Modeling of a supercapacitor with a multibranch circuit

•Multibranch equivalent circuit to model a supercapacitor.•Temporal characterization of the multibranch circuit.•Simulation and validation of the multibranch model.

The modeling of a supercapacitor by an electrical circuit composed of multiple resistors and variable voltage capacitors is studied. The temporal characterization is performed with a realized test bench with accurate data acquisition for the different charge and discharge protocols. Access resistance and RC branches are identified for the different time windows. The experimental characterization is detailed for the transmission line and for the complementary branches which reproduce redistribution and leakage current. Thereafter, the implementation of the equivalent circuit in the Matlab/Simulink environment is shown, namely the consideration of non-linear behaviors of the capacitances regarding voltage. The found characterized values are entered in the model to simulate charge/discharge of the supercapacitor. Agreement between simulated and experimental results proves the consistency of the time constant determination approach.