Research of interior permanent magnet brushless DC motor for electric vehicles

Permanent magnet brushless motors for electric vehicles are presently given an increasing attention. With this trend, this paper deals with an interior permanent magnet (IPM) brushless DC motor (BLDCM), which is supposed to apply in a two-seater pure electric car. Firstly, the performance indicators of the motor were determined according to the power requirements of the car at different driving speed, and a 10kW IPM-BLDCM was designed preliminarily. Then, choosing air gap length, permanent magnet thickness and the number of stator winding turns as variables, parametric analysis was made to research the influence of structural parameters on system efficiency and the torque-current ratio. After an optimization design, a prototype was fabricated and tested. The test results show that the optimized prototype can meet the need of the driving system both in constant torque region and constant power region.