Enphase Energy has demonstrated its IQ Solid-State Transformer (IQ SST) technology converting 13.8 kV AC to 800 VDC in its R&D lab in Austin, Texas. The company framed the test around AI data center power delivery, with load steps intended to simulate fast-changing AI compute rack demand.
The demonstration system used 132 power modules, with 44 connected in series on each of three phases, operating together as a single system. Enphase said the setup maintained a stable 800 VDC output through the load-step testing.
Instead of asking a single device to withstand the full 13.8 kV, the architecture spreads the voltage across modules, with each module handling “a few hundred volts.” Enphase said distributed controls maintained balanced voltage sharing across all 132 modules and coordinated the response to rapid load changes to keep the output within specification. The design is also intended to be redundant, continuing operation if an individual power module fails.
Each power module is rated at 5.5 kW and combines gallium nitride (GaN) power switching, Enphase’s fifth-generation Kestrel ASIC, and a proprietary high-frequency transformer developed by Enphase’s in-house magnetics team. Enphase also said the modules use similar components and manufacturing processes to those used in its IQ Microinverters, and that the first IQ SST power modules are already being built at its manufacturing facility in Arlington, Texas.
For data center power engineers, medium-voltage AC to 800 VDC conversion is an attempt to cut out some of the conversion stages typical in conventional architectures. Enphase’s stated goal is fewer conversion steps, lower conversion losses, and more power delivered to AI compute, but the real bar will be repeatable performance at scale, protection coordination, and serviceability under data center operating constraints.
“All 132 modules shared the voltage evenly, and the 800 V output held steady through every load step,” said Hans van Antwerpen, chief technology officer at Enphase Energy, adding that the company views the modular series approach as a scaling path: “13.8 kV gives us a clear path to 34.5 kV.” Raghu Belur, co-founder and chief product officer, said the company is applying its power electronics experience to AI data centers and “delivering power more efficiently to AI compute racks.”
Enphase said it plans to extend the demonstration to 34.5 kV in the coming weeks, and 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. More information is available on Enphase’s website.
Source: Enphase Energy
