Torque performance enhancement of V-shaped interior permanent magnet synchronous motor by rotor shape optimization

Interior permanent magnet (PM) synchronous motor (IPMSM) has been used in many fields, such as the air conditioner, electric tool, electric vehicles, etc., due to their high efficiency, high power density and wide speed range. However, the torque distortion and high cost of PM materials has limited the application of the IPMSM. In this paper, a technique to enhance the torque performance and minimize the PM consumption by optimizing the rotor shape is proposed. The characteristics, including back electromotive force (EMF), cogging torque, and torque ripple, of the IPMSM with different rotor shapes are analyzed by using the finite element method (FEM). Moreover, the prototype with the optimal rotor shape is built and tested, and the results show the good agreement between the FEM analysis and the tested value.