Optimal Design of Rotor Slot Geometry to Reduce Rotor Leakage Reactance and Increase Starting Performance for High-Speed Spindle Motors

Abstract

This paper proposes optimal designs of three closed rotor slots geometries for reducing the rotor leakage reactance and increasing the starting performance of high-speed spindle motors. The optimal designs were developed using the response surface methodology and Finite Element Method (FEM). Three closed rotor slot geometries, namely closed, round, and oval were investigated through FEM calculation and validated by experimental measurement for improving starting performance parameters such as starting current, starting torque, magnetic flux linkage in starting condition, and efficiency. In this study, a starting performance analysis, including the alternative equivalent circuit method and flux linkage FEM analysis, was employed. The results show that among the three slot geometries, the optimal design of the circular closed rotor slot produces the lowest rotor leakage reactance and the highest magnetic flux linkage, starting torque, and efficiency. A comparison between the simulation and experimental results validated the accuracy of the proposed model with percentage error being approximately 8%.