Advanced Datacenter AC/DC Distribution and Conversion Power Architecture

Author: Panel: Desheng Guo (Texas Instruments), Niannian Cai (Google), Ehsan Nasr (Microsoft), Jing Wang (Google), Ruslan Nagimov (Microsoft); Moderator: Saket Karajgikar Collection: 2025 OCP Global Summit - Data Center Facility

Summary

This panel session features five presentations addressing the fundamental challenge of delivering power to AI data center racks as densities scale from hundreds of kilowatts to megawatts per rack. The session covers the full spectrum of emerging power architecture solutions: Texas Instruments presents a 30 kW AC-to-HVDC reference design using flying capacitor PFC topology with 98.5% peak efficiency; Google proposes microgrid controls plus battery energy storage systems (BESS) to address AI/ML load fluctuations and grid instability; Microsoft frames the system-level problem statement for solid state transformers (SST) and energy infrastructure innovation; Google details a low-voltage DC (LVDC) distribution architecture using SSTs converting from 34.5 kV medium voltage AC to plus/minus 750 V DC, with a 1 MW proof-of-concept already energized at 13.8 kV to plus/minus 400 V; and Microsoft presents superconducting power architectures using high-temperature superconducting (HTS) cables that could eliminate distance constraints and enable disaggregated power plants.

The presenters collectively argue that conventional power architectures cannot sustain the exponential growth in AI compute density. Rack power is projected to increase from hundreds of kilowatts to 1000s of kilowatts (megawatt-class), requiring order-of-magnitude innovation rather than incremental steps. The key architectural shift is disaggregation of power conversion from IT racks into sidecars or facility-level systems, combined with adoption of higher DC voltages (400/800/1500 V) at the rack. Google has already proven the SST concept at 1 MW in its own data center test lab in 2025, and is promoting plus/minus 750 V DC as a forward-looking standard that accommodates both current 800 V rack designs and future 1500 V DC targets. Microsoft advocates superconductors as a longer-term solution, noting that a 4-inch superconducting feeder can replace a 2-foot by 4,000 A copper busway, enabling power plants to be located on separate parcels from data halls.