On power losses in switched supercapacitor circuits

Based on the Westerlund-Ekstam model, the paper presents an estimation of power losses in an elementary switched supercapacitor circuit. The power losses are found analytically and represented in the form of equivalent resistance. It is shown that as compared to an ideal capacitor, the use of supercapacitor is preferred at low switching frequency, f <;1/(5RC). In addition, a straightforward method to obtain the parameters of the lumped element model of supercapacitor is proposed. The theoretical results were verified by simulations. Possible applications of the obtained results include characterization of the supercapacitors in the time-domain and equalizing the voltages across serially connected supercapacitors.