Research Of Electric Vehicle Battery Management System

With the continuous development of the automotive industry, the traditional internal combustion engine car increase rapidly which bring greater challenge to environmental protection, meanwhile the energy shortage problem is increasingly serious. So in recent years, people have been working on the use of cleaner and more readily available alternative to traditional fuel energy to power a car. As a typical new locomotive, new energy vehicles are high attention by automotive manufacturers. New energy vehicles, mainly and pure electric vehicles, energy carrier most use lithium ion batteries.In order to ensure the safety use of lithium-ion batteries, corresponding management system for effective management must be used at using process.The present situation of the development of electric vehicles, and the function of electric vehicle management system were described and explained in this article, through the analysis of the existing design of battery management system, define the functions of battery management system, research for a60AH battery capacity for a pure electric car. The battery management system uses the basic structure of the control board+cell board, centralized-decentralized network topology, modular design thought, with good stability, strong anti-interference ability. ARM chips (STM32F103RBT6), combined with Linear Technology’s latest integrated battery management chip LTC6803-3, current and temperature sensors built a hardware circuit, drawing the printed circuit board, through software programming, realize the acquisition of overall system battery voltage, cell voltage, current and temperature. Achieve to estimates balanced battery pack and battery state of charge (SOC).Several commonly used SOC estimation methods are analyzed and compared in this article; we propose a new estimation method, which improved of AH. This method combines the AH and the open circuit voltage, using open circuit voltage can timely correct initial charge of the AH and separately compensate to the factor of AH (discharge rate coefficient, temperature coefficient, the system aging factor).Finally functional test for this battery management system, through the analysis of the data comparison and online simulation of SOC algorithm, verify the practicability and superiority of this battery management system.