Improved battery modeling approach considering operating scenarios for HEV/EV applications

Abstract

This paper presents an improved battery modeling approach based on typical operating scenarios in hybrid electric vehicles (HEVs) and pure electric vehicles (EVs). Compared with the conventional modeling methods, the proposed method takes both the constant-current (CC) charging and dynamic driving scenarios into account, and two separate sets of parameters are estimated through different periods of the pulse-rest test. For the CC charging scenario, data from the pulse-charging period are employed in parameter estimation. For the dynamic driving scenario, data from the rest period are employed, and the length of the fitted dataset is determined by the spectrum analysis of the load current. In addition, the initial voltage expressions of the RC networks in the fitting function are improved to ensure a higher model fidelity. The feasibility of the developed modeling approach is experimentally verified on a 40 Ah LiNMC battery. Experimental results validate the advantages of the proposed approach.