A Cell Level Model for Battery Simulation

An equivalent circuit model is the most common and straight-forward way of representing the dynamic behaviour of a lithium-ion battery. In literature, many examples of circuits are proposed and various techniques are also discussed for parameterisation of the models. In this paper a second order equivalent circuit is proposed and the parameters identification method by Hybrid Power Pulse Characterization (HPPC) testing is described. The modelling and parameter identification process is done in the Matlab/Simscape environment. This non-linear model encapsulates the dynamic electrical behaviour of a typical automotive cell. A validation process is carried out to benchmark the voltage errors between estimated voltage profile of the battery cell model and actual cell measurements. The comparison between measurement and simulation shows a good accordance. The current pulse technique is also presented to verify the ohmic resistance values obtained by the optimisation process in the parameters identification method. A study is also conducted to investigate how cell chemistry affects the proposed model.