C. Main design steps
Design of an ultra-capacitor for power conversion
application can be split into four steps.
• The first design step is selection of the ultra-capacitor
module voltage. Voltage rating depends on the application
requirement and topology of the interface converter [5].
• The second design step is selection of the module
capacitance. The module capacitance is selected
according to the application requirements, such as energy
storage capability and conversion efficiency.
• The third design step is calculation of conversion losses
and thermal stress of the ultra-capacitor module.
• Final design step is design of the string voltage balancing
circuit.