Fractional Order Modeling and Parameter Estimation of Supercapacitor

Supercapacitors (SC) have recently gained prominence in energy storage systems due to their distinct porous doublelayer structure which enables its great longevity, higher power density and its prompt response. A precise model for the SC is required for accurate evaluation of its charge/discharge states which determines the energy storage efficiency and power delivering capacity. The conventional electrical equivalent circuit models have been proven to be inefficient in analysis owing to the unique nature of the SCs. The recent development in fractional order calculus has enabled a more accurate representation of its porous nature and diffusion dynamics. In this context, this article considers a more accurate Fractional order model (FOM) model representation of SC and contributes analytical formulation of voltages of the SC for different levels of charge/discharge cycles. The parameters of the proposed model have been estimated using the Genetic Algorithm (GA) approach utilising the experimental and simulated data. The proposed model and formulations are supported with the extensive experimental data from the discharge/charge profile of the Eaton 1F 2.5 V SC.