Multi-material Structural Optimization of IPM Motor Using Phased Application of Density and Level-set Method

Abstract

Because the interior permanent magnet synchronous motor (IPMSM) is one of the most efficient motors, it is applied to many industrial machines. The electromagnetic characteristic of IPMSM is dependent on many design parameters such as the position and shape of flux barrier, the magnetization angle of permanent magnet, the current phase angle and so on. The topology optimization (TO), which is an attractive method due to the wide design range with high degree of freedom, has been applied to the rotor design of IPMSM. In this paper, two stage TO method is proposed. Firstly, to widely search the rotor structure, the density method (DM) which handling gray scale is carried out. Next, the obtained structure is set to the initial structure of level-set method (LSM), the local search is carried out. The performance of proposed TO method composed of DM and LSM is compared with the single TO method (DM or LSM) in the design problem in which the object is the determination of the rotor structure composed of permanent magnet, rotor core and flux barrier to improve the torque characteristics and the magnet demagnetization.