Assessing the Impact of SiC MOSFETs on Converter Interfaces for Distributed Energy Resources

Abstract

Distributed energy resources (DER) will become in the near future an integral component of an electric power distribution system. In most cases, an isolated dc-dc converter is required to connect the DER output to the distribution system. Operation of the converter at high switching frequencies brings size reduction of passive components at the expense of increased switching losses. On the loss issue, silicon carbide (SiC) power devices have a very promising future because of their lower switching losses and ability to work at high temperatures. SiC diodes have displayed the ability to offer more ideal diode behavior than silicon diodes. SiC MOSFETs also have lower switching losses and conduction losses over Si MOSFETs. This display has made SiC devices attractive for dc-dc converters used to connect DER to the distribution system. In particular, this paper deals with the design of a 300 W 100 kHz dc-dc full bridge converter using zero-voltage zero-current switching (ZVZCS) for comparison of SiC MOSFETs and diodes against Si MOSFETs and diodes.