Three-phase 4.16 kV medium voltage grid tied AC-DC converter based on 15 kV/40 a SiC IGBTs

Recently, with the emergence of Wide Bandgap semiconductor devices having higher blocking voltage capabilities and higher switching speed, ac-dc converters for Medium Voltage (MV) and Low Voltage (LV) dc micro-grid applications are becoming popular. In this paper, the first time experimental demonstration of such a 3-phase, isolated ac-dc power converter based on the newly developed 15 kV/40 A SiC IGBT is presented for 4.16 kV ac distribution grid interface. The presented converter consists of two bidirectional stages — the 4.16 kV ac to 8 kV dc front end converter followed by an 8 kV dc to 480 V dc dual active bridge converter with high frequency isolation. These stages are switched at 5 kHz and 10 kHz respectively. The converter design is presented along with experimental validation on a prototype at 9.6 kW.