Technical Papers
Electrochemical Capacitor Voltage Balance: Cell Uniformity
Requirements for High-voltage Devices
John R. Miller
Abstract
This paper presents results from our investigation of cell uniformity requirements for high-voltage electrochemical capacitors (ECs). A lumped element equivalent circuit model is first derived to simulate the electrical response of a single cell. Complex impedance data is used for this. Then a high voltage EC model is created by series connecting these single-cell circuits. Finally, model performance is statistically evaluated using a Monte Carlo analysis. Both static and dynamical performance is reported. Cell voltages are obtained as a function of the specified tolerances for each element in the single-cell equivalent circuit model.
The presented approach establishes the relationship between cell uniformity
specifications and the maximum average cell voltage that a multicell EC
can be operated at reliably. This approach can readily be extended to include
thermal manage ment specifications.
Copies of this paper are available, on request, by fax or mail, from Evans Capacitor Company, 33 Eastern Avenue, East Providence, RI 02914. Phone (401) 434-5600. Fax (401) 434-6908.