Question

Calculate the displacement factor if the fundamental voltage is 24sin(140πt-240°) and fundamental current is 47sin(140πt-120°).

(a) -0.5

(b) -0.7

(c) 0.9

(d) 0.4

This question was posed to me in unit test.

Query is from Solid State Controlled Drives topic in section Introduction to Solid State Controlled Drives of Electric Drives

Answer 1

Correct option is (a) -0.5

The explanation is: The displacement factor is the cosine of the angle difference between the fundamental voltage and fundamental current. D.F=cos(120°)=-0.5.