Optimal design of novel concentrated flux IPM type brushless DC motor

Abstract

This paper proposes a novel concentrated flux interior permanent magnet (IPM) type brushless DC (BLDC) motor that replaces low-price ferrite magnets, which has similar characteristics as the conventional IPM type BLDC motor that uses expensive NdFeB magnets. To minimize the cogging torque which is a disadvantage of the proposed model, optimal designs of rotor and permanent magnet were performed. In optimal design process, the Kriging method based on the Latin hypercube sampling (LHS) and a genetic algorithm (GA) are applied due to suitability to non-linear data. Furthermore, to improve the average torque of the proposed model, the current excitation range was changed according to inductance. Through the optimal design process and the proper current excitation range, we show that the optimal model using low-price ferrite magnets has similar performance as the conventional IPM type BLDC motor using NdFeB magnets.