Performance Comparison of Nonlinear State Estimators for State-of-Charge Estimation of Supercapacitor

Accurate state-of-Charge (SOC) estimation of supercapacitor is very crucial for real-time energy management and control of the energy storage device. This paper deals with performance comparison and analysis of the two most commonly used SOC estimators, namely Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) for remaining charge monitoring of supercapacitors. For that purpose, a completely observable equivalent circuit model of supercapacitor has been adopted in order to design the estimation algorithms. In order to perform the comparative analysis, a commercially available Maxwell supercapacitor has been chosen to conduct experimental studies. Finally, The performance of the estimators has been illustrated via both the single-run and the Monte Carlo runs.