Optimal design of five phase permanent magnet assisted synchronous reluctance motor for integrated starter generator application

This paper presents the design of optimal five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM) for integrated starter generator (ISG) application. PMa-SynRM is the hybrid structure of interior permanent magnet (IPM) motor and synchronous reluctance motor (SynRM). In this study, an optimized 15kW five-phase PMa-SynRM has been proposed as a better substitute for three-phase IPM motor for ISG operation in Honda Civic Hybrid car. A new reverse engineering technique (RET) has been applied to model the Honda IPM ISG. In order to develop a better PMa-SynRM ISG, the model developed using RET has been used as reference. Thorough analytical and finite element analysis have been performed to obtain the optimal PMa-SynRM design which has better performance characteristics compared to the Honda IPM ISG. Lumped parameter modeling (LPM) has been utilized with differential evolution (DE) optimizer to extract the best optimal design for the five-phase PMa-SynRM ISG. For the same power and volume, five-phase PMa-SynRM design has shown better performance characteristics in terms of cogging torque and torque developed.