Optimization And Co-simulation Of Pure Electric Bus Power System Parameters

Since conventional cars exacerbate the worldwide energy crisis and environmentalcrisis with consuming large amounts of oil, the development of the traditional auto industrywill face a huge challenge in the future. In order to deal with these problems, manygovernments, enterprises and research institutions are devoting themselves to the researchof new energy vehicles, and try their best to minimize or avoid the consumption of oil andthe emission of harmful gases. Electric vehicles use electricity to supply drive force withhigh energy efficiency, low emission, low pollution, etc., and therefore they are favored bymany researchers and have broad prospects for future applications. Pure electric bus has alarge interior space, and its maximum speed is relatively low, so it can carry morebatteries, the layout of the battery pack is also more convenient, thus its driving range isrelatively long. In addition, due to its operating routes is always fixed, it’s easy for it to useand maintenance, so the pure electric bus is more conducive to the promotion andapplication of market-oriented. At this stage, pure electric bus is leading to other types ofpure electric vehicles in many areas of technology, and it will become a pioneer in thepopularity of electric vehicles in the future.The purpose of this paper is the parameter optimization and co-simulation of the pureelectric vehicle power system. It mainly relies on pure electric vehicle of the keytechnological project of Shaanxi Province-pure electric vehicle test car, and use“LS6600C1” medium-sized bus as the platform to modify the test vehicle. Through theestablishment of vehicle dynamics model, battery model, super capacitor model, motormodel, model of the drive train, wheels model, and a combination of vehicle model witheach part of the models. Then combined with the power and economy of the vehicle designspecifications, match the design of the vehicle’s power system parameters. Afterpreliminary matching the power system, with the transmission gear ratio as the optimizationvariables, and with the speed up time and specific energy consumption as the objectivefunction, optimize design parameters for power system using improved NSGA-II multi-objective genetic optimization algorithm, to make it meet the dual goals requirementsof the power and economic; Finally, combination of MATLAB’s powerful modelingcalculation function and VC++’s good human-computer interaction interface, we designinterface of Visual C++and MATLAB based on MATCOM, to achieve Visual C++withMATLAB joint programming, and use the combination of the two programming to achievethe simulation of pure electric vehicle power system, and design the simulation programinterfaces based on VC++to simplify the operation.The co-simulation results show that: through matching and optimization of theparameters of the power system, the maximum speed and acceleration performance of pureelectric passenger car has been improved, while its driving range has been increasedcompared with the reduction of energy consumption. So the bus’ power and economicindicators have both been improved, And it can verify that the optimization method isreasonable, and it will also provide important guidance for the matching optimization ofpure electric vehicle power system parameters in the future.