Question

Calculate the compensator rating required for a sec(Φ)=1.

(a) 0.64 P.U

(b) 0.21 P.U

(c) 0.57 P.U

(d) 0 P.U

I have been asked this question in an interview for internship.

This question is from Motors Rating and Heating topic in section Rating and Heating of Motors of Electric Drives

Answer 1

The correct choice is (d) 0 P.U

For explanation: The compensator rating can be calculated using the relation QP.U=√1-cos^2(∅)=0. This per unit value VAR compensator is required to improve the power factor of the system.