Optimization design and analysis of a hybrid permanent magnet flux-switching motor with compound rotor configuration

Abstract

This paper proposes a type of flux-switching permanent magnet (FSPM) motor, where the design concept of the hybrid permanent magnets (HPM) and the compound rotor are incorporated into the motor design. In such design, the proposed motor can not only realize the significant reduction of NdFeB volume, but also artfully convert external magnetic flux leakage into the air-gap field to achieve competitive torque density and desirable PM usage efficiency. For extensive investigation, two topologies of the HPM are designed and analyzed for the proposed motor, which consist of the parallel-magnetic-hybrid (PMH) mode and serial-magnetic-hybrid (SMH) mode. To fully exploit the potential advantages of the proposed motor, a multi-objective optimization design is conducted, where the response surface method (RSM) and sequential non-linear programming (SNP) method are purposely utilized. After optimization, the electromagnetic performances of the motor with PMH mode and SMH mode are evaluated and compared by using finite element method (FEM), which include the back-EMF, cogging torque, output torque, and so on. Furthermore, the partial demagnetization of the ferrite PM is also investigated in the paper. Finally, the theoretical analysis and simulation study verify the effectiveness of the proposed motor and corresponding optimization design.