Repetitive Dynamic Voltage Clamp for SiC MOSFETs in Half Bridge Converters

Abstract:
The aim of this paper is to present an investigation on drain-source voltage clamp limit of SiC MOSFETs devices working on a half-bridge converter under repetitive conditions. Voltage clamp phenomenon can take place in power converters when the devices are turning-off; if drain-source voltage oscillations are significant, the real voltage breakdown limit value can be dynamically reached. During this abnormal turn-off event, the device will commutate the load current dissipating more energy. The target of this paper is to submit SiC MOSFETs under this stressful working condition in a repetitive way on several devices and at different driving conditions, by checking after each stress cycle if any kind of degradation could occur and eventually their impact on the reliability of the converter.