Checking the control range example
If the nominal frequency is 50 Hz, the frequency control range for the governor is typically 48 to 52 Hz.
If one pulse from the relay outputs corresponds to a 1 Hz change, it will be impossible to control the frequency
accurately enough for synchronisation.
If 100 pulses are required from the relay outputs to change the frequency by 1 Hz, then the frequency will respond
too slowly to the relay outputs.
6.2.2 Setting up relay-controlled regulators
For governor relay outputs, set the Period time and the Minimum ON time under Configure > Parameters > Regulators >
Governor: Relay output settings > Configuration.
For AVR relay outputs, set the Period time and the Minimum ON time under Configure > Parameters > Regulators > AVR:
Relay output settings > Configuration.
INFO
Keep in mind that the relay-controlled governor/AVR can respond to the number of control pulses and/or the width
of the pulse. If the governor/AVR responds to the width of the pulse, the control response is not necessarily linear.
Number of control pulses
If the governor/AVR only responds to the number of control pulses, and the control is too slow, you can reduce the Period
time. Similarly, if the control is too fast or unstable, you can increase the Period time.
INFO
Activate switchboard control and use the switchboard buttons to regulate the governor/AVR. You can estimate the
governor/AVR response time by measuring how many control impulses are needed for stable control. Match the
Period time to the governor/AVR response time.
Width of the pulse
If the governor/AVR only responds to the width of control pulses, and the control is too slow, you can increase the Minimum
ON time. Similarly, if the control is too fast or unstable, you can reduce the Minimum ON time.
INFO
The Period time should be about 5 × Minimum ON time.
INFO
You can use a multimeter (use the continuity tester "beep" setting) to verify the output from the controller's relay-
controlled regulators.
See Regulation, Introduction, Relay regulation in the Designer's handbook for more information.
6.2.3
Tuning P regulators
The relay-controlled regulators use proportional control. You can also set a Deadband (a percentage of the nominal value).
PPU 300 Commissioning guidelines 4189341106 UK
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