Synchronous machine voltage problem, thanks

Discussion in 'Homework Help' started by epicfrank, Nov 15, 2015.

  1. epicfrank

    Thread Starter New Member

    May 26, 2013

    I am a student doing a electrical machine course and i was given a question which says

    "A 200kVA, 660V, 50Hz, 4-pole star-connected synchronous generator has a synchronous reactance of 1 ohm per phase. When the machine is operating at lagging power factor, rated voltage and current, the torque angle δ=tan-1(0.2). Calculate the power factor and torque

    The 660V means the line voltage right? In the answer there is this diagram:

    屏幕快照 2015-11-15 下午10.34.12.png

    I am not sure should the phase voltage be calculated by 660/root3=381.1V because the phase voltage is the voltage of the load end and there is a armature reactance on the way, shouldn't the 381.1v be the generator internal EMF in the triangle?

    Many thanks in advance!