SuperGrid Institute has achieved a major milestone in the development of 10 kV Silicon Carbide (SiC) devices such as 5A BJT and 50A PIN diode as part of its work on developing innovative solutions for MV converters. Recent tests revealed outstanding switching performances.

The research on SiC has progressed significantly over the last 30 years. From the complete assessment of its material properties to the commercialisation of discrete devices, a considerable effort has been invested in advancing this field of research. This work has proven that the intrinsic properties of SiC can be exploited and are not just a researcher’s fantasy. Today, automotive markets are the ones pushing production and devices ranging between 650 V and 1200 V have gone into mass production. Although cheaper SiC counterparts exist, SiC MOSFET in this range is very appealing because of its superior performance.

When dealing with higher voltages (6.5 kV and above) and applications such as power inverters, High Voltage Direct Current (HVDC) and Medium Voltage Direct Current (MVDC) converters and Modular Multilevel Converter (MMC) submodules, SiC Bipolar Junction Transistor (BJT) exhibit lower conduction losses. In addition, due to the absence of gate oxide, the BJT is more robust and can notably withstand higher temperatures.

Recent characterisation tests assessed the switching performances of these devices and revealed sharp turn-on/turn-off behaviour and low losses, confirming the promising results expected from their use. Furthermore, repetitive short-circuit tests on BJTs in various conditions exhibited remarkably stable characteristics and higher performances than those shown by SiC-MOSFET devices.

These tests were made possible thanks to the unique performances of SuperGrid Institute’s test platforms. SuperGrid Institute has invested in no more than 4 HV Power Electronics test platforms that cover a wide spectrum of characterisation services, including the HVSW test bench which is able to perform switching, short-circuit and avalanche tests up to 20 kV/100 A.

The aforementioned results have been accepted for publication in several well-known scientific journals in addition to the participation at ICSCRM 2019. Further publications will be submitted during EPE2020 in Lyon.