A 480V, 50HZ, Y-connected, six-pole synchronous generator has a per-phase reactance of 1.0 2. Its full load armature current is 60A at 0.8PF lagging. The generator has friction and windage losses of 1.5kW and core losses 1.0kW at 60HZ at full load. Since the armature resistance is ignored, assume that the copper losses are negligible. The field current is adjusted such that the terminal voltage is 480V at no load. Draw the phasor diagram of the armature. (a) What is the speed of rotation of this generator? (b) What is the terminal voltage of this generator if it is loaded with the rated current 0.8PF leading? (c) What is the efficiency of the generator at rated current and 0.8 PF leading? (d) How much shaft torque must be applied by the prime mover at full load? How large the induced counter torque?

A 480V, 50HZ, Y-connected, six-pole synchronous generator has a per-phase reactance of 1.0 2. Its full load armature current is 60A at 0.8PF lagging. The generator has friction and windage losses of 1.5kW and core losses 1.0kW at 60HZ at full load. Since the armature resistance is ignored, assume that the copper losses are negligible. The field current is adjusted such that the terminal voltage is 480V at no load. Draw the phasor diagram of the armature. (a) What is the speed of rotation of this generator? (b) What is the terminal voltage of this generator if it is loaded with the rated current 0.8PF leading? (c) What is the efficiency of the generator at rated current and 0.8 PF leading? (d) How much shaft torque must be applied by the prime mover at full load? How large the induced counter torque?