
functional and have not blown a fuse Once fault is repaired, reset the CDVR using the Fault Reset
contact input or cycle the 24Vdc control power
7/28/2019 CDVR Troubleshooting
15/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and a Field Over Current Faulthas Occurred:
Stop machine
Check wiring Check generator and load conditions for a fault that could cause
a field over current
A field over current fault occurs when output current exceeds
28A (approximately) Once fault is repaired, reset the CDVR using the Fault Reset
contact input or cycle the 24Vdc control power
7/28/2019 CDVR Troubleshooting
16/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and an Internal Memory FailureFault has Occurred:
Try resetting the CDVR using the Fault Reset contact input or
cycle the 24Vdc control power If after resetting the CDVR, if another Internal Memory Failure
fault occurs, replace regulator
7/28/2019 CDVR Troubleshooting
17/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
If No Generator Voltage is Present and an Internal Watchdog FailureFault has Occurred:
Try resetting the CDVR using the Fault Reset contact input or
cycle the 24Vdc control power If after resetting the CDVR, if another Internal Watchdog Failure
fault occurs, replace regulator
7/28/2019 CDVR Troubleshooting
18/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
Unstable Voltage:
Verify that the governor for the engine is operating properly
Verify that the sensing and power leads are connected securely
Verify that the CDVR stability range is set to the proper range Verify that the stability level (Kg) is properly set
7/28/2019 CDVR Troubleshooting
19/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
Poor Voltage Response to a Transient Load:
Verify that the governor for the engine is operating properly
Verify that the CDVR stability range is set to the proper range
Verify that the stability level is properly set Tune the CDVR for the application
7/28/2019 CDVR Troubleshooting
20/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
CDVR PID Tuning:
Perform a step of reference test with 1 or 2% steps
Look at terminal voltage response with chart recorder
Determine if voltage response is acceptable Rise time
Over shoot
Settling time
Damping
If not acceptable, tune the CDVR for the application
Once step of reference test is suitable, verify load application /rejection performance
7/28/2019 CDVR Troubleshooting
21/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Step of Reference Test
Rise Time
7/28/2019 CDVR Troubleshooting
22/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Step of Reference Test
Over Shoot
7/28/2019 CDVR Troubleshooting
23/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Step of Reference Test
Settling Time
+/- 2%
7/28/2019 CDVR Troubleshooting
24/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Step of Reference Test
Damping
7/28/2019 CDVR Troubleshooting
25/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Troubleshooting
CDVR PID Tuning:
Examples of step of reference test results
Tests performed on 300kW, 240V, 60Hz AREP generator
Factory defaults PID calculator
Magic PID values = 80, 20 and 10
7/28/2019 CDVR Troubleshooting
26/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Default PID = 200, 600, 30 with Kg = 50
7/28/2019 CDVR Troubleshooting
27/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Default PID = 200, 600, 30 with Kg = 25
7/28/2019 CDVR Troubleshooting
28/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Default PID = 200, 600, 30 with Kg = 10
7/28/2019 CDVR Troubleshooting
29/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Default PID = 200, 600, 30 with Kg = 1
7/28/2019 CDVR Troubleshooting
30/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
PID Calculator, Tdo = 2s, Te = 0.1s
PID &Kg = 25, 43, 2.7 & 50
7/28/2019 CDVR Troubleshooting
31/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
PID Calculator, Tdo = 2s, Te = 0.1s
PID &Kg = 25, 43, 2.7 & 200
7/28/2019 CDVR Troubleshooting
32/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
PID Calculator, Tdo = 1.5s, Te = 0.1s
PID &Kg = 25, 51, 2.6 & 200
7/28/2019 CDVR Troubleshooting
33/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
PID Calculator, Tdo = 1.0s, Te = 0.1s
PID &Kg = 42, 100, 4.5 & 200
7/28/2019 CDVR Troubleshooting
34/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Magic PID Values = 80, 20, 10
Kg = 50
7/28/2019 CDVR Troubleshooting
35/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
PID Tuning Conclusion
Must adjust Kg to achieve best results
Factory Default Values result in OK performance
PID Calculator gives very good results but must know Tdo and Te
Magic PID values also very good and it is simple Once step of reference test is suitable, verify load application /
rejection performance
7/28/2019 CDVR Troubleshooting
36/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
Information Needed If Replacement of CDVR is Selected
When sending back a CDVR, please provide the following:
Detailed statement of problem including
Symptoms of the failed CDVR
Genset configuration and ratings Operating Conditions (kW, voltage, current etc)
Run time
Anything unique about the installation
Did anything of significance occur just before the failureoccurred? (i.e. sparks, re-wiring, etc.)
Is there any mechanical damage to the CDVR or mounting?
7/28/2019 CDVR Troubleshooting
37/37
EAME/CIS TC Conference EP/Petroleum - Malaga, October 2007
QUESTIONS?
Top Related