Optimization of hybrid pulse power characterization profile for equivalent circuit model parameter identification of Li-ion battery based on Taguchi method

Abstract

The modeling of Li-ion batteries is crucial for their stable and efficient operation. The equivalent circuit model (ECM) is the most widely used battery model, for which parameter identification usually involves the hybrid pulse power characteristic (HPPC) test. However, since the HPPC test was designed to determine dynamic power capability of batteries, an investigation of how HPPC parameters affect ECM parameter identification would be reasonable. In this study, the Taguchi method was employed to investigate the effect of four HPPC parameters (positive and negative pulse height, length of pulse and length of relaxation) on ECM's performance under various application conditions (dynamic test, non-dynamic test and quasi-static test). The results show that all four parameters have an effect on ECM performance. For batteries operated only with the predictable charge and discharge patterns, the optimal combination of HPPC parameters values was determined based on Taguchi experiments. If batteries face unpredictable application scenarios, lower positive pulse heights, higher negative pulse heights, shorter pulse lengths and longer relaxation lengths within a certain range should be considered. Compared to established standard parameter values, this makes it possible to build a more accurate general model.