Comparison of electromagnetic performance of twelve-phase permanent magnet synchronous motors with different phase shift angles

The usual engineering modelling methods for multiphase motors are complex and computationally time consuming. In this paper, the torque pulsations and other basic electromagnetic properties of twelve-phase surface-mounted permanent magnet synchronous machine with phase shift angles of 15° and 30°, respectively, are calculated using an analytical computational method based on the exact subdomain model approach. Calculations include air-gap flux density, electromagnetic force density, cogging torque and electromagnetic torque, which are verified using finite element analysis. The comparisons show that the torque pulsations of the motor are smaller at a phase shift angle of 15°, and the results obtained by the analytical method are accurate and take much less time than the finite element analysis.