Modeling and observability study of lithium-ion batteries for automotive applications

摘要

Accurately modeling the dynamic behavior of a lithium-ion battery is one of the major themes for researches on state of charge (SOC) estimation. A large number of experiments were performed at different discharge rates and operating temperatures for three compact lithium-ion batteries aiming at determining the relationship of open circuit voltage (OCV) with SOC. The curve of OCV-SOC is approximated by nonlinear function instead of piecewise linear in order to ensure modeling accuracy. The observability judgment procedure of a lithiumion battery system using Lie derivative is given. The modeling validity and observability of the lithium-ion battery system are verified by experiments.