Question

(360) Volt, 60 Hz, 600 hp, 0.6 pf-leading, four-pole -connected synchronous motor has 0.9Ω synchronous reactance. Friction; wind; core losses and armature resistance are neglected.

a) If the motor is operating under magnitude of phase current (ia) (180)

Ampere and power factor of 0.6 lagging,

1. Find the input power of motor in hp

2. Find the generated voltage, EA

3. Find the torque and the maximum inducible torque in current state.

b) If EA is increased by 18% find,

1. Magnitude of new armature current (ia),

2. New power factor of motor.

Answer 1