Research On Regenerative Braking Energy Control Strategy For Pure Electric Vehicle

Pure electric vehicles have become most important ones for the automobile industry in various countries because of their advantages in many aspects such as cleanliness,environmental protection,low noise,diversified energy sources,and high energy efficiency.The regenerative braking technology is one of the energy saving and environmental protection technologies for the development of pure electric vehicles.It can realize the reuse of energy and can effectively extend the mileage of vehicles.With the maturing of battery and motor technologies,the application of regenerative braking technology to pure electric vehicles can be further promoted.Pure electric vehicles have different brake systems from traditional car brake systems due to the participation of motor braking.The electric vehicle braking system is composed of regenerative braking system and mechanical braking system.How to ensure that the vehicle properly distributes regenerative braking and mechanical braking so as to recover braking energy as much as possible under the premise of braking safety and comfort,which has become the key to studying regenerative braking technology.In order to solve this problem,the subject mainly aims to ensure the safety and comfort of the vehicle,and to recover braking energy as much as possible.The research on the regenerative braking control strategy of the pure electric vehicle is studied to make regenerative braking and mechanical braking betterly coordination of work.This paper introduces the purpose and significance of this paper,and analyzes the basic structure and working principle of the regenerative braking system for pure electric vehicles.The permanent magnet synchronous motor is taken as an example to introduce the feedback braking status of the motor.The restraint condition of braking energy recovery and common braking modes are analyzed in detail.According to the researched target vehicle models,the parameter matching of the motor and the battery is completed.Based on the analysis of the dynamics in the braking process of the pure electric vehicle and the analysis of the typical braking control strategy,an improved brake force distribution scheme of the subject is proposed.Based on the premise of braking safety and comfort,a fuzzy control strategy aiming at recovering braking energy as much as possible is completed,and the design of the fuzzy controller is completed.The AVL_CRUISE vehicle simulation platform was used to build a prototype vehicle model of a pure front-wheel-drive vehicle,and a control strategy model was built using MATLAB/Simulink.The vehicle model and control strategy model were co-simulated.The braking distance is selected as the evaluation index of braking safety,the maximum braking deceleration is used as the evaluation index of braking comfort,and the braking energy recovery rate is used as the evaluation criterion of regenerative braking.Three types of typical urban working conditions and typical braking conditions are selected and implement simulation.The simulation results show that the braking force distribution strategy based on fuzzy control can meet the design requirements under medium and low speed and medium and small braking intensity.In the case of high-intensity and high-speed,the brake safety is weak and the brake comfort is low;Finally,an adaptive neural fuzzy control is proposed to optimize the fuzzy control membership function.The simulation analysis of the braking distance,maximum braking deceleration and braking energy recovery.The results show that the optimized control strategy can meet the design requirements of this article and has a certain practical value.