Residual Energy Estimation of Battery Packs for Energy Storage Based on Working Condition Prediction and the Representative Cell

Residual energy is a direct description of the energy supply capacity of batteries and its accurate estimation is a key issue in current research. However, the residual energy of batteries is significantly influenced by the future operating conditions, and for an energy storage system consisting of several cells, the inconsistency of the cells will lead to differences in the residual energy among them, and it is difficult to estimate the residual energy of all cells with limited hardware resources. Therefore, this paper proposes a method for estimating the residual energy of battery packs in energy storage based on the prediction of operating conditions and the representative cell. Firstly, the definition of residual energy and its influencing factors are analyzed; secondly, the residual energy of batteries is estimated based on the prediction of future operating conditions using Markov chains; finally, a simulation model of battery packs is established to take into account the inconsistency, and the residual energy of battery packs is accurately estimated based on the representative cell with a relative error of less than 0.6%, which is of some guidance for the residual energy assessment of energy storage battery packs in practical applications.