Equivalent Circuit Models for the Analysis of a Commercial Ultracapacitor Module

The paper presents the comparison and the experimental validation of three ultracapacitor (UC) circuit models of the Maxwell Boostcap® module. The more advanced layout takes into account the nonlinear dependence on the terminal voltage, the internal losses and the charge redistribution effects by suitable RC branches. By means of different types of charge tests, the more convenient circuit layout and the related parameter values are assessed to obtain satisfactory agreement with measurements and limited computational time. As an example of application, the model is then adopted for the analysis of an electric vehicle supply system. The operation on a driving cycle based on standard requirements is simulated, evidencing the benefits obtained from the integrated battery-UC supply.