OPTIMUM DESIGN CONSIDERING MAIN OPERATING POINTS OF EV TRACTION MOTOR FOR TORQUE RIPPLE REDUCTION AND FUEL ECONOMY IMPROVEMENT

Abstract

In this paper, the optimum design considering main operating points (MOPs) of the electric vehicle (EV) traction motor is conducted to reduce the torque ripple and improve the fuel economy. MOPs of the traction motor can be determined by considering ratios of number of operating points or considering energy consumption ratios based on the EV simulation. Specifically, the optimum design is conducted with the aim of minimizing the torque ripples at MOPs determined by considering ratios of number of operating points (RNOMOPs) and maximizing the inverter-motor system efficiencies at MOPs determined by considering energy consumption ratios (ECRMOPs) to simultaneously reduce the torque ripple and improve the fuel economy. To verify the effectiveness of the optimum design considering MOPs proposed in this paper, torque ripples at RNOMOPs and the fuel economies according to the initial model and the optimum model are compared. As a result, torque ripples of the optimum model at RNOMOPs are remarkably decreased by 58.84 %p and 57.77 %p, respectively, and the fuel economy according to the optimum model is improved by 1.72 %. Conclusively, the effectiveness of the optimum design considering MOPs of the EV traction motor for the torque ripple reduction and the fuel economy improvement is verified.