This paper conducted a research on the electric powertrain system of a pure electric vehicle based on Automatic Transmission (AT).Through matching of the electric powertrain system and economic shifting control strategy of the AT optimized from the efficiency MAP of motor, the common used working points of the motor was optimized within its high efficient area. The conflict between vehicle dynamic performance and optimized economic performance was effectively overcome. Simulation results showed that the efficiency of electric powertrain system based on AT was higher than the single ratio electric powertrain system in general running cycles. The economic performance and the range of the vehicle were effectively improved.
