Research On Key Technologies Of Electro-hydraulic Composite Braking System For New Energy Electric Vehicles

In the current environment,new energy electric vehicles have achieved some development achievements,but at the same time they have exposed a series of development bottlenecks.the problem of short range of electric vehicles is more prominent.Regenerative braking refers to the process in which new energy electric vehicles use the characteristics of their driving motors to recover braking energy and store part of their kinetic energy with other forms of energy.This will not only help to increase the range of electric vehicles,but also reduce the cost of car owners.However,considering the strength and energy recovery efficiency of motor braking and the safety requirements of braking regulations,the traditional hydraulic mechanical system still needs to be retained.This involves a new type of mechanical hydraulic braking system which is redesigned and matched for electric vehicles,so that it can work in coordination with the motor braking system,with normal braking performance,while recovering braking energy,and improving vehicle mileage.Therefore,this paper takes a new energy electric vehicle under development as the research object,designs the electro-hydraulic composite braking system for it and studies the electro-hydraulic composite braking system.The main work is as follows.1.Based on the advantages and disadvantages of the existing mechanical hydraulic braking system,an electro-hydraulic composite braking system suitable for the application of new energy electric vehicles is proposed.2.The dynamic analysis of the working process of automobile braking is carried out,and the corresponding principle of regenerative braking is expounded.After analyzing the existing optimal energy recovery braking control strategy,parallel braking control strategy and optimal braking effect braking control strategy,a suitable braking force control strategy is proposed.The proposed braking force control strategy can not only ensure the braking performance but also recover more braking energy under the premise of meeting the corresponding braking regulations.3.The whole vehicle model except braking system is built in Carsim software.The braking system and corresponding braking control algorithm are modeled under the environment of Matlab/Simulink,and the joint simulation model of Carsim and MATLAB/Simulink is built.4.Based on the joint simulation model,the NEDC cycle and emergency braking conditions are selected to verify,and the key parameters are monitored to verify the design of the electro-hydraulic composite braking system.The results show that the electro-hydraulic composite braking system works normally and has feasibility.At the same time,the braking performance and energy recovery performance of the braking system reach the design goal.In this paper,the scheme design and theoretical analysis of the electro-hydraulic composite braking system are carried out,and the control strategy of the braking system matching the design scheme is put forward,and the model and Simulation of the designed electro-hydraulic composite braking system are carried out.The research results provide theoretical basis and simulation cases for the further study of the electro-hydraulic composite braking system of new energy electric vehicles,and have great engineering application value for the further development of the electro-hydraulic composite braking system.