Research on SOC hybrid estimation algorithm of power battery based on EKF

Accurate estimation of power battery SOC(state of charge) is the basis of HEV power control strategy. SOC estimation algorithm has a significant impact on the accuracy of SOC estimation. This paper described the basic concept of SOC, discussed the significance of SOC estimation algorithm, difficulties and the main factors affecting SOC estimation, proposed a hybrid battery SOC estimation method with combination of extended Kalman filtering algorithm and improved Ampere Hour(AH) Method based on analyzing existed algorithms. Experimental results show that the hybrid SOC estimation method can meet the accuracy requirement of HEV SOC estimation excellently and is superior to the individual EKF method.