Research And Design On Battery Management System Of Electric Vehicle

With the fast development of the electric vehicle, the requirement to the battery technology is higher and higher. So the management of the battery working state is also more and more important. The paper has deeply studied the traction battery management system of fuel cell electrical vehicle, and the logical design thoughts and realized methods have been put forward.First the characteristic of the NI-MH batteries and the factors influenced on the state-of-charge(SOC)have been analyzed, and different kinds of SOC measuring methods have been compared. Then a logical SOC measuring method has been raised, which is the combination of open circuit voltage and Ah integration.Then the hardware platform of a distributing battery management has been brought forward. The battery management system has been divided into two parts: one part is designed to measure the voltage and temperature of the every battery based on PIC singlechip;the other part is designed based on DSP TMS320LF2407 to measure the current and total voltage of the battery package, estimate the SOC , alarm and communicate etc. The two parts are communicated via CAN bus to form a distributing system. The whole hardware system is fixed simply to examine and repair.Finally according to the hardware design of the battery management, the sofeware design is also divided into two parts: One part is the software design of the voltage and temperature of every battery, emphsised on the sofeware design of the temperature measurement;the other part is software design based on real time operating system μC/OS-II. The process that μC/OS-II is successfully transplanted to TMS320LF2407 is expatiated in detail, at the same time the design of each user task is realized according to the functions that battery package management system has accomplished. The application of the operating system μC/OS-II not only improves real time, reliability and stability of the system ,but also enhances anti-jamming of the system and improves the accuracy of estimating SOC.The study of the task has made great progress in theory and practice, and has important significance to deeply study battery management system.