Analysis and improvements of novel voltage balancer for an Electric Double Layer Capacitor employing a CW circuit

EDLCs (Electric Double Layer Capacitors) offer high energy density and long life span, so various applications may be anticipated in the realm of energy storage devices, such as those used in electric vehicles or electric power stabilisation in power systems, etc. However, since the voltage limit is low of the devices, it is necessary to connect them in series or parallel. In addition, it is required that they be used in the region of their critical voltage limit or capacity limit. In order to apply them efficiently, the devices should be use with balanced voltage. Firstly, the authors discuss a conventional method, for example using a forward converter, etc. In a second approach, a novel voltage balancer is presented, employing a CW(Cockcroft-Walton) circuit. Characteristics of proposed circuit are analized and discussed.