SOC Estimation Of Power Battery For Electric Vehicle Based On UKF Algorithm

With the development of society, the problems of energy crisis and environmental pollution have become more serious, the research and development of electric vehicle is attracted more and more attention. As an extremely important part of hybrid car, the main function of battery power management system is to make a reasonable estimate of the battery state of charge SOC. The battery SOC accurately determined, it had important significance for longer distance travel and hybrid car battery increases management. In this paper, lithium manganese oxide was used as the main object of study, the lithium-ion battery SOC estimation method was highlighted, The specific steps were as follows:First the development of hybrid vehicles and battery development outlines the background was introduced, and the battery energy management systems in electric vehicles was explained to occupy a very important position, and then the working principle of lithium manganese oxide was analyzed, manganese oxide for lithium-voltage characteristics impact resistance characteristics, efficiency and cycle characteristics of the battery were given a detailed explanation, After SOC definition was amended and introduced several important factors that can affect the battery SOC, and several circuit model was analyzed, the temperature charge and discharge rate, cycle life and self-discharge and other factors were taken into account, while lithium manganese oxide equivalent circuit model PNGV model was established, and finally by HPPC circulation experiments in MATLAB simulation model, the accuracy of the model was to be sure.In this paper, the use of a colorless SOC estimation Kalman filter UKF algorithm based on the standard Kalman filtering method was based on improvements in the prediction phase, UT and UKF algorithm to study the transformation lithium manganese battery SOC estimation algorithm. And a specific gravity between adaptively adjust sigma point scale factor was proposed, the smallest deviation proportional sampling was used, thereby the accuracy of UKF had been improved.Based on the battery equivalent circuit model, simulated in MATLAB, the results showed that UKF estimation error was less than 6%,which had a higher value。...