Multi-objective Optimization Of Braking Stability And Braking Energy Recovery Of Pure Electric Vehicle Based On EMB

With the deterioration of the environment and the consumption of energy and the emission of harmful substances,new energy electric vehicles have become one of the most important targets of the state.The vehicle will consume a lot of energy in the braking process,while the regenerative braking energy recovery system of pure electric vehicle has no energy consumption,which can greatly reduce vehicle emissions due to energy consumption.The electro mechanical braking system has the following advantages: simple structure,fast braking response,high braking efficiency and high sensitivity,and it can be easily controlled with other systems.The distribution unit of braking force is composed of electronic control units,which can distribute reasonable braking force according to the braking requirements.The wheel motor technology directly generates the braking torque through the independent control of the wheel drive,which reduces the complexity of the control system and improves the accuracy and timeliness of the reaction.The super capacitor has strong current discharge capacity and high power,which together with the battery,to constitute the double energy system which can give full play to the super capacitor power and battery specific energy advantages,also to meet the needs and characteristics of the electric vehicle specific power,specific energy.This paper combines the EMB braking system,wheel motor regenerative brake system and characteristics of super-capacitor and battery energy storage system,putting forward a kind of electric vehicle in different braking intensity under the optimal power allocation method to improve the braking stability and braking energy recovery rate of pure electric vehicles.In this paper regarding the electric vehicle braking stability and braking energy recovery rate as the optimization goal,and regarding the braking force distribution coefficient,regenerative torque,battery / super-capacitor of the upper and lower limit value of SOC as the design variables,multi-objective particle swarm optimization algorithm is used in multi constraints to obtain the Paretro optimal solution set,so as to achieve the optimal allocation power system.Building the system models of the EV based on Simulink platform,then the optimization result parameters is inputted to the ADVSIOR platform.With simulating the ECE,NYCC and UDDS to simulate it,then the simulation of these three cases the results are analyzed,and the regenerative braking control strategy of traditional auto method,artificial neural network control strategy of the brake force distribution,genetic algorithm optimization and control strategy were compared,contrasting the relationship between adhesion coefficient and braking strength before optimization and after optimization finally.The results show that the pure electric vehicle braking energy recovery and braking stability can be improved obviously,so the power distribution system of different method of optimal braking strength so proposed under the complex electric vehicle system with EMB,hub motor,super capacitor and battery optimized after simulation modeling,which can effectively improve the vehicle braking energy recovery and regeneration braking stability.