(b) A 50 MVA, 30 kV, three-phase, 50 Hz synchronous generator have a synchronous reactance of 9 12 per phase and a negli
Posted: Mon May 02, 2022 2:45 pm
(b) A 50 MVA, 30 kV, three-phase, 50 Hz synchronous generator have a synchronous reactance of 9 12 per phase and a negligible resistance. The generator is delivering rated power at 0.8 power factor lagging at the rated terminal voltage to an infinite bus. (i) Determine the excitation voltage, E in each phase and the power angle, 8. (5 marks) (ii) Determine the armature current and the power factor when the driving torque is reduced until the generator is delivering 30 MW with the excitation voltage held constant at the value found in Q1(b)(i). (4 marks) If the generator is operating at excitation voltage as part Q1(b)(ii), determine the maximum power occur at power angle, 8 equal to 90°. (1 mark) (iv) Find the armature current and the power factor corresponding to maximum power in Q1(b)(iii). (2 marks)