Research And Development Of Simulation Test System For Battery Management System

Battery management system(BMS)is one of the key components of the electric vehicle.In recent years,it is expected that the output of new energy vehicles will reach 2 million with the rapid expansion of the new energy car market in China by 2020.Therefore,the demand for BMS is increasing rapidly with the explosive growth trend of the electric vehicle power battery market.In order to ensure the safe and reliable operation of BMS on electric vehicles,it is strictly important that make strict test and inspection according to the relevant regulations before the products are released.In order to improve the safety and reliability of BMS in practical application,we need to establish a set of testing system that can test BMS function and performance reliably.In this paper,the distributed BMS is taken as the research object.On the basis of fully analyzing the hardware features,software functions and control strategies of BMS,the overall design scheme of the BMS simulation test system is proposed.Meanwhile,the development and implementation of the simulation test system are guided according to the overall scheme.Firstly,we complete the collection of battery charge-discharge data through lithium battery experimental equipment.The identification of the first order equivalent circuit model parameters is realized by the least square method,and the charge-discharge characteristics of the battery are analyzed.The SOC estimation of lithium battery is completed based on the extended calman filtering algorithm.Secondly,the development of the hardware and software parts of the dSPACE system is realized by combining theory analysis with practice application.The verification of battery model and SOC accuracy in dSPACE system is completed.A comprehensive induction and analysis of BMS internal network and charging CAN communication protocol is presented.The simulation of CANoe part based on J1939 protocol is implemented,including charger,local electronic central control unit,etc.The construction of simulation testing system based on dSPACE/CANoe is completed.Thirdly,the collaborative communication test based on dSPACE/CANoe system is completed.The overall performance of the simulation testing system is also analyzed.And the feasibility and correctness of the system are verified.Through the joint simulation of dSPACE/CANoe system,the battery model accuracy test of BMS is completed.The experimental results show that the SOC accuracy of BMS can meet the engineering requirements.For BMS control strategy test,the thermal management control,equalization control,high voltage up and down power control and other test cases are used to verify.The results show that BMS can process fault states in a timely manner,which is in line with the actual use requirements.