| Environmental pollution and energy shortage are becoming more and more serious.In order to solve these two problems more effectively,all industries take environmental protection and energy saving as the direction and goal of further development.The promotion and development of new energy vehicles in the automobile industry is one of the effective ways to solve these two problems,among which pure electric vehicles are the most widely used.However,some technical problems have not yet been solved,which limits the development of new energy vehicles.For example,the slow development of energy storage technology leads to the lack of driving range,which has become a major obstacle to the development and popularity of pure electric vehicles.The hybrid power supply composed of batteries and super-capacitors can effectively improve the driving range and power performance of vehicles.Hybrid power travel distance can effectively improve the vehicle and the vehicle energy utilization is the key to the application of the braking energy feedback technology,but at present the application of the braking energy feedback technology is still not mature enough,therefore,based on the hybrid power research brake feedback technology can further improve braking energy feedback efficiency and vehicle utilization,improve the travel distance of vehicle.In this paper,the proposed hybrid power energy storage system as the research object,in order to improve the braking energy feedback rate and energy utilization rate of the vehicle as the goal,research a braking energy feedback control method.Relevant research has been carried out from the following aspects:（1）Research on electric vehicle energy storage components and energy storage system.The characteristics and application of electric vehicle energy storage technology are analyzed,and the advantages and disadvantages of each energy storage technology are compared.In this paper,a hybrid power supply and its control strategy are proposed to ensure that the energy storage system of electric vehicles has the characteristics of high energy density and high power density at the same time,so as to meet the requirements of vehicle driving range and power.（2）Research on braking energy feedback control system.The working principle of braking energy feedback system and influencing factors of braking energy feedback efficiency of electric vehicle are analyzed.Three typical braking force distribution control strategies were studied and compared from three aspects of the strategy’s implementation difficulty,braking stability and braking energy feedback efficiency.（3）Research on braking energy feedback control strategy.By analyzing the braking force of pure electric vehicle,the braking force distribution control strategy of front and rear axles was designed based on I curve and ECE curve.Based on logical threshold control,fuzzy control algorithm and particle swarm optimization algorithm,three mechanical/electric braking force distribution strategies of front axle were designed.（4）Experimental and simulation verification.The simulation models of hybrid power control strategy and braking energy feedback control strategy proposed in this paper were established in MATLAB/Simulink.Based on the designed vehicle parameters,the vehicle model was established using AVL CRUISE,and the vehicle model was co-simulated with the control strategy.Simulation analysis is carried out under braking conditions of different intensity as well as NEDC,CLTC and FTP75 cycle conditions.The simulation results show that the hybrid power proposed in this paper can effectively reduce the working pressure of the battery,and the braking energy feedback control strategy can significantly improve the energy feedback efficiency while ensuring the braking stability.The effectiveness of the proposed control strategy is verified. |
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