Sumida Builds 100 kVA Transformer With Infineon
The medium-frequency transformer targets solid-state transformer designs for AI data centers, EV charging, and grid systems.
Updated on Nov. 3, 2026 in Semiconductors
Sumida has built a 100 kVA medium-frequency transformer for solid-state transformer designs, developed with Infineon. Infineon supplies the 3.3 kV CoolSiC switching devices on either side of the transformer.
Why it matters
Raising the magnetics to tens of kilohertz reduces the size and weight of a solid-state transformer. Target applications include AI data centers, EV fast charging, battery storage, renewables, microgrids, and rail, aircraft, and marine systems.
The 100 kVA unit operates at a 40 kHz resonant frequency, passes an insulation test above 20 kV, and holds a partial discharge extinction voltage above 14 kV, with leakage inductance of about 150 μH. Efficiency, losses, cooling method, volume, and weight were not disclosed.
The players
Sumida
Sumida is a Japanese electronics manufacturer known for magnetic components, including transformers and inductors.
Infineon Technologies
Infineon Technologies is a German semiconductor company and a major supplier of power semiconductors, including silicon carbide devices.
The details
Sumida handled the magnetic materials, winding, thermal design, and medium-voltage isolation. Infineon supplies the 3.3 kV CoolSiC switching devices for the stages on either side of the transformer.
Timeline
Announcement of the 100 kVA medium-frequency transformer published on November 3, 2026.
The Tech Race
The effort pairs Infineon's 3.3 kV CoolSiC silicon carbide switches with Sumida's magnetics to push solid-state transformers into higher-frequency designs. Sumida calls this the first step toward 35 kV-class isolation, extending the high-voltage reach of wide-bandgap power chips.
Smaller, lighter solid-state transformers could eventually shrink the power conversion gear inside data centers, fast chargers, and battery storage sites. The announcement did not give a timeline for commercial availability or pricing.
The takeaway
Higher-frequency magnetics paired with silicon carbide switches are a key route to smaller solid-state transformers. Readers tracking power electronics for data centers and EV charging should watch for efficiency and commercial figures in later disclosures.
What happens next
Sumida calls this the first step toward 35 kV-class isolation, though no date for that follow-on work was given.
Further reading
For more on the chips powering this design, explore our Semiconductors coverage.
