A unified approach to the analysis of single-phase induction motors

Single-phase motors are manufactured with a wide variety of capacitor/winding arrangements and interconnections. The bewildering array of motor variants is commonly analyzed using a two-axes model for each and every winding configuration. MMF harmonics are often ignored to limit the complexity. This paper describes a unified model based upon the more familiar rotating-field approach that includes MMF harmonics. Winding interconnections are modeled using simple connection matrices that do not interfere with the core motor model. The method is powerful and flexible and can be interfaced easily to a variety of techniques for determining the equivalent-circuit parameters, such as finite elements, for example. The paper illustrates the unified approach using a two-speed single-phase capacitor motor.