The Research And Realization On Battery SOC Technology

Accumulator management system is an important part of direct current management. By the system, the real-time monitoring for voltage, temperature, charging and discharging current and charge of accumulator is achieved. Accumulator's life length is improved. And the whole system's stability for running is also advanced.In this article, the situation of domestic and abroad about battery managing system(BMS) is presented, and in terms of accumulator physical and chemical features ,the factors affecting accumulator charge real-time monitoring and a series of past accumulator models, empirical model and equivalent circuit model, are analyzed. And the battery SOC model and its character are studied. By combining the character of inner resistance and terminal voltage model, a new accumulator mathematical model, inner resistance- terminal voltage methods, is presented. And the method of various arguments'solving is advanced. The problem of capacity return caused by accumulator temperature's change and motor parking is considered. The mathematical model is designed using latest MATLAB/simulink which is regarded as a base of analysis and research for accumulator battery capacity. The model's reliability and feasibility is confirmed by experiment and emulation result.According to analyzing and emulation, a run-time supervision system of battery SOC based on LIN bus is designed, and the hardware and software are carried out. The hardware system has two parts: one is about related data measuring of single battery, including terminal voltage, temperature and gauged SOC; another is the measuring of the batteries as a whole, including the current, terminal voltage and temperature. The main controller uses C8051 series MCU to realize the supervision of the whole system, and LIN bus to achieve the management of single battery, which not only supervise the running of single battery, but save the cost. The software part contains the initialization of the system, the designation of the A/D and temperature collecting , and the realization of the SOC Algorithm.