A study of SOC estimation algorithm for energy storage Lithium battery pack based on information fusion technology

According to the practical engineering problems of battery energy storage system (BESS), the precision and robust of state of charge(SOC) estimation is becoming increasingly important. The battery pack capacity, operation condition, cycle times, environment temperature, charge and discharge rate has an important relationship, this will affect the accurate of SOC estimation. An SOC estimation algorithm based on information fusion framework and a multi-pattern switch strategy based on the information fusion technology are proposed for Lithium-ion battery. The different operation areas are created on the OCV-SOC curve, i.e. flat voltage area, identification-correction area and over charge/discharge area. In order to utilizing the estimation model according to the different operation areas, the algorithm switches to the optimized estimation model to acquire better performance. Then eliminates the model error which introduced by working state. Finally, by utilizing the actual operation data, experiments and numerical table were conducted, show that this SOC estimation algorithm based on information fusion technology has better robust performance of the practical application of lithium battery energy storage system.