Research On Energy Management Strategy Of Dual Motor Driving Electric Vehicle

With the increasing shortage of energy and environmental pollution,pure electric vehicles have attracted widespread attention due to their advantages of zero-fuel consumption,zero pollution,and zero emissions.Because of the traditional single motor configuration pure electric vehicle in the low load condition,the motor work efficiency is low,resulting in the increase of the energy consumption.In addition,for the drive motor of the matching mechanical automatic transmission,there is a problem of power interruption in the shifting process.In this paper,two kinds of dual motor configurations driving system with high energy saving potential and avoiding power interruption are proposed.This paper carries out research work from the following aspects:(1)Optimization of transmission parameters of transmission system.Through the given vehicle parameters,battery and related parameters of the drive motor,to meet the dynamic requirements of the vehicle while increasing the economic efficiency as much as possible,the vehicle model is built based on the Matlab/Simulink platform,and using the dynamic programming algorithm to offline optimize transmission gear and speed ratio,to determine the best transmission parameters.(2)In this paper,two kinds of driving system with two motors are proposed,and the rule-based control strategy is developed.For the traditional single-motor type drive system with high energy consumption under low-load conditions,two kinds of electric vehicle dual-motor type drive systems are proposed after analyzed.By analyzing the characteristics of typical cycle conditions and the complete vehicle dynamics requirements,match the parameters of the drive motor,and then combining the performance parameters and efficiency characteristics of the drive motor to formulate a rule-based energy control strategy,that is to say,the shift control strategy of the transmission and torque distribution control strategy are determined,after the simulation under a variety of cycle conditions,the energy saving mechanism of dual motor configurations are analyzed.(3)The dynamic programming algorithm is used to optimize the control strategy of dual motor configuration drive system,and further reduce the energy consumption of the vehicle.Taking the state of charge(SOC)of the battery as the state variable,taking the torque distribution ratio of the two motors and the gear position of the transmission as the control variables to achieve the goal of minimizing the power consumption of the system,an optimization model of dynamic programming algorithm was built based on the Matlab/Simulink platform.The related parameters of the original rule-based energy management strategy were optimized offline.Finally,using the optimized control strategy to simulate the energy consumption under different cycle conditions,the results show that the optimized control strategy is further improved.(4)The reliability of the rule-based energy management strategy is verified.Based on the Matlab/Simulink software platform,the vehicle model and control strategy model were built,and the hardware-in-the-loop(HIL)experiment platform was built based on dSPACE.The reliability of rule-based energy management strategy was verified by on-line real-time simulation.