Self-discharge modeling of supercapacitors using an optimal time-domain based approach

This paper deals with the dynamic simulation of a developed equivalent circuit model of supercapacitors, taking into account the self-discharge phenomenon. The self-discharge is modeled with a time-varying resistance in the equivalent circuit. Using the acquired experimental data of the self-discharge experiments, an optimal number of exponential functions are fitted on the data employing the weighted least-square technique. The optimal number of the functions is determined considering a trade-off between the accuracy and complexity of the model. The results confirm a desirable performance of the model compared with the other similar models. •Variable leakage resistances are considered to model self-discharge in supercapacitors.•Optimal number of exponential functions are utilized to model self-discharge.•The exponential functions are achieved by weighted least-square technique.•The developed model generates a reasonable trade-off between accuracy and simplicity.•Summation of main and delayed branch capacitors results in more accurate VLR model.