A Variable Capacitance Based Modelling and Parameter Determination for Supercapacitor with Experimental Validation

Recent advancements in technology have made supercapacitors an excellent choice for high power density applications. Accurate modeling is crucial for the effective management and use of supercapacitors, particularly in estimating their remaining useful life such as state of charge (SoC). To closely replicate the dynamics of supercapacitors, a new equivalent circuit model that incorporates factors such as rest period dynamics and capacitance variation, is developed. The forgetting factor recursive least squares (FFRLS) algorithm is implemented for identifying the parameters of supercapacitor. From the experimental data, the model parameters were identified for various operations such as charging, discharging and rest period. Moreover, using this developed model, model validation was done by comparing the measured terminal voltage with that of the model computed one. From the results, it could be inferred that the proposed model accurately captures the supercapacitor dynamics, enabling advanced estimation techniques to generate highly accurate estimates regarding the remaining useful life of supercapacitors.