Electrochemical Capacitor Voltage
Balance: Cell Uniformity Requirements for High-voltage Devices
John R. Miller
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