Question

A non-salient pole synchronous generator having synchronous reactance of 0.8 pu is supplying 1 pu power to a unity power factor load at a terminal voltage of 1.1 pu. Neglecting the armature resistance, the angle of the voltage behind the synchronous reactance with respect to the angle of the terminal voltage in degrees is _______

Answer 1

Concept:

For a synchronous generator,

E = V + I_aZ_s

Explanation:

Given that,

X_s = 0.8 pu, P = 1.0 pu, upf

V = 1.1 pu, Ra = 0

Power of a non-salient pole synchronous generator can be defined as P = VI_a cos ϕ

1 = 1.11 × I_a × 1

I_a = 0.91 pu

E = V + I_aZ_s

= 1.11∠0 + 0.91 ∠0 × 0.8 ∠90°

= 1.319 ∠33.49

The required angle = 33.49°