Answer Happy

= Q1. A generator has synchronous reactance Xd = 2 pu and is connected to a very large system. The terminal voltage is 120° per unit and the generator is supplying to the system a current of 0.8 per unit at 0.85 power factor lagging. All per unit values are on machine base. (a) Neglecting resistance, find the magnitude and angle of the machine internal voltage. Plot the phasor diagram that illustrates the solution. Calculate the active and reactive power delivered by the generator (5 marks) (b) Increase the excitation in (a) by 25%, find the angle between machine terminal and internal voltage. Calculate the reactive power delivered by the generator (2.5 marks) (c) Decrease the excitation in (a) by 25%, find the angle between machine terminal and internal voltage. Calculate the reactive power delivered by the generator. (2.5 marks)