Research On Energy Recovery Control Strategy Of Electric Vehicle Braking

With the increasingly serious environmental pollution and energy crisis, new energy vehicles have become the hot spot of research in the world. Related studies shows that,vehicles running in urban conditions, consumed a lot of energy, because of the frequent braking and starting. If it is possible to recover the energy consumed in this part of the brake,then the energy utilization of the vehicle and the mileage of the vehicle will increase greatly.Therefore, the new energy vehicles are all loaded with brake energy recovery system.In order to improve the recovery rate of energy to extend the drive range. Firstly, the regenerative braking system of the pure electric vehicle is adjusted, new system used the electronic mechanical brake(EMB) instead of the traditional hydraulic mechanical brake. The electronic mechanical braking system is not only simple in structure, but also have fast response of braking time, these advantages will provide a better comfort for the regenerative braking system.The braking force distribution of regenerative braking system has an important influence of braking energy recovery and braking safety and stability. This paper will do a research on the braking force distribution for the regenerative braking system of electric vehicle. A control strategy based on EMB and EBD is proposed. Related control strategy model of braking force distribution is established in Matlab/Simulink, and the control model is simulated and analyzed.Simulation results show that, under mild braking condition, when the braking force of the demand is less than that of the motor regenerative braking force, the braking force of the vehicle is completely produced by the motor braking system. The higher the initial braking speed of the vehicle,the more regenerative braking energy recover. Under moderate braking condition, when the demand is greater than the braking force provided by the motor, the braking force of the whole vehicle is provided by the mechanical braking and motor braking,through this process, brake energy recovery is reduced compared to mild braking condition.When severe emergency brake, the energy recovery rate is zero, as this time the motor brake has been completely out of, only the mechanical braking participate in the braking of the vehicle. On the low adhesion road,such as wet slippery road surface, the control strategy processed avoided the driving wheel locked, so, compared to the optimal control strategy has higher energy recovery.