Study On Economic Driving Strategy Of Pure Electric Vehicle

With the increasing depletion of petroleum resources and the increasing demand for energy saving and emission reduction,environmental protection has become increasingly important.The automotive industry is changing from fuel to electricity.Compared with traditional fuel vehicles,electric vehicles have the advantages of simple structure,zero emission and high efficiency.Especially at present,with the rapid development of intelligent network combined vehicle and unmanned driving technology,the control of more simple and accurate electric vehicles has greater advantages.However,at present,the short range of pure electric vehicles has become the most important factor restricting its development.This paper takes a pure electric vehicle as the research object,aiming at reducing energy consumption,studies the economic driving control strategy of electric vehicle.Firstly,the vehicle longitudinal dynamics model and the power system model are established.In the power system modeling,the research goal of economic driving strategy is fully considered.The model is simplified effectively.Then,based on the research object and the model,the acceleration control strategy is discretized into the selection of the torque at each speed by means of discretization based on efficiency MAP diagram.The greedy algorithm is adopted to solve the economic strategy based on the energy consumption of equal distance driving,which satisfies the real-time requirement of practical application.The applicability of the greedy algorithm is verified by comparing it with the dynamic programming algorithm.In the case study,it is pointed out that the main solution of economy is the balance between driving resistance,especially wind resistance and power system efficiency.In comparison with no acceleration distance limit,the economic strategy can achieve about 10% energy-saving effect compared with the rapid acceleration.Compared with the uniform acceleration strategy,the economic acceleration strategy can achieve a maximum of about 3% in the comparison with the acceleration distance limitation.Aiming at cruising conditions,the reason why the economic speed of pure electric vehicle is lower than that of traditional fuel vehicle under constant cruising speed is that the efficiency of power system is higher as a whole,and the cruising economy is greatly affected by wind resistance.In the cruise strategy of "Acceleration-taxiing"(PnG),the control strategy of accelerating with the highest efficiency of power systemis put forward by analyzing its energy-saving characteristics.Compared with the energy consumption of constant speed cruise,this strategy can achieve 7%-8%energy saving effect at medium and low speeds.At the same time,it is pointed out that the reason why the energy saving effect decreases at high speeds is that the increase of load demand of high speed cruise improves the economy of constant speed cruise,thus reducing the energy saving effect of PnG strategy.Finally,through the comparison of ADVISOR simulation software,the simulation verifies the accuracy of the discrete solution method and the universal applicability of the economic driving strategy.