Torque Analysis of the Hysteresis Motor with Over-excitation Using Play Model

The short-duration over-excitation of the hysteresis motor running at synchronous speed reduces the stator current and increases the pull-out torque at the same time. This paper presents new hysteresis torque analysis using B-H loop in the rotor hysteresis ring of the hysteresis motor with over-excitation at an arbitrary load, where the time-stepping finite element method (FEM) using play model is used. The behavior of the operating point on B-H loops before and after the over-excitation is clear from simulation results using the play model. The calculated value of the hysteresis torque obtained from the B-H loop area versus space agreed well with the measured one.