This paper deals with a new model of supercapacitors working with a DC-AC converter. The principle of the proposed test structure is to control the energy exchange between the pack of supercapacitors and the grid. The supercapacitor is directly coupled to the common dc-link of whole bidirectional DC-AC converter. A control strategy of the converter using a phase-locked loop (PLL) to regulate the current of the dc-side is presented. In this paper, the authors have discussed the modeling and parameter identification of the proposed model. Finally, experimental results are presented and compared with a simulation model.