Novel Isolated-Three-Phase-HF-Link Matrix-Type Three-Phase AC/DC Converter (i3X-Rectifier)

The rapid expansion of AI-driven data centers is significantly increasing the demand for ultra-efficient high-power three-phase (3-Φ) mains-connected single-stage ac/dc conversion solutions, featuring sinusoidal input current, galvanic isolation, and controlled output voltage. Conventional isolated-single-phase-HF-link matrix-type 3-Φ ac/dc converters encounter critical challenges at high power levels due to high component stresses. As a result, a relatively large number of low-power modules must be paralleled within a single 1 MW power rack, increasing system complexity and reducing reliability. To address this limitation, this paper introduces a novel isolated-three-phase-HF-link matriX-type three-phase ac/dc converter (i3X-Rectifier) that lowers individual component stresses and/or enhances power conversion efficiency and volumetric density in high-power, i.e., 100 kW range, data center power supplies. Utilizing a three-phase galvanic isolation transformer combined with either a direct or indirect matrix-type front-end, the proposed i3X-Rectifier enables single-stage (direct) conversion from 3-Φ low-frequency (LF) mains voltages to 3-Φ high-frequency (HF) transformer voltages, advantageously resulting in significantly reduced current stresses in main active and passive components and minimized filtering efforts. Furthermore, the proposed i3X-Rectifier supports quasi-current-dc-link operation, enabling generation of sinusoidal 3-Φ mains currents using conventional low-switching-loss current dc-link 2/3-PWM, simplifying modulation and reducing control complexity. Comprehensive closed-loop circuit simulations and comparative analyses of the proposed concept against the conventional isolated-single-phase-HF-link approach validate the substantial performance advantages of the proposed i3X-Rectifier, highlighting its suitability for next-generation high-power, high-efficiency data center power supply architectures.