APEC 2017 “Robustness of SiC MOSFET under Avalanche Conditions”
This paper presents the experimental evaluation of SiC MOSFETs from different manufacturers operated in avalanche.
This paper presents the experimental evaluation of SiC MOSFETs from different manufacturers operated in avalanche.
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).
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%.
The recent interest in renewable energies has encouraged the research on a new concept of electrical grid - the Supergrid based on HVDC meshed grids. To be implemented, this new system requires the development of new technologies. One key-enabling technology is the high power DC-DC converter, a topic that is increasingly gaining more attention from both academia and industry.
The silicon carbide (SiC) power semiconductor and the medium frequency transformer (MFT) are two enabling technologies that are allowing the efficiencies and power densities of power electronic converters to be pushed beyond the limits of those that have previously been possible...
In the future, Medium Frequency Transformers (MFT with a frequency range 5 kHz to 100 kHz) will be major components in DC-DC converter applications, for both Medium Voltage Direct Current (MVDC) and High Voltage Direct Current (HVDC) networks. Importantly, the corresponding power losses should be accurately calculated in order to reach performance targets (very high efficiency).
SuperGrid Institute has succeeded in the preliminary tests on their first DC-DC power converter in September 2015. The power converter nominal power is 100 kW with an input voltage of 1 kVdc and an output voltage of 500 Vdc. The converter topology is a Dual Active Bridge with silicon carbide transistors and a medium frequency transformer.