Research On Regenerative Braking Control Strategy Of Pure Electric Vehicle

Regenerative braking technology is one of the key technologies to improve the mileage of electric vehicles.It can convert part of kinetic energy into electrical energy by motor reversal in the process of braking or deceleration,ensuring the safety of braking at the same time,to achieve energy recovery and generate partial power.It's zero emissions and no pollution,as well as improving the fuel economy of the car.Studying on a pure electric vehicle modified by a domestic pioneer cart in this paper.The purpose is to realize the maximum recovery of electric vehicle braking energy without increasing the auxiliary device.Therefore,the core of this paper is to study the control strategy of regenerative braking.Solving two major problems in regenerative braking control strategy.First,how to allocate the power of the front and rear axles reasonably,so as to ensure the stable and reliable braking.Second,how to allocate the power of the front axle fluid and motor braking force,so as to maximize energy recovery.The structure and working principle of regenerative braking system and ABS hydraulic braking system are briefly introduced in the beginning.According to the braking dynamics model of electric vehicle,the process of hydraulic braking force and motor braking force is analyzed.Three control strategies are set.Adhesion coefficient and ABS factors are added into the parallel strategy and the serial strategy.Based on ECE rule line,the maximum energy recovery braking force distribution strategy is proposed.Motor braking force and hydraulic braking force of the front and rear wheels in the three control strategy are calculated in detail.Using the AMESim simulation platform to establish motor regenerative braking system model and ABS hydraulic brake system model.Eight kinds of working condition are selected to simulate and compare the three control strategies.The braking performance,directional stability,energy recovery rate are used to evaluate the braking performance of the three control strategies at last.The simulation results show that,under the emergency braking conditions,three kinds of control strategy can meet the braking safety requirements without energy recovery.The braking efficiency of the series strategy is optimal,and the maximum power allocation strategy is the second.In an emergency braking condition,braking efficiency of themaximizing strategy and the series strategy was less than that of the parallel strategy.However,the energy recovery rate of the maximizing strategy and the series strategy is significantly higher than that of the parallel strategy,and the optimal power allocation strategy is the best synthetically.