Model identification of lithium-ion batteries in the portable power system

Abstract

Portable Power System (PPS) supplies energy for electronic devices outdoors. The lithium-ion batteries are adopted as a kind of ideal energy storage unit for the PPS. In order to monitor batteries, parameter identification should be performed on batteries. To achieve the tradeoff between the accuracy and simplicity, the first order RC model is used as the fundamental model for lithium-ion batteries. Under the working condition, an online parameter identification method, which is combined with the recursive least square (RLS), is proposed in a batch-type working manner. Although the RLS-based identification method can only be applicable to time-invariant systems, the combination of the RLS method and the proposed batch-type working manner can work well to identify the model parameters during the operation of PPS.