The total load is 900 kW. The internal controller set point Genset A is therefore 600 kW, and the set point for Genset B is
300 kW, that is, 60 % of nominal power.
Genset A supplies 500 kW, and Genset B supplies 400 kW.
For Genset A, the load sharing error is (500 kW - 600 kW) / (1 000 kW) = -0.1 = -10 %
For Genset B, the load sharing error is (400 kW - 300 kW) / (500 kW) = 0.2 = 20 %
4.10.3 P load sharing failure (low frequency) on DG
This advanced blackout prevention alarm can be activated if there is both a low frequency and a
negative P load sharing error at a GENSET controller.
Controller types: This alarm is present in GENSET, and BUS TIE breaker controllers.
Set
point
time
Delay
Limit
GENSET controllers
Configure the parameters under
Configure > Parameters > Local power management > Advanced blackout prevention > P
load sharing failure (low frequency)
.
Table 4.29
Default parameters
Parameter
Range
Default
Low frequency limit
90 to 110 %
99 %
Set point
-100 to -0.1 %
-20 %
Delay
0 s to 1 h
3 s
Enable
Not enabled, Enabled
Not enabled
Latch
Not enabled, Enabled
Enabled
Action
Trip generator breaker
BUS TIE breaker controller
Configure the parameters under
Configure > Parameters > Local power management > Advanced blackout prevention > P
load sharing failure (low frequency)
.
Table 4.30
Default parameters
Parameter
Range
Default
Low frequency limit
90 to 110 %
99.5 %
Set point
-100 to -0.1 %
-20 %
Delay
0 s to 1 h
2 s
Enable
Not enabled, Enabled
Not enabled
Latch
Not enabled, Enabled
Enabled
Action
Trip bus tie breaker
Inhibit
Bus tie breaker open
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