SiC MOSFET zero-voltage-switching SVM controlled three-phase grid inverter

Abstract

Although SiC-MOSFET has shown significant advantages on switching performance compared with traditional Si counterpart, the dynamic loss of the hard switching SiC-MOSFET converter rises quickly with the increasing of the switching frequency. To further pushing the power density of SiC-MOSFET gird inverter, soft switching inverter with Zero-Voltage-Switching (ZVS) SVM technique is investigated. In this paper the loss distributions and conversion efficiencies of both a 30kW hard switching inverter and a 30kW ZVS inverter with SiC MOSFET devices have been derived and compared with respect to physical size of the passive components with different switching frequencies from tens of kHz to hundreds of kHz. In order to evaluate the efficiency performance of different topologies with the increasing switching frequency, a new concept called Efficiency Endurance is proposed. Both the theoretical and experimental results have confirmed that the ZVS inverter is more advantageous in high switching frequency applications.