QUESTION 1 [25 MARKSI A 100hp, 440V, 0.8 power factor lagging, A-connected synchronous motor has negligible armature res
Posted: Fri May 20, 2022 6:58 pm
QUESTION 1 [25 MARKSI A 100hp, 440V, 0.8 power factor lagging, A-connected synchronous motor has negligible armature resistance and a synchronous reactance of 412. This motor has an efficiency of 96% when operating at rated condition. (a) The synchronous motor is operating at rated conditions. (i) Calculate the real input power (Pin), line current (IL), phase current (IA.p), and the per-phase internal generated voltage (EAC). [4 marks) (ii) What is the reactive power of the synchronous motor operating in part (a)? Determine whether the motor is supplying the reactive power to the system or consuming the reactive power. Draw the phasor diagram of the synchronous motor operating in part (a). [6 marks) (b) The user decides to increase the flux in the machine by 50%. (i) Calculate the new internal generated voltage (EA,b), the torque angle (S), the armature current (14.6) and the power factor of this synchronous motor when the flux is increased. 19 marks) (ii) Draw the phasor diagram and provide a comparison of the motor operation in part (a) and in part (b) (i). [6 marks)