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Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
Chapter 5
CGCM-DLR Unit Startup
Verify Operation of Limiter Functions and Diode Monitor
Perform the following tests to verify Limiter Functions and Diode Monitor
operation.
Volts/Hz Operation
Perform this test with the generator operating unloaded in Constant Speed mode
and constant voltage AVR mode.
Follow these steps to test the Volts/Hz operation.
1.
With the generator circuit breaker open, adjust the prime mover speed
down to just above the configured V/Hz upper knee frequency.
Verify that the voltage remains constant.
2.
Adjust the prime mover speed down to below the configured V/Hz upper
knee frequency.
Verify that the voltage decreases at the configured upper slope rate.
3.
Adjust the prime mover speed down to below the configured V/Hz lower
knee frequency.
Verify that the voltage decreases at the configured lower slope rate.
Under-excitation Limiting (UEL) Operation
Perform this test with the generator operating in parallel (droop or PF/VAR
control) with a large power source that is maintaining constant voltage.
Follow these steps to test the UEL operation.
1.
Disable the UEL function.
2.
Set the online under-excitation limit for 5% VARs into the generator.
3.
To create an under-excited condition, adjust the VARs into the generator
for 15% at 25% load.
4.
To create a step change into the UEL limit, enable the UEL function.
5.
Observe the response of the excitation current reported by the
CGCM-DLR unit.
6.
Adjust the UEL gains as required to obtain the desired stable response.
7.
Verify stable performance of the UEL by testing the machine from
25…100% real power loading while under excited.
8.
Increase the excitation above the UEL limit.
9.
Return the UEL settings to the values determined for the application.