Question

In a salient pole synchronous generator connected to an infinite bus bar, maximum power is delivered at a power angle:
1. δ < 90°
2. δ = 45°
3. 45° < δ < 0°
4. δ = 0°

Answer 1

Correct Answer - Option 1 : δ < 90°

Explanation:

Maximum excitation power occurs at 90° and maximum power due to reluctance occurs at 45°. Therefore, the maximum power developed in salient pole synchronous machine occurs at a load angle less than 90°.

An alternator's power output is directly proportional to the sine of its load angle.

\(P = \frac{{EV}}{X}\sin\theta\)

Where,

P = Power output of the alternator

E = Sending voltage of the alternator

V = Receiving voltage of the alternator

X = Rectance of alternator

θ = Load angle

The maximum power output from the alternator would occur when the load angle is < 90 degrees.