Parameter Matching And Simulation Optimization Of Power System Of A Pure Electric City Bus

In today's society,industrial technology is developing rapidly,especially in the automotive industry.When people enjoy the convenience brought by the vehicle,they are also deeply immersed in a series of problems such as lack of energy and exhaust pollution caused by the car.Therefore,a new type of clean,environmentally friendly,pollution-free pure electric vehicle came into being.In particular,the development of pure electric city buses has been greatly promoted and supported by government departments.Since most of the pure electric city buses are driven in towns and cities,the requirements for the maximum speed are low,and at the same time,the internal space is large,and a large-volume,large-capacity battery can be placed to meet the driving mileage requirement.In addition,the city bus has its own fixed driving line,which is convenient for the installation,maintenance and maintenance of the charging pile.Therefore,pure electric city buses are gradually getting a lot of applications and promotion in various provinces and cities.The topic of this thesis comes from a company's "12m pure electric city bus research and development" project,which matches the powertrain parameters of the target model and optimizes its transmission system transmission ratio.Firstly,the analysis of the kinematics characteristics of pure electric vehicles is carried out,and the economic,dynamic and cost requirements are analyzed.On this basis,the main components of the power system,including the drive motor,power battery and transmission,are based on the vehicle performance index.For more details,perform detailed matching calculations and selection.Secondly,using ADVISOR software platform,the whole vehicle simulation model of pure electric city bus is built,which mainly includes the main reducer,power battery and drive motor and wheel and other component models,and set calculation tasks such as acceleration and climbing,and carry out simulation calculation.Analysis of the simulation results,found that the maximum speed does not meet the performance requirements,in order to meet the requirements of the vehicle specifications,the drive train transmission ratio needs to be further optimized to improve the economy and power of the vehicle.Subsequently,a global optimization method based on the joint simulation optimization mechanism is proposed.The joint simulation optimization platform is established by using ADVISOR and ISIGHT software,and the optimal solution of the drive train ratio is found in the feasible domain through global search.The optimized transmission ratio is brought into the built vehicle simulation model,and compared with the simulation results before optimization.It was found that the maximum speed of the vehicle increased by 5.3%,and the speed of 40km/h continued to increase by 7%.The results of other aspects also met the requirements of the vehicle performance index.Finally,the 12 m pure electric city bus prototype will be tested according to the national test standards and methods,including economic test and power test.The test results are compared with the simulation results.The test results show that the economy and power of the vehicle can meet the performance requirements of the target vehicle.The overall optimization of the transmission system transmission ratio through joint simulation can effectively improve the vehicle performance of the vehicle.The rationality and effectiveness of the matching of pure electric city bus parameters and the joint simulation optimization of the transmission ratio are verified.