Multi-objective optimization of an Interior PM motor for a high-performance drive

Abstract

This paper shows the results of the optimization of an Interior Permanent Magnet (IPM) motor for a high performance drive. A multi-objective is considered in the optimization process, mainly considering two motor capabilities. The first objective is the maximization of the torque density of the motor. This means that the torque is maximized for given external dimension and for given current density (i.e., given electric loading). The second objective deals with the sensorless detection of the rotor position. A technique based on the high-frequency signal injection is considered. The IPM motor has to keep the capability to be sensorless detected when it works at any load. In particular, such a capability has to be verified along the trajectory of the Maximum Torque per Ampere (MTPA), that is, the rotor has to exhibit a proper differential saliency (typically not lower than two) along all the MTPA trajectory, including overload operating conditions.