Research And Implementation Of The Lithium Ion Battery Management System

As power and energy, Li-ion battery is widely used in cell phones, laptop computers, UPS (Uninterruptible Power System) and electric vehicles. but the overheating, overcharge, over-current and squeezing conditions will lead to short the battery life, and even occur security issues such as fire, explosion, the Li-ion battery system management system has become the key equipment to solve this problem. Li-ion battery management system has a great significance to improve battery life and ensure the safety of the battery.This thesis mainly introduces the Li-ion battery management system. Firstly this thesis analysis Li-ion battery management system functions, and proposes solutions for abnormal diagnosis and protection, balanced management, the State of Charge (SOC) and communication management. This thesis provides basis for abnormal diagnosis, adopts dissipative equalization scheme to solve the inconsistency of the battery, combines AH method and open-voltage method to meet the system SOC requirements, uses RS232serial commutation to send system information to computer in real-time, adopts crystal oscillator switching, due to lower ADC sampling and the rational allocation of port to reduce the power consumption of the system.Then from the point of hardware and software, this thesis gives the detail description. According to the overall design and modular design ideas, this thesis gives the detail hardware description on data acquisition unit, system display, protection and charge or discharge control, equalization management and communication function. Using the structured design and modular design concept, this thesis gives the detail soft description on data acquisition module, abnormal handling and system display module, short-circuit and control module, equalization management module and the lower communication module. At the same time this thesis is also design an upper computer system which is able to display the battery information, warning and system threshold and gives the detailed description on the process of the upper computer. According to experiments, the system is circuit reliable, low cost, strong anti-interference, able to safe and stable operation.