Research On Braking Energy Recovery Control Strategy Of Electric Vehicle

The promotion of electric vehicles plays a great role in saving energy and protecting the environment,but the short mileage of electric vehicles is a obvious problem,and energy recovery technology is an effective way to increase the mileage of electric vehicles.The energy recovery of electric vehicle braking is carried out through the participation of electric motor in braking,so the electric motor braking can recover energy more effectively under the premise of ensuring safety.The research content of this paper is to recover the energy more effectively by reasonably distributing the friction braking force and the electric motor braking force.The basic structure of the electric vehicle and the structure of the electric drive system of the electric vehicle and the structure of the energy recovery and braking system of the electric vehicle are first studied,and some factors affecting the energy recovery are analyzed.According to the basic parameters of the automobile,the parameters of the drive motor are matched by using the knowledge of the automobile theory,and a suitable motor is selected.And the distribution coefficient of the front and rear wheel braking force is analyzed according to the force of the ground on the front and rear wheels during braking.By the ECE Regulation,the front and rear axle distribution coefficients are defined when the electric vehicle is braked.Then several classical control strategies are learned and the control strategies of this paper are designed.The braking strength of the electric vehicle is optimized by the optimization algorithm,and the limit of the braking strength of the electric vehicle is obtained,which is mainly based on energy recovery or braking stability.According to the braking strength,the braking power of the front and rear axle of the electric vehicle and the proportion of the braking force and friction force of the electric motor of the driving wheel are distributed,and the control strategy of energy recovery in this paper is designed.Finally,simulink and cruise are used to simulate the designed control strategy.The whole vehicle model is established in Cruise simulation software.The braking energy recovery control strategy model of electric vehicle built in MATLAB/Simulink is imported into cruise for simulation.The simulation under NEDC and FTP75 workingconditions is carried out in cruise software,and the effect of energy recovery is obtained under both working conditions.