Research Of Battery Management System Of The New Energy Vehicle

Battery,motor and electronic control are the core technologies of new energy vehicles.The energy supply of electric vehicles is mainly provided by batteries.The proportion of battery cost is very high,and battery system is the main embodiment of automobile performance.In order to maximize performance of the battery system,improve its efficiency and life,and at the same time ensure the driving safety of the vehicle,it is very important to conduct comprehensive research on battery management system(BMS).The dissertation relies on a "fuel cell car industrialization project" for power battery management system research and development.Firstly,based on the fuel cell power system parameters,simulation calculation was carried out to confirm the requirements of the battery system.Then battery cell was selected and the battery system structure was determined.With the analysis of the functional requirements and electrical architecture of the fuel cell car,a master-slave distributed was proposed and designed.In order to ensure product reliability and research efficiency,the key technologies of BMS was selected and improved based on more mature and reliable methods in engineering applications and the characteristics of the fuel cell power system.For SOC estimation,an improved algorithm integrating the advantages of ampere hour integration method,OCV method and internal resistance method was proposed;For SOP estimation and battery equalization,the engineering reliable method was selected,and various experiments have been carried out to verify the effectiveness of above results.In terms of hardware exploitation,several important structural designs were implemented,including core processor circuit,CAN communication circuit,insulation resistance detection circuit,high-voltage interlock circuit,total voltage acquisition circuit,total current acquisition circuit,thermal management control circuit,and high-voltage executive part control circuit.Through software design,functions such as system state conversion,charge and discharge control management,high-voltage interlock,insulation detection and data acquisition were realized.A unique "passive equalization fault detection circuit" patent technology was added to the equalization circuit in order to solve the problem of failure to identity the fault when equipments break down.Through software development,functions such as system state conversion,charge and discharge control,high-voltage interlock,insulation detection,and data acquisition were realized.A patented design of "slave and hard-wired combination automatic ID encoding" was applied to effectively solve the problem of the slave encoding of the distributed management system.With regard to battery safety management,faults were systematically defined from the perspective of vehicle demand,combined with vehicle driving conditions.New condition control and fault handling strategies were proposed and implemented in the system.Finally,the developed battery management system was tested jointly,and the system's function,performance verification and fault processing strategy defined from whole vehicle perspective were completed.The results show that the system function and performance can meet the project design requirements.Based on the requirements of a "fuel cell car vehicle industrialization project",this article completes the development of the battery management system,considering its actual application in vehicle.The research work has engineering practical value,as well as reference significance for similar exploitation process of new energy automobile BMS.