Series Connection of Supercapacitors: Comparative Study of Solutions for the Active equalization of the Voltages

Because of their low voltage level, supercapacitors need arrangement with series connection in order to obtain voltage levels from few dozen to few hundred of volts. As for batteries, devices have then to be defined to balance the voltages across each series connected components. This paper presents the problematic of voltage sharing in a series connection of supercapacitors. It is generally described the way the balancing of the voltages can be obtained, with the main design rule. It is also introduced how the voltage balancing can be obtained easier with a coherent arrangement of the supercapacitors in their tank. Then, the main solutions for sharing the voltages with active devices are presented, detailed and compared, using a global modeling approach.