Frequency Domain Analysis for Electrochemical Supercapacitors

摘要

The paper deals with the problem of creating a non-linear model of the electrochemical supercapacitors and measuring their electrical parameters in wide frequency range. Formalization of the model as a non-linear equivalent circuit enables to explain non-linear behaviour of electrochemical supercapacitors such as dependence of their capacity and electrical series resistance (ESR) on the different voltage levels and frequencies. In order to determine the non-linear supercapacitor equivalent circuit parameters we carry out the impedance measurements and then perform fitting of obtained measurement results by means of impedance function, which describes the electrochemical supercapacitor non-linear properties with greater accuracy.