Enphase Energy, Inc. has demonstrated its IQ Solid-State Transformer (IQ SST), converting 13.8 kV AC to 800 VDC in a system designed for AI data center power. The demonstration at the company's research and development lab in Austin, Texas, maintained a stable 800 VDC output through load steps simulating the fast-changing demands of AI compute racks.
By converting medium-voltage AC directly to 800 VDC, IQ SST is designed to eliminate multiple conversion stages in conventional data center power architectures, reducing conversion losses and making more power available for AI compute.
The test system used 132 power modules, with 44 connected in series on each of three phases. Each module handled a few hundred volts, so no single module saw the full 13.8 kV. Enphase's distributed controls maintained balanced voltage sharing across the modules and coordinated their response to rapid load changes. The architecture is designed to continue operating if an individual power module fails.
Each 5.5 kW-rated power module combines gallium nitride (GaN) power switching, Enphase's fifth-generation Kestrel ASIC, and a proprietary high-frequency transformer developed by the company's in-house magnetics team. The modules use components and manufacturing processes similar to those in Enphase IQ Microinverters. The first IQ SST power modules are being built at Enphase's manufacturing facility in Arlington, Texas.
Hans van Antwerpen, chief technology officer at Enphase Energy, said: “All 132 modules shared the voltage evenly, and the 800 V output held steady through every load step. The architecture scales by adding power modules in series, so 13.8 kV gives us a clear path to 34.5 kV.”
Enphase plans to extend the demonstration to 34.5 kV in the coming weeks. The company expects to demonstrate full-system IQ SST racks operating at megawatt scale and rated power before the end of 2026, with customer pilots planned for 2027.
