Study On SOC Estimation By Coupling Capacity Modified Ampere-Hour Method

When using the Ampere-hour integration (Ah) method to estimate the state of charge (SOC) of battery, the mechanism and working conditions of the battery will have different effects on the battery capacity. When the battery aging and working conditions change, the estimation accuracy of Ah method is challenged. In this paper, the capacity optimization coefficients such as battery aging degree, ambient temperature and discharge rate are added to the Ah method, and the coupling capacity modified Ah method is proposed to correct the capacity deviation in real time, so as to improve the real-time estimation accuracy of SOC. Finally, experiments show that the coupling capacity modified Ah method can effectively correct the battery capacity deviation in real time, reduce the cumulative error, and effectively improve the SOC estimation accuracy of the Ah method.