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.