Chapter 2 - Electrical equivalent circuit modeling

Abstract

The management system is a link between the user and the battery. It can monitor the abnormal situation of the battery. To manage the battery, it is necessary to construct the equivalent model and determine its parameters. In this chapter, various equivalent circuit modeling methods are introduced. The performance analysis of lithium-ion batteries needs the help of experimental equipment. The related work for typical test equipment is introduced, which is of great significance to establish a reasonable and effective battery equivalent model. Especially, the determination of the relevant parameters in the equivalent circuit model plays a key role in the accurate state estimation. As for the modeling overview, some knowledge is described, including types, concepts, equivalent circuit modeling, and commercial circuit models. The Rint modeling and its improvement are conducted, in which the model establishment is conducted together with its internal resistance description by considering the open-circuit voltage characteristic and parameter identification. The analysis of Thevenin modeling provides a scientific basis for second-order circuit modeling. The internal resistance description is conducted for the splice equivalent modeling together with the forgetting factor calculation. The least-square principle is analyzed, according to which the hybrid pulse-power characterization test is conducted for the parameter identification to realize the model accuracy verification.