关键词: 车辆工程；纯电动汽车；双电机驱动；驱动系统效率最优；参数匹配

Abstract: How to determine the motor working mode and ensure that both motors work in the working range with the optimal efficiency is the focus of the research on the power transmission system of pure electric vehicles with double motors driven. Aiming at the pure electric vehicle driven by dual motor coupling, the powertrain parameter matching design was carried out, and the control strategy of power transmission was proposed based on the principle of optimal efficiency. Firstly, according to the dynamic requirements of the target vehicle, the parameter matching design of the motor and battery of the power system was carried out, and the simulation model was established by CRUISE software to simulate and verify the maximum speed and climbing performance of the vehicle. Then, according to the driving efficiency of power transmission system, the optimal working point of motor was solved by sequential quadratic programming optimization algorithm, and the multi-mode switching dual electric power distribution control strategy was proposed. Finally, a co-simulation model was established to verify the proposed efficiency optimal control strategy. The results show that under the optimal control strategy of transmission system efficiency, the power performance and economy of the whole vehicle are improved, and the energy utilization rate is better. Under the typical cycle conditions of WLTC, the average efficiency of the dual motor coupling drive system is 85.9%. And the motor working point with the efficiency of the drive system greater than 85% accounts for 55% of the whole working range, and the dynamic performance of the vehicle is improved. The research can provide a theoretical basis for the design of power transmission system and the research of control strategy of pure electric vehicle.

Key words: vehicle engineering; pure electric vehicle; dual motor drive; driving system optimal efficiency; parameter matching