Design And Research Of Battery Management System Of The Micro-pure Electric Vehicle

China’s automobile production and sales were more than18.5million in2011.With more and more petrol-driven cars on the road, the phenomenon of air quality deterioration and oil resources shortage by automobile emission are more and more serious, the sustainable development strategy practice and environmental protection in our country urgently needs new model cars of low fuel consumption and low emissions to replace fuel machine cars. Pure electric vehicle characterized by zero emissions, zero pollution and no oil resources consumption are increasingly welcomed and praised by more people. Accumulator is the power source of pure electric vehicle, the performance of battery electric vehicle depends on whether the control with Battery is rational and effective. The design and research of Battery Management System (BMS) has becomes a key technology restricting the development of Pure EV. Thus it can be seen that the research of BMS has great theory value and practical significance.Combined with general requirements and design concept of Chang-an Pure EV, this subject selected series connected battery packs which consists of eight Lead-acid battery monomers as the motive power; In this project, we studied the BMS based with the master chip of PIC18F4580singlechip; The system can realize the measurement of the single battery voltage, total voltage, battery thermal, battery charge and discharge, insulation resistance and other things; The BMS would give warning prompt when testing found out that some parameter exceed the regular range, and sent the information to vehicle management system through CAN bus, then the vehicle management system takes improvement actions to malfunctions to accomplish its function.The engineering of BMS is split into hardware and software, both of which using modular design.Hardware design includes voltage monitoring module, temperature measuring module, current measurement module, fault alarm module, insulation resistance detection module, communication module and so on; the system software design includes main system program, voltage monitoring subroutine, temperature detector subroutine, current detection subroutine, initial SOC process subroutine, SOC estimation subroutine, insulation resistance detection subroutine, CAN receiving and sending subroutine and so on. Anti-interference measures are used in hardware design which is a good way to ensure stability and dependability of the BMS as the work proceeds.In the simulation system, it proved the stability and dependability of the BMS on the base of analyzing on data gathered from BMS and Chang-an synthetical test stand and also has proven good real-time and high sample frequency merits of BMS. So the subject has basically complete the function of system design which meeting the safety request and design target.