Supercapacitor Modeling from Cell to Module Level via Robust Single-Test Parameter Identification

Supercapacitors-based power supplies are becoming increasingly common for applications that demand rapid and significant power fluctuations. To effectively evaluate their benefits and limitations during system design and control, equivalent models are essential. However, highly accurate models affect the computational burden during both parameter identification and simulation phases. Given the large number of supercapacitor modules that must be interfaced with power converters in such applications, system design often prioritizes overall functionality over precise modeling of supercapacitor transients. As a result, model accuracy can be partially sacrificed to accelerate simulations and simplify parameter identification. Nevertheless, critical dependencies of SC behavior on operating conditions such as voltage, frequency, and temperature must still be accounted for. In this context, this paper selects a 2nd order model that balances simplicity and representativeness. This model offers a simplified parameter identification process, which only requires a single discharge measurement of the supercapacitor under analysis. While the methodology has previously been validated on individual cells, this paper extends the validation to supercapacitor modules, which operate at higher working voltages and are made of series and parallel connected cells, including their unknown internal active/passive balancing system.