Evaluation and Analysis of Circuit Model for Lithium Batteries

Lithium battery is commonly used in energy storage system because of its long service life and high energy density. In this paper, five common equivalent circuit models of lithium batteries are evaluated and analyzed. By utilizing the hybrid pulse power characteristic (HPPC) method, the parameters identification of each circuit model is achieved through curve fitting and then their simulation models are established in Matlab/Simulink. By comparing the simulation results with testing data, the performance of each circuit model is discussed. The results show that the second-order RC model matches well with test data, while the rest four models have a relatively larger error. It should be noted that the main contribution of this paper is to analyze the performance of different circuit models for lithium battery, the accuracy of each circuit model may vary with each specific lithium battery. The optimum type of lithium battery circuit model shall be selected accordingly.