Power angle characteristic of salient pole machines
Power angle characteristic:
Fig shows the power-angle characteristic of a salient-pole machine. It is clear that reluctance power varies with δ at twice the rate of the excitation power.
The peak power is seen to be displaced towards δ = 0, the amount of displacement depends upon the excitation.
In Fig., the excitation is such that the excitation term has a peak value about 2.5 times that of the reluctance term. Under steady-state conditions, the reluctance term is positive because Xd > Xq.