Single-phase induction motor with permanent magnet excitation

A permanent magnet excited single-phase induction motor (SIM) has a very simple mechanical structure. Its stator is similar to that of shaded-pole or single-phase synchronous motors. However, there are two rotors: a diametrically magnetized permanent magnet cylinder rotating freely that is mounted within a copper cup linked to the load. Field equations describing its stationary behavior are solved analytically for a simplified motor geometry. From these performance characteristics are calculated and compared with measurements. Guidelines for design optimizations are derived.