##### Reference no: EM13226720

A 75-kVA, 230-V/115-V, 60-Hz was tested with these results: Open-circuit test: 115 V, 16.3 A, 750 W; Short-circuit test: 9.5 V, 326 A, 1200 W

a) Determine the voltage regulation at rated load, 0.8 power factor lagging.

b) Efficiency at rated load, 0.8 power factor lagging and a half load, unity power factor.

For part a, I know 9.5/230= 0.0413 pu= v

p1= 1200/75k= 0.016

x= square root of 0.0413^2 - 0.016 ^2= 0.0384 pu

How do we get voltage regulation?

For part b, I have no problem with efficiency rated load which is 96.85 but how do we find the half load efficiency?