Research Of Battery Management System Of Pure Electric Vehicle

With the social development , increasingly prominent energy issues and environmental protection issues, pure electric vehicles with zero emissions, low noise advantages are getting growing attention by the world, known as the green car. Battery management system (BMS), as one of the key technologies for developing electric vehicles, is the key of electric vehicles industrialization.Battery management system direct detects and manages the process of electric vehicles' battery operation, including charge and discharge process, the battery temperature, consumption estimates, the balance between monomer batteries, and battery failure diagnosis.This thesis is devoted to the study of pure electric vehicles' storage battery management system, has discussed design concepts and methods of the system, has brought forward the way to estimate nickel-hydrogen batteries' remaining capacity.The author has analyzed the basic principles of nickel-hydrogen storage batteries the characteristics of charge and discharge, and the main factors of influencing the storage batteries' state of charge (SOC). The nickel-hydrogen storage battery is thought as the the comparatively ideal power source for electric vehicles when the performance indexes, advantages and disadvantages of the current various power storage batteries are compared from many aspects.Have studied the experiences of nickel hydrogen storage batteries' state of charge and the forecasting method that combines integral and calculating, introduced the hardware platform of storage battery group controller based on 485 bus line, using ATMEGA8L as a micro-controller, completing data sampling, 485 module communications, signal conditioning, liquid crystal display and related separation circuit design. Have realized the collection of battery voltage, temperature and electric current parameter, have finished systematic software design.The battery management system introduced by this paper has already got actual application in export electric vehicle. The hardware circuit is reliable and economical. The ability of interference rejection is strong. The estimate of SOC and other related detection data compared with the actual measurement are quite exact.