This manuscript is a contribution to reliability and robustness study of MOSFET components on silicon carbide “SiC”, wide band gap semiconductor with better characteristics compared to silicon “Si” material. Those new power switches can provide better switching frequencies or voltage withstanding for example in power converter. SiC MOSFET are the results of approximately 10 years of research and development and can provide increased performances and weight to some converter topology for high voltage direct current networks.

High Voltage Direct Current (HVDC) converters are composed of hundreds of semiconductor switches connected in series to sustain the rated voltage of the converter (several hundred of kilovolts). Because of the large number of switches, it is highly probable that at least one of them will fail during the lifetime of the converter. Such failure should not cause the entire converter to shut down, despite the series connexion of the switches. As a consequence, each switch should be designed so that upon failure, it becomes a short circuit and keeps carrying the current (“fail-to-short” behaviour).

The transmission and distribution of electric power is normally made by ac networks (50 Hz or 60 Hz), where one of the key elements of this infrastructure is the power transformer; used for more than a century, its design is very well understood, with a level of operating efficiency normally greater than 99%.