A battery state of charge estimation method using sliding mode observer

In this paper, a simplified battery model and a closed-loop estimation method of the state of charge (SOC) are proposed. The simplified battery model consists only of two resistors and two capacitors, based on which a sliding mode observer is designed to compensate modeling errors when the SOC is estimated. The proposed method can overcome the drawbacks of the conventional SOC estimation methods, such as large cumulative errors. And it is simple and robust to modeling errors. The effectiveness of the proposed method is verified experimentally on a test bench and a power transmission line inspection robot. The experimental results show that the proposed method is effective and can estimate battery SOC.