Study On Control Strategy Of Electric-Hydraulic-Compound Regenerative Braking For Pure Electric Van Carrier

Automobile,as a type of transport,is indispensable in today’s world.However,with the rapid development of automobile industry and the ballooning of consumers year by year,the problem of environmental pollution and energy shortage is becoming increasingly prominent.Electric vehicles have obvious advantages in saving energy and improving the environment.In recent years,they have got great progress due to the gradual improvement of state policy and financial support and consumer awareness.But it is still limited by high initial cost and short mileage.That is why it is difficult to promote large-scale production and use.It has been a hot topic in the field of electric vehicle research that the regenerative braking technology can recover the original wasted braking energy and extend vehicle mileage.In this paper,a pure electric van driven by rear wheel is taken as the research object,and two key problems are studied,which are the formulation of compound regenerative braking control strategy and the secondary development of ADVISOR software.Firstly,the structure and working principle of regenerative braking system were analyzed.Meanwhile the factors related to energy recovery were expounded.The characteristics and working principle of motor and battery have been emphatically analyzed and it established the theoretical foundation for formulating control strategies.Secondly,the advantages and disadvantages about classical control theory were described.With the requirements of ECE brake regulations for N1 type vehicles,the braking force distribution scheme for front and rear wheels of vehicles was formulated.A fuzzy controller with braking strength,vehicle speed and battery SOC as input variables,regenerative braking ratio and output variables was established in order to a better braking performance and energy recovery efficiency of vehicles.The fuzzy control theory was used to solve the problem about secondary distribution in compound braking,including regenerative and friction braking force.Then the regenerative braking control strategy of pure electric van was determined.Finally,the shortage of simulation models provided by ADVISOR was pointed and a post drive simulation model was established.Then the SIMULINK simulation model built by electric regenerative braking control strategy designed in this paper was embedded into the simulation platform.Under the working condition of UDDS and NYCC,the simulation analysis and comparison between ADVISOR default control strategy and this paper’s control strategy were carried out.The results show that the proposed control strategy can effectively recover braking energy on the basis of ensuring the safety and stability of braking.