Alarm deviation examples
1. The controller is trying to control the genset to run at 50 Hz, and the measured frequency is 49.5 Hz.
•
The deviation from the set point is |(49.5 Hz - 50 Hz)| / 50 Hz =0.01 = 1 %.
•
The deviation is less than the alarm set point, and the alarm is not activated.
2. The controller is trying to control the genset to run at 60 Hz and the measured speed is 62 Hz.
•
The deviation from the set point is |(62 Hz - 60 Hz)| / 60 Hz = 0.03 = 3.3 %.
•
The deviation is less than the alarm set point, and the alarm is not activated.
3. The controller is controlling 1500 kW genset, and is running fixed power regulation with a set point of 1000 kW. The
measured power is 600 kW.
•
The deviation from the set point is |(600 kW - 1000 kW)| / 1000 kW = 0.4 = 40 %
•
The deviation is more than the alarm set point. If the measured power is stays below 700 kW for longer than the
delay, then the alarm activates.
6.8.2 AVR regulation error
This alarm shows when there is an error with the AVR controlled regulation.
The alarm is based on the difference between the measured value and the required set point, as a percentage of the set point. The
larger the set point, the more the measured value is allowed to differ from the set point.
The alarm activates if the measured value is outside of the permitted range for longer than the delay.
INFO
This alarm is not activated when the genset voltage swings in and out of the permitted range above and below the set
point. This is because this alarm only activates when the measured value is constantly above the upper limit, or constantly
below the lower limit for the entire delay period.
Configure the parameters under
Configure > Parameters > Regulators > AVR monitoring > Regulation error
.
INFO
Do not set the alarm set point lower than the deadband percentage for relay regulation. Doing so might activate the alarm
in an area where regulation is not possible.
Table 6.12
Default parameters
Parameter
Range
Default
Set point (absolute value)
1 to 100 % regulation deviation
30 %
Delay
10 s to 1 h
60 s
Enable
Not enabled, Enabled
Enabled
Alarm action
Warning
Alarm deviation examples
1. The controller is running fixed voltage regulation with a set point of 400 V, and the measured voltage is 250 V.
•
The deviation from the set point is |(250 V - 400 V)| / 400 V × 100 = 38 %.
•
The deviation is more than the alarm set point. If the measured power is stays below 280 V for longer than the
delay, then the alarm activates.
2. The controller is running fixed reactive power regulation with a set point of 0 % of nominal reactive power, and the
measured value is 2 % of nominal reactive power.
•
The deviation from the set point is 2 %.
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