Optimal Power and Torque Control of a Brushless DC (BLDC) Motor/Generator Drive in Electric and Hybrid Electric Vehicles

In this paper, the advanced control methods to minimize torque ripple and to maximize power density of a brushless DC (BLDC) motor/generator system in electric vehicles (EVs) and hybrid electric vehicles (HEVs) are presented. A simple and straightforward torque ripple control method with copper loss minimization for BLDC machines is proposed first. Then, an optimal power control to maximize power density and minimize machine size and weight for non-sinusoidal BLDC machines is explained for generation mode of EVs and HEVs. Overall, the proposed approaches can improve the performance of a BLDC motor/generator system. Fundamental theory of the proposed methods is presented and the performance is demonstrated by simulations and experiments