State Estimation of the Battery State of Charge in Reconfigurable Energy Storage Systems Considering Temperature Effects

To estimate the state of charge (abbr. SOC) of the li-ion battery accurately, considering the temperature effect on the basis of the reconfigurable battery module, the temperature-corrected SOC of the reconfigurable battery could be estimated by combining with graph calculation. Firstly,the open circuit voltage (abbr. OCV) and SOC reference relationships of the battery at different temperatures were obtained through experiments, and a thermal model of the reconfigurable battery pack was built to analyze the effect of temperature. Secondly, a reconfigurable battery network graph model was built, the depth-first graph was used to traverse and access battery topology, the optimal connection method after temperature correction was found, and the SOC of the individual battery was estimated using the OCV method. Finally, simulation results demonstrate that temperature correction can reduce the temperature error in reconfigurable battery topology and improve the SOC estimation accuracy of the reconfigurable energy storage system.