Question

What is the relation between ‘ω’, angular speed in electrical radians per second and ‘ωm‘, angular speed in mechanical radians per second, for a P-pole machine?

(a) ω = 2/Pωm

(b) ω = 4/Pωm

(c) ωm = P/2ω

(d) ω = P/2ωm

I had been asked this question during an internship interview.

I want to ask this question from Terms Pertaining To Rotating Machines topic in division Basic Concepts in Rotating Machines of Electrical Machines

Answer 1

Right choice is (d) ω = P/2ωm

To explain I would say: We know θelec = P/2θmech ⇒ d/dt(θelec) = P/2d/dt(θmech) ⇒ ω = P/2ωm.