Generator
Actual load
Voltage on load sharing line
Generator 1
100 %
4 V DC
Generator 2
0 %
0 V DC
The voltage level on the load sharing line can be calculated to:
ULS: (4 + 0)/2 = 2 V DC
Now generator 1 will decrease the load in order to match the voltage on the load sharing line (in this example
2 V DC). Generator 2 will increase the load in order to match the 2 V DC.
The new load share situation will be:
Generator
Actual load
Voltage on load sharing line
Generator 1
50 %
2 V DC
Generator 2
50 %
2 V DC
Example 2:
In case of generators of different sizes, the load sharing will still be carried out on the basis of a percentage of
the nominal power.
Two generators supply the busbar. The total load is 550 kW.
Generator
Nominal power
Actual load
Voltage on load sharing line
Generator 1
1000 kW
500 kW
2 V DC
Generator 2
100 kW
50 kW
2 V DC
Both generators are supplying 50 % of their nominal power.
Ramp up function
In the menu 2610, it is possible to enable a power ramp up function when operating in load sharing mode.
When this function is enabled, the GPC-3 will not balance the load immediately when the breaker is closed,
but will follow the adjusted power ramp up curve (menu 2141). This means that the other generator(s) will
carry the majority of the load during the time where the actual generator is in its ramp up sequence.
The power set point is still reflecting the reference on the load sharing line (0 to 4 V DC ~ 0 to 100 %). When
the generator has reached the set point, it follows the load without further ramp functions.
The ramp function is initiated when P load sharing mode is selected and the GB closes.
If the ramp up delay point (menu 2613) is used, the actual power production during the delay
period will not match the adjusted value exactly. This is because the regulator set point is a
mix between the power and frequency controllers when operating in load sharing mode.
GPC-3 DRH 4189340587 UK
Additional functions
DEIF A/S
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