Computer aided design of permanent magnet brushless DC motor for hybrid electric vehicle application

This paper deals with a method of design of permanent magnet brushless dc machine (BDCM), primarily aimed for hybrid electric vehicle applications. The design variables such as airgap flux density, slot electric loading, stacking factor, coil fill factor, end turn coil factor, magnet fraction, slot fraction, flux density in the stator back iron, etc., are used in design process. The simplified design equations for trapezoidal back emf motor of rating 16 hp (12kW), 1100 rpm, 72 V radial flux surface mounted BDCM are obtained and used for CAD algorithm which gives the calculated performance of the motor. Since the motor is for high current and low voltage application so water cooling is used. Sequence Quadratic Programming Technique is used as a constraint optimization tool to achieve feasible and acceptable design. Finite element analysis are then carried out to obtain the electromagnetic characteristics of the motor for modification and verification of the obtained computer aided design.