Research On Parameter Matching And Control Strategy Of Power System Of Pure Electric Vehicle

Under the background of increasing global environmental pollution,human beings pay more attention to environmental improvement.And the tail gas pollution problem of the traditional auto industry also caused great pressure to environment,a lot of auto demand and shortage of petroleum resources makes the problem is particularly prominent,so the development of new energy vehicles,especially the pure electric vehicles become the problem of dealing with the traditional auto industry's top priority,with the development of electric vehicle technology,instead of traditional auto industry has become an inevitable trend.The matching of power system parameters plays a key role in the performance of electric vehicles.Reasonable adaptation of motor power,torque,battery capacity and voltage,transmission ratio and other parameters can make pure electric vehicles achieve better performance.Based on the M21 pure electric logistics vehicle of hongxing automobile manufacturing co.,ltd.as the research object,this paper mainly aims at matching and optimizing the power system parameters.The matching contents mainly include motor selection and its layout design,and battery selection includes battery voltage and capacity calculation.The matching results were simulated.The simulation experiment in this paper used CRUISE software of AVL company to simulate the performance of the whole vehicle,and compared with the test data of real vehicle NEDC,so as to verify the accuracy of the simulation software.After the initial matching,the optimization scheme was designed for the existing scheme.From the simulation results of the initial matching and the verification results of the real vehicle,it can be seen that the vehicle still needs to be optimized in terms of power performance.The primary matching scheme is the direct drive mode of the rear motor without the involvement of the gearbox.The research shows that the pure electric vehicle based on the two-speed gearbox has certain improvement in economic performance and dynamic performance.In this paper,on the basis of two gears transmission optimize the gear ratio,the optimized scheme for using PSO(particle swarm optimization algorithm,using MATLAB language programming M optimization program,to the best combination of the optimized two gear ratio andvalidated using the CRUISE simulation software to optimize the results,the results show that the vehicle performance in speed ratio on the performance of the improved after optimization.In order to further improve the economy of the vehicle,an optimal braking force allocation strategy with variable proportion is proposed in this paper.In ECE regulations of ideal braking force curve,M,f I curve of the range of allowable safety,based on the front and rear wheels braking intentions made the braking force distribution strategy,and the use of MATLAB/Simulink software structures,energy recovery strategy model,makes the braking energy can get maximum recycling,finally also CRUISE simulation software and CRUISE the default brake recycling comparing,this paper,the effect of the brake energy recovery strategy is verified.