Equivalent Circuit Model for a Shaded-Pole Induction Motor: I. One Shading Coil and a Uniform AIR Gap

The rotating coupled circuit equations for a smooth air gap induction motor with two windings at an arbitrary displacement angle are transformed to formulate d-q, forward-backward, and equivalent circuit models. Shaded-pole performance is simulated by setting the auxiliary winding voltage to zero and adding the effect of mmf harmonics. Comparisons to test data show good correlation except for the value of starting torque, a result attributable to the use of an average air gap length when simulating the stepped air gap test motor.