Switching Loss Characterization of Wide Band-Gap Devices by an Indirect Identification Methodology

The Double Pulse Test is commonly used to measure switching losses of power electronic devices. This method suffers from fast transients, design changes for the current measurement and unclear integration limits. Furthermore, the measured switching losses are invalid for soft-switching operation modes. In this paper, an indirect method is presented, which identifies the switching losses from the total losses of a two quadrant converter operated at various operation points. The proposed method fixes the issues of the Double Pulse Test mentioned above. The method was employed to compare the switching performance of a SiC-MOSFET with new GaN-device in the 900V-class. The comparison revealed that the GaN component performs slightly better for soft switching, while the SiC device is the better choice for hard-switching.