Effect of MMF Harmonics on Single-Phase Induction Motor Performance - A Unified Approach

Single-phase and two-phase induction machines are widely used in commercial applications due to their low cost and high reliability. The developed methods for the analysis of the single-phase induction motor, i.e. forward-backward field, symmetrical components and cross-field methods, can be adapted for modeling the MMF harmonics effect. This paper presents a unified approach on all these methods that demonstrates the equivalence between models and shows how the equivalent circuit elements can be interchanged from one method to another. Since half-cycle symmetry is a very common condition in the mass produced single-phase induction motors, this paper analyses only the odd MMF harmonic effects. Experimental results for three capacitor-run motors are used to validate all the proposed models.