Modeling and identification of electric double-layer supercapacitors

Supercapacitors are emerging new devices for many applications, either as main energy sources or as energy buffers, due to their high power density. To study possible applications of supercapacitors, a terminal model describing the dynamic behavior of supercapacitors is required. In this paper, a simple electrical equivalent circuit model (ECM) is proposed based on the conventional supercapacitor RC branches model. Moreover, a nonlinear optimization algorithm is presented to identify the model parameters. The proposed modeling and identification method was validated with supercapacitor experimental results. The proposed method can be used to simulate and predict the dynamic performance of a super capacitor, assess its energy storage capability. It can also be used in the design of energy management system of many supercapacitor applications, such as, capacitive deionization (CDI), hybrid/electric vehicles.