Design And Implementation Of Battery Management System Based On XS128and DZ60

In recent years, as an effective method to resolve problems such as recource shortage and environment pollution, electic vehicle (EV) is developing rapidly. Battery plays an important role in electric vehicles, but it has the problems such as overcharge, over discharge, over current, temperature and etc, when the batteries are using by group, which is restricting the development of electric vehicles. So it’s necessary to use a battery management system to manage and resolve the problems and ensure the batteries working safely and reliable and extend the batteries’using age. Currently, the research in battery management system is still at the primary stage both at home and abroad. Battery management system is integrated with sensor technology, communications technology, electronic technology, computer technology and embedded technology. So it’s difficult to develop the system. The paper applied16-bit embedded microcontroller MC9S12XS128and8-bit embedded microcontroller of Freescale Company into the system and completed the system in accordance with the battery management system technical requirements of the electric vehicle. This system has high measuring precision, complete functionality, and configuration flexibility, so it can satisfy different application situations and requirements.The paper takes use of the design sampling by group and processing through the bus. The hardware is divided into the controlling board and the unit board, which improves the flexibility of system application. According to the design theory of hardware component, it builds the system hardware platform, and completes the hardware drivers. Following the principle of modular design, it achieves data collecting, power estimating, records storaging, diagnostic alarming, charge control functions and so on. This method reduces the complexity of system design and improves the maintainability of the system. Users can also configure the system parameters through the touching screen or PC to meet the different requirements of different applications, which may need different numbers of batteries. The controlling board communicates with the unit boards through CAN bus, and its communication protocol abides by SAE J1939standards, which makes it easy to interconnect with the charger and the main controlling system and enhances the compatibility of the system. The accuracy of the system parameters is the basis of the system to calculate and control, so it is also an important part of the paper. This paper designed a current collecting circuit, which based on the design of closed-loop controlling hall-effect sensor and extended dual-slope-integrating ADC. This ensures the current sampling precision. Using the design scheme of integrated silicon, the paper applied Linear Company LTC6803to implement the voltage and temperature detecting, and balanced management, which improves the system integration and anti-jamming capability.System testing is also an important part of the system design. The paper proposes a component-based hardware unit testing method and verifies the accuracy and correctness of the system by the precision and functional testing. The design of this system has a reference value for the later design of battery management system.