Parameter Estimation of Variable Leakage Resistance Model of Supercapacitor

A fully charged supercapacitor (SC) experiences charge redistribution and self-discharge immediately after the disconnection of the charging circuit. This process depends on many internal and external factors includes the charging current, temperature, manufacturing conditions, etc. An accurate equivalent circuit model is necessary to determine the Self-discharge rate of an SC, which will have a huge requirement in the industry, especially to predict the range of SC-based electric vehicles. Among the various equivalent circuit models available in the literature, the variable leakage resistance (VLR) model proposed in this paper predicts the self-discharge rate of 360F and 480F SCs. A numerical approach with the help of the MATLAB Simulink platform is used here to capture the variable leakage resistance from the charging and self-discharge plot, which was obtained experimentally.