Journal Article

Variable Recursive Least Square Algorithm for Lithium-ion Battery Equivalent Circuit Model Parameters Identification

El Marghichi, Mouncef, El Hantati, Issam, Loulijat, Azedine

2023

Overview

For SOC (state of charge) assessment techniques based on electrical circuit models, the parameters of the model are strongly biased by: battery aging, temperature, causing some errors in the estimation of the SOC. One approach to solve this problem is to update the model parameters constantly. We suggest a new algorithm VRLS (variable recursive least squares) to update the parameters of a 2-resistor-capacitor (RC) network and to estimate the output battery voltage. VRLS is compared to the recursive least squares (RLS) and the adaptive forgetting factor recursive least squares (AFFRLS) algorithms. For algorithm assessment, we utilized real experimental data conducted on the Samsung 18650-20R lithium-ion cell. The tests indicate that compared to RLS and AFFRLS methods, VRLS recorded a low distribution in the high error range, in addition to small predictive performance indicators (RMSE, MAE, and MAPE) in all tests, which implies that VRLS has a good parameter identification ability.

• Publisher: Periodica Polytechnica, Budapest University of Technology and Economics
• Subject: Accuracy / Algorithms / Computer engineering / Computer science / Electric cells / Electric charge / Electrical engineering / Equivalent circuits / Kalman filters / Least squares / Lithium / Lithium-ion batteries / Mathematical models / Methods / Parameter estimation / Parameter identification / Performance prediction / Rechargeable batteries / Root-mean-square errors / Spectrum analysis / State of charge