Finite Element Analysis of Hybrid Type Permanent-Magnet Synchronous Motor at Asynchronous Operation

Abstract

This paper describes a finite element analysis of hybrid type permanent-magnet synchronous motors at asynchronous speed. In this analysis, any instantaneous operating point of permanentmagnet, eddy current and magnetic saturation in the rotor are considered. First, the authors propose a simple analytical model in which the rotational motion of the rotor is considered. Secondly, asynchronous operating characteristics are analysed by using this analytical model and the finite element analysis when the terminal voltage is given. In order to explore the effect of the magnet magnetization on asynchronous performance, the motor characteristics of the case that no magnetization exists in permanent-magnets, are considered. In this case, an agreement between calculated and measured values of input currents for experimental motor is good. Therefore, it is made clear that this analysis is reasonable. Lastly, the average and pulsating torques, and the braking torque caused by the permanent-magnets at asynchronous speed, are determined quantitatively.