ETH Zurich Power Electronic Systems Lab and Professor Johann Kolar

The Power Electronic Systems Laboratory at the Swiss Federal Institute of Technology (ETH) Zurich, led for 23 years by Professor Johann W. Kolar, is the European academic counterpart to NCSU FREEDM and Virginia Tech CPES in the solid-state transformer (SST) research landscape. Kolar joined ETH Zurich in 2001 and led the lab through its emergence as one of the most-cited European research groups in wide-bandgap power electronics. He transitioned to Professor Emeritus status in August 2024 while continuing active SST research.

The ETH Zurich SST research program has emphasized ultra-compact, ultra-efficient wide-bandgap converter systems. Two 15-kilowatt demonstrator systems built and extensively tested at the lab document the achievable power-density frontier: an all-SiC two-level four-switch DC-DC converter at 44 kilowatts per kilogram, and an all-GaN three-level eight-switch DC-DC converter at 86 kilowatts per kilogram. The all-GaN result at 86 kW/kg is among the highest power-density demonstrations achieved in any laboratory in any nation, and is the foundational reference for the Enphase IQ SST commercial product launched in 2026.

Kolar’s research output extends well beyond SST hardware. Active research lines include artificial-intelligence and machine-learning applications in power-electronics control, life-cycle analysis of power-electronics converters, and the bidirectional EV-charging architectures that align directly with commercial vehicle-to-grid (V2G) deployment. The lab’s 250-plus IEEE publications make it one of the most prolific power-electronics research groups in the world.

The Smart All-SiC Solid-State Transformer project, conducted under the ETH Energy Science Center initiative, was one of the early European public demonstrations of a complete all-SiC SST architecture. The project predated several of the commercial all-SiC SST products that ABB, Hitachi Energy, and Eaton-Resilient have subsequently brought to market. The intellectual lineage from ETH Zurich into the European commercial SST industry is direct.

The contrast between ETH Zurich and the US academic centers is in research focus and industry-collaboration model. ETH PES Lab is more concentrated on device-level and converter-level engineering breakthroughs at small-power demonstrator scale. NCSU FREEDM and Virginia Tech CPES have larger system-integration scopes and stronger US-industry coupling. The combined output of all three institutions feeds the global SST industry: roughly half of the senior engineering talent at commercial SST manufacturers trained at one of the three.

Why It Matters

For the research pipeline, ETH Zurich’s Power Electronic Systems Lab under Johann Kolar is the European counterpart to NCSU FREEDM and Virginia Tech CPES, and its focus on ultra-compact, ultra-efficient wide-bandgap converters feeds directly into what commercial SSTs can achieve. Where the most-cited academic groups concentrate is a leading indicator of which converter topologies reach product two to five years out.

Critical Perspective

Editorial correction: This post is part of MGRID’s Solid-State Transformer industry coverage. As of May 2026, that body of work systematically framed manufacturer announcements, funding rounds, and laboratory demonstrations as commercial deployments. The reality is that field-deployed commercial-class SST in revenue service globally is measured in single digits, and almost every product cited in this series is at “announced” or “funded” stage, not “operational.” Readers should treat the specific claims in this post against the standards documented in our SST Industry Reality Check (the per-claim audit table maps marketing language to verifiable deployment status). The corrective article is the canonical reference for SST industry reality; this post remains published with its original framing so the editorial drift is traceable.

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