Design And Implementation Of Vehicle Power Battery Management System

With the rapid development of the world automobile industry, the global situation of energy and environment are changing more and more severe, the countries in the world are accelerating the strategy transformation of transport energy in order to keep the automotive industry sustainable development. New energy vehicles become an important direction in the future of automotive development. Battery as main power source or auxiliary power source of new energy vehicles is one of key technologies restricting the development of new energy vehicles. This dissertation is about researching and developing of the new energy vehicle power battery management system (BMS).The system employs architecture of distributed network control, including a battery management central module and several sub modules. The central management module selects the PIC18F4685 as controller chip, mainly completes receiving the battery operating parameters from each battery management sub module, the detection of total voltage and current, the calculation of remaining capacity, the diagnosis of battery failure and communicating with the host computer; The sub module selects the PIC18F2480 as controller chip, mainly completes the voltage and temperature detection of single battery, and sending these parameters to the central management module. The communication between central management module and the sub modules is based on CAN bus.In addition, the estimation of battery state of charge (SOC) is an important part of battery management system, in the dissertation, through studying many kinds of SOC estimation algorithms, open circuit voltage method and Ah counting method are employed in hybrid mode, this method is simple and practical. Experimental results show that this method can satisfy the basic requirement of the battery management system (BMS).In order to facilitate the user to monitor the working status of the battery packs in the real-time, a host computer monitoring system is developed based on Labview. When BMS is in operating, the central management module can send the data to the host computer regularly, and then users can observe the parameters of the battery packs in the real-time, and these parameters can be analyzed, processed, saved and so on.Finally, through testing to the battery management system, the results show that the system can collect the data accurately, reliably and in real-time, meet the basic demand of estimating the battery state of charge, and the system network communication operates normally.