SiC Technology in Medium Voltage Applications

SiC Won Low Voltage. Now It Is Moving Up.

Silicon carbide (SiC) MOSFETs have already won the low-voltage battleground — EV traction inverters, solar microinverters, telecom power and server PSUs switched to SiC because faster switching and lower losses paid for themselves in efficiency and size. The next battleground is medium voltage: the 1–35 kV range where the grid, industry and large loads live.

What Changed in Medium Voltage

Medium-voltage power electronics was long dominated by silicon IGBTs, for a simple reason: silicon MOSFETs could not block high voltage with acceptable on-resistance. SiC breaks that trade-off. Commercially available SiC MOSFET modules now cover 1200–3300 V, and the practical consequences ripple through MV converter design:

Where SiC Unlocks MV Applications

Solid-state transformers

SST is the flagship MV SiC application. The high-frequency isolation stage requires fast, low-loss switching — SiC makes the frequency high enough that the transformer shrinks to a fraction of line-frequency iron, and the loss low enough that efficiency stays above 99%.

MV drives and grid equipment

SVG, APF and grid-tied converters gain efficiency and shrink cabinets. Harmonics, filtering and reactive support become cheaper to deliver, which matters as grid codes tighten.

Charging and storage

SiC PCS raises storage round-trip efficiency and makes megawatt charging hubs practical without oversized equipment rooms — the same device technology, applied at the converter level.

The Engineering Realities

SiC is not a drop-in for IGBT designs. Its benefits come with engineering responsibilities:

• Faster edges, tighter layout: high dv/dt demands low-inductance busbars and careful gate-driver design (CMTI, Miller clamping, fast desat protection)
• Thermal concentration: losses concentrate in small dies — real waveform-based loss calculation and liquid cooling for MV classes
• Higher first cost: SiC modules cost more than IGBTs; the payback comes from efficiency, size and system simplification — and must be modeled per project

Related: SiC Power Module Guide · SST Technology Introduction · MV SiC Power Modules