Study On Ev Transmission System Parameter Design Based On Vehicle Dynamic Performance

The optimal design of the electric vehicle (EV) transmission system parameters is of great significance to the vehicle dynamic performance. In this paper, we analyse the vehicle acceleration process as well as the vehicle gradeability, based on which we determine the electric motor peak output power and the vehicle rated speed. Besides, we look into the correlations between the power-to-weight ratio, the constant-power-expanding coefficient and the reduction ratio range of the transmission system. According to these correlations, we propose an approach to selecting the transmission system speed reduction ratio. Furthermore, we optimise the parameter design done in previous steps by taking into account the actual motor maximum torque characteristic. Simulation results demonstrate that the proposed parameter design and optimisation methods significantly enhance the vehicle dynamic performance.