Difference-based Identification Method for Systems with Rate-independent Hysteresis and Its Application to Rechargeable Battery

Abstract In this paper, we consider identification of a linear system connected in parallel with the rate-independent hysteresis. Since the parallel system provides only the combined output of the two systems, it is required to extract the signal related to the target system from the observed data to identify the systems separately. In order to achieve this, we propose a system identification method, in which the identification experiment is performed twice with appropriately designed input signals. The inputs make the responses of the hysteresis identical in the two experiments, therefore the difference of the two observed outputs is related to only the target linear system. Then, the linear system is identified using the difference. The proposed method is applied to a rechargeable battery, whose output originates from the nonlinear and the linear elements: open circuit voltage with hysteresis and overpotential. The effectiveness of the proposed method is illustrated through a numerical simulation of the rechargeable battery.