Online parameter estimation/tracking for Lithium-ion battery RC model

as a basis for Battery SOC estimation and grid integration numerical analysis, Equivalent Circuit Model (ECM) based on RC circuit topology is one of the most widely-used battery models. In the ECM model, model parameters such as internal resistance, RC circuit capacitance, and resistance are physically time-variant and depend on the battery SOC and temperature. However, as a trade-off on the gap between model complexities computation simplification, the ECM model parameters are usually considered as constant or be piece-wisely constant. In this paper, we proposed an Adaptive Thau Observer(ATO) based online parameter estimation/tracking method, which can estimate the time-variant ECM model parameter such as RC circuit capacitance in real-time. The metrics of this method only depends on measurements of battery voltage and current, which is more feasible for real-world battery SOC/SOH estimation applications comparing with existing offline battery parameter identification methods. Finally, simulation results demonstrate the effectiveness of the proposed method.