Hybrid Excitation PM Synchronous Motors: Part II — Finite Element Analysis

This paper deals with the finite element analysis of Hybrid Excitation Permanent Magnet Synchronous Motors, that is, synchronous motors characterised by a rotor including both permanent magnets and an excitation winding. Such a winding is adopted to modulate the rotor flux so that the motor exploits the maximum torque for any operating speed. The higher benefit is obtained at speeds higher than the nominal speed, i.e. during the flux weakening operations. Thus the focus is to determine the performance of different topologies of hybrid excitation PM synchronous motors, considering compared to those achieved with a standard interior PM synchronous motors. The possibility to vary the rotor flux in the hybrid excitation PM motors allows to design the motor with a high no-load flux linkage, necessary to get high torque at low speeds, and to get high torque in a wide speed range.