Research And Implementation Of A Lithium-ion Battery Management System For Electric Vehicle

The dual pressures of oil resources exhaustion and environmental pollution promotes the development of electric vehicles. The battery management system(BMS) is one core technology of electrical vehicles, monitoring the work state of power battery pack in real time, equalizing the non-uniformitys. It’s important for the battery safety and cycle-life.First this paper studies the performance characteristics of lithium-ion battery, in order to improve the state of charge (SOC) estimation accuracy, Studied the ambient temperature, charge and discharge current, the impact of aging and self-discharge cycles and other factors on SOC estimation, designed with improved current integration method to complete SOC estimation. Aiming at the shortcomings of various equalizer studied two-way charging balance control methods. Multi-balanced transformer circuit, a battery pack in bidirectional equilibrium arbitrary monomer.Then, according to the characteristic parameters of battery pack, this dissertation designes the battery management system which is based on CAN bus, including software and hardware design method. In the hardware, Complete distributed system hardware design, circuit designing and testing, and study the hardware anti-jamming measures; In the software, Modular hierarchical design method, a layered software architecture design master module and cell modules studied CAN bus ad hoc network protocol layers to complete the software coding modules and study the software anti-jamming measures.Finally, a series of experiments is done for the battery management system, through the analysis of data, The front parameter acquisition module reaches the system design specification in this design, Equalization module has high efficiency and good reliability.