State-of-function evaluation for lithium-ion power battery pack based on fuzzy logic control algorithm

State-of-function (SOF) evaluation is crucial to the effective operation of an electric vehicle (EV) power battery system. The objective of the SOF evaluation is to integrate multiple factors that affect battery performance and evaluate them comprehensively. However, the vital issue in such an evaluation is the apt choice of state parameters that affect the performance of the battery and the establishment of a reasonable relationship among them. This paper proposes a specific and operational definition of SOF on the basis of prior research. The SOF evaluation method is built based on the Fuzzy Logic Control Algorithm (FLCA) and amended according to the requirements of the application. A battery testing system, Lithium-ion Power Battery Pack (LPBP) and EV are used in conjunction with MATLAB for the simulation and experimentation. The experimental and simulated results indicate that the FLCA performs well in evaluating the LPBP SOF. Some typical situations are selected for SOF evaluation to analyze the results and elaborate their significance. The theoretical and practical applicability of the work is highlighted through practical recommendations for LPBPs in EV applications.