Design and Performance of a 200 kHz All-SiC JFET Current Source Converter

Abstract

Silicon carbide (SiC) switching devices have been widely discussed in power electronics due to their desirable properties and are believed to set new standards in efficiency, switching behavior, and power density for state-of-the-art converter systems. In this paper the design, construction, and performance of a 3 kVA All-SiC Current Source Converter (CSC) also known as Current DC-Link Back-to-Back Converter (CLBBC), is presented. CSC topologies have been successfully used for many years for high power applications. However, for low power range converter systems they could not compete with Voltage Source Converter (VSC) topologies with capacitors in the DC-link, since the link inductor has always been a physically large and heavy component due to the comparatively low switching frequencies of conventional high blocking voltage silicon devices. New SiC switches such as the JFET, which are providing simultaneously high voltage blocking, low switching losses, and low on-state resistance, offer new possibilities and allow for implementing a high switching frequency CLBBC and thus reducing size and weight of the DC-link inductor. The prototype CLBBC has been designed specifically for latest generation 1200 V, 6 A SiC JFETs for a target switching frequency of 200 kHz.