Design On Lead-Acid Battery Management System Of Electric Vehicle

In recent years, due to the increasing exhaustion of oil resources and growing environmental problems, more and more governments and the world's major auto manufacturers pay attention to the development of new energy vehicles. Motor drive system, vehicle control system and power management system are three key technologies to develop electric vehicle. Currently, the widespread problems of electric vehicle battery are short mileage, battery life is low and the maintenance cost. Thus, the power management and protection technology of vehicle battery becomes increasingly important.The paper introduced the main functions and domestic and international development of electric vehicle battery management system, introduced the source of the topic, described the working principle and the main characteristic and remaining power prediction model of lead-acid battery, proposed the design method for estimating the remaining battery charge according to a large number of battery experiment data of charging and discharging. The paper achieved a balanced charge control during the charging process,According to the manufacturer's requirements, this paper of the battery management system should include the following basic features: real-time monitored the voltage of each single cell, the overall current value of battery charging and discharging, the external temperature value; estimated the remaining battery power based on the collected data, determined the current status of the battery; open the battery pack protection circuit when the single battery failure; and should transmit the information of the remaining battery power by communication module to the car dashboard.For the above functional requirements, this paper used microcontroller as the master control chip; combine the distributed collection and centralized control as hardware solutions; described the hardware selection of the MCU, battery parameters, balance and protection circuit, power conversion circuit and external communications; design software by using Keil software development environment; achieve the three main processes software design of battery management system; tested the whole hardware and software by lots of charging and discharging experiments;c verify the feasibility and stability of the hardware and software through experimental data collected.