Computation of Hysteresis Torque and Losses in a Bearingless Synchronous Reluctance Machine

This paper presents the methodology and computation results for the torque and iron losses in a bearingless synchronous reluctance machine. The aim is to compute the hysteresis torque related to the asynchronous operation of the machine under the effect of the levitation field rotating at twice the synchronous speed. For this purpose, and because it is impossible to compute the hysteresis torque with a single-valued B-H characteristic, a magneto-dynamic vector hysteresis model is used. The computations show that the hysteresis-related shaft power is considerable under no-load operation of the machine. It is also shown that the asynchronous torque can be approximated by the classical equivalent circuit of an induction machine.