Bidirectional HV DC-DC converters for energy harvesting with dielectric elastomer generators

Abstract

For the control of Dielectric Elastomer Generators (DEGs) a special high voltage power-electronic (HVPE) is necessary, driving this kind of novel generators at high voltages and typically low currents. In order to supply the generator with initial charges and to harvest the generated energy, the HVPE must also enable a bidirectional energy transfer. Concepts of high voltage DC-DC converters suitable for charging Dielectric Electroactive Polymers can be found in literature, but these often enable only a unidirectional energy transfer. Therefore, this paper discusses two bidirectional DC-DC converter topologies and their suitability as HVPE for energy harvesting. After defining the requirements to the HVPE, a value benefit analysis is introduced along with evaluation criteria and importance factors. After discussing several high voltage DC-DC converters and bidirectional converter concepts, a flyback converter and a Dual Active Bridge (DAB) converter concept are analyzed, evaluated and compared. Based on the defined criteria, it is proposed that the flyback converter topology is more suitable for small power ranges, while DABs cover the larger power ranges.