For a governor turbine with speed droop, when there's a step load change, the speed will not return to the nominal value towards steady state. This is due to the inherent droop characteristic, and thus the speed error will not converge to zero.

There's possibility to bring the speed back to nominal value by introducing the load reference setpoint, am I right? I'm quite confused with this load reference setpoint, how do I adjust the speed and load by changing the load reference setpoint? Could anybody clarify this?

Many thanks.

 

1. Only in the isolated operation (not connected to a large grid), a step load change will cause change in speed of the turbine. At steady state speed will be different from the previos value.

2. To restore speed to thr normal value, speed reference is to be adjusted either automatically or manually.

3. In the older versions of governors, speed/load reference used to be the same.Till the machine is synchronized the set point is used to cahnge the speed. After synch. to a large grid the speed does not change but only power poutput changes.

4.In the later versions speed set point and load (or gate) set point are separately provided. Load set point may track the actal load in isolated operation.

5 Different alternatives are possible. When there is circuit breaker opening, a signal may change the the speed reference automatically, to restore speed the normal value.