@article{wong_zhu_pahl_bhattacharya_2021, title={Design and Implementation of 50V/400A Single-Stage Full-Bridge Synchronous Rectifier for Data Center Application}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595179}, abstractNote={Synchronous rectification (SR) is widely adopted for low-voltage high-current applications to improve efficiency. However, most SR researches focus on low power levels at hundreds or several kilowatts, and there is yet any attempt to extend SR to tens of kilowatts. This paper presents the design and experimental results of a full-bridge SR using ON-Semi NCP4305 SR IC at 20kW for 48V data center application.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Wong, Isaac and Zhu, Guangqi and Pahl, Birger and Bhattacharya, Subhashish}, year={2021}, pages={2245–2250} }
 @article{zhu_pahl_wong_samanta_bhattacharya_2021, title={High Efficiency Medium Voltage to Low Voltage Wireless Power Transformation for Data Centers}, ISSN={["1048-2334"]}, DOI={10.1109/APEC42165.2021.9487222}, abstractNote={Wireless power transfer (WPT) techniques have been widely explored for various applications including for electric vehicles (EVs) and mobile phones. Less attention has been paid to the use of WPT in power distribution applications. An isolated wireless power link enables a touch safe interface without electrically energized contacts eliminating any arc flash or electrocution hazards. This concept will for example enable safe medium voltage distribution inside data centers eliminating low voltage distribution with its large bus bars and cables and bring voltages larger than 1kV directly to the server rack. It has been demonstrated that a converter using a planar contactless transformer can directly convert the 1kV DC input to 48V over a wide load range. In this paper, the planar contactless transformer is optimized with 3D printed bobbins to improve the manufacturability and technology readiness level. A new synchronous rectifier architecture is developed with MOSFET drain-to-source voltage-sensing for an H-bridge rectifier to improve the DC-to-DC efficiency. An adaptive dead time control method is used to compensate for layout parasitic inductances, to maximize the synchronous rectifier efficiency, and to avoid premature turn-off of MOSFETs. The DC-to-DC power transfer efficiency and loss distribution are analyzed.}, journal={2021 THIRTY-SIXTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2021)}, author={Zhu, Guangqi and Pahl, Birger and Wong, Isaac and Samanta, Suvendu and Bhattacharya, Subhashish}, year={2021}, pages={1580–1585} }
 @article{zhu_pahl_fons_wong_bhattacharya_beddingfield_2021, title={Medium Voltage to Low Voltage Contactless Power Transformation for Data Centers}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595112}, abstractNote={Contactless power transfer (CPT) methods have widely been explored for many applications. An isolated wireless power link enables a touch-safe interface without electrically energized contacts eliminating any arc flash or electrocution hazard. The concept presented here will enable safe medium voltage distribution inside data centers eliminating low voltage distribution with bulky cables bringing voltages larger than 1kV directly to the server rack. This paper proposes high-efficiency single-stage contactless power conversion from medium voltage to low voltage for data center applications. The proposed solution is evaluated using a 10kW design example and verified by experimental tests. A plug-in contactless transformer is developed with customized nanocrystalline cores and 3D printed bobbins to improve the DC-to-DC efficiency and manufacturability. A high efficiency converter is developed to maintain a 48V output voltage with a IOOOV input voltage over a wide load range. The DC-to-DC efficiency and frequency modulation performance are analyzed.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Zhu, Guangqi and Pahl, Birger and Fons, Richard J. and Wong, Isaac and Bhattacharya, Subhashish and Beddingfield, Byron}, year={2021}, pages={5839–5844} }