Applied Research Of CAN Communication Technology In The Battery Management System

With the prosess and the development of society,people's life demand become higher and higher.In recent years,many place occurred the kind of sustained fog.The motor vehicle exhaust emission has great role in the sustained emergence of the haze.Therefore,our country is promoting the development of the new energy vehicle technology.The technology of battery management system is the core of the new energy vehicle technology and now the BMS designer mostly focus on distributed control system.In order to realize data transmission of the battery management system between various modules,the separated design and research of the BMS's communication module is necessary.In consideration of the advantage about controller area network can bus(CAN),the CAN bus is used as the communication of BMS.So it is of great significance and great value to research the CAN communication technology.This paper has designed the communication modules on the basis of CAN bus.The main research work includes the following several aspects.(1)BMS that use distributed control system need to decide network topology clearly and communication protocol of all BMS's modules and guarantee the reliability of data transmission between different modules.In order to meet the needs of different functions requirement,the battery management system CAN network can be divided into two major kinds of network communication and separate the internal data and external data,so that can improve the reliability of each CAN network.On the other hand,the data communication between different modules is based on the communication protocol.The CAN bus's transport protocol is the protocol of every CAN network.On the basis of the clear network topology,set up communication protocol and provides the foundation for the realization of the BMS's hardware and software at the theoretical level.(2)Design the hardware and software of BMS's CAN communication part,realize the function of the whole communication module.The hardware is the basis for the realization of the functions.The dasign of the BMS's software mainly include the realization of the J1939 communication protocol,the realization of the application layer protocol about data transmission and the realization of communication protocol between BMS and battery charger(3)To realize the the real time updata of BMS's software when BMS is in testing process,deaign CAN Bootloader.According to CAN Bootloader,the code can be updated from CAN network.Then download the code without the need that take BMS out from the battery pack.