Differential power processing for data centers applications: A comprehensive review

Abstract The number of data centers worldwide has been growing exponentially to serve a multitude of aspects of modern life. The major challenges that face data centers operators are the rising electricity bills, growing carbon footprints, and unexpected power outages. An effective approach to tackle such problems is to investigate the implementation of efficient power supplies that offers the rack voltage levels required to power servers. Recently, the differential power processing (DPP) concept proved to potentially offer less number of cascaded stepping down stages by connecting the servers in series and introducing a DPP converter to supply or withdraw current mismatch in the series connection. DPP system can replace the conventional two-stage power electronics converter with an efficiently designed converter. Thus, the series stacking power delivery architecture is proposed with efficient Gallium Nitride (GaN) based power electronics converters to reduce the system size and losses. The introduced review in this paper aims to give the reader a comprehensive understanding of DPP implementation for data centers in terms of the possible series stacking architecture, converter types and switch types. The advantages and disadvantages of each architecture are discussed along with the most commonly employed DPP converters in various applications. Further investigation on the cost-effectiveness and commercialization of GaN-based series stacking architecture still needs further investigation and deployment.

[1]  Taewon Kim,et al.  Design Methodology of Bidirectional Flyback Converter for Differential Power Processing Modules in PV Applications , 2019, 2019 10th International Conference on Power Electronics and ECCE Asia (ICPE 2019 - ECCE Asia).

[2]  Enver Candan A series-stacked power delivery architecture with isolated converters for energy efficient data centers , 2014 .

[3]  P. T. Krein,et al.  Differential power processing architecture for increased energy production and reliability of photovoltaic systems , 2012, 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[4]  Leon M. Tolbert,et al.  Wide bandgap power devices based high efficiency power converters for data center application , 2014, 2014 IEEE Workshop on Wide Bandgap Power Devices and Applications.

[5]  D. Maksimovic,et al.  Architectures and Control of Submodule Integrated DC–DC Converters for Photovoltaic Applications , 2013, IEEE Transactions on Power Electronics.

[6]  Jason T. Stauth,et al.  Efficient Voltage Regulation for Microprocessor Cores Stacked in Vertical Voltage Domains , 2016, IEEE Transactions on Power Electronics.

[7]  P. T. Krein,et al.  Differential Power Processing for Increased Energy Production and Reliability of Photovoltaic Systems , 2013, IEEE Transactions on Power Electronics.

[8]  Christian Kral,et al.  A Current Equalization Method for Serially Connected Battery Cells Using a Single Power Converter for Each Cell , 2011, IEEE Transactions on Vehicular Technology.

[9]  Dragan Maksimovic,et al.  Performance of Mismatched PV Systems With Submodule Integrated Converters , 2014, IEEE Journal of Photovoltaics.

[10]  Robert C. N. Pilawa-Podgurski,et al.  Enhancing Microinverter Energy Capture With Submodule Differential Power Processing , 2016, IEEE Transactions on Power Electronics.

[11]  Robert C. N. Pilawa-Podgurski,et al.  A series-stacked power delivery architecture with hot-swapping for high-efficiency data centers , 2015, 2015 IEEE Energy Conversion Congress and Exposition (ECCE).

[12]  Young-Tae Jeon,et al.  Unit-Minimum Least Power Point Tracking for the Optimization of Photovoltaic Differential Power Processing Systems , 2019, IEEE Transactions on Power Electronics.

[13]  Robert C. N. Pilawa-Podgurski,et al.  Decoupled and Distributed Maximum Power Point Tracking of Series-Connected Photovoltaic Submodules Using Differential Power Processing , 2015, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[14]  J. Strydom,et al.  Evaluation of Gallium Nitride Transistors in High Frequency Resonant and Soft-Switching DC–DC Converters , 2015, IEEE Transactions on Power Electronics.

[15]  R. C. N. Pilawa-Podgurski,et al.  Sub-module differential power processing for photovoltaic applications , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[16]  Fang Zhuo,et al.  An Improved Submodule Differential Power Processing-Based PV System With Flexible Multi-MPPT Control , 2018, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[17]  Philip T. Krein,et al.  Converter Rating Analysis for Photovoltaic Differential Power Processing Systems , 2015, IEEE Transactions on Power Electronics.

[18]  M. D. Seeman,et al.  Resonant Switched-Capacitor Converters for Sub-module Distributed Photovoltaic Power Management , 2013, IEEE Transactions on Power Electronics.

[19]  Philip T. Krein,et al.  Differential Power Processing for DC Systems , 2013, IEEE Transactions on Power Electronics.

[20]  Jason T. Stauth,et al.  Multilevel Power Point Tracking for Partial Power Processing Photovoltaic Converters , 2014, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[21]  Ehsan Adib,et al.  Increasing Energy Capture From Partially Shaded PV String Using Differential Power Processing , 2019, IEEE Transactions on Industrial Electronics.

[22]  Robert C. N. Pilawa-Podgurski,et al.  Hot-Swapping Analysis and Implementation of Series-Stacked Server Power Delivery Architectures , 2017, IEEE Transactions on Power Electronics.

[23]  S. T. Cady,et al.  A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Submodule Differential Power Processing , 2015, IEEE Transactions on Power Electronics.

[24]  Huiqing Wen,et al.  Performance of Submodule Level Differential Power Processing Architecture in Mismatched PV Systems , 2019, 2019 IEEE 10th International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[25]  Hoejeong Jeong,et al.  Review of Differential Power Processing Converter Techniques for Photovoltaic Applications , 2019, IEEE Transactions on Energy Conversion.

[26]  Robert C. N. Pilawa-Podgurski,et al.  A reliability assessment of series-stacked servers with server-to-bus differential power processing , 2016, 2016 IEEE International Telecommunications Energy Conference (INTELEC).

[27]  Robert C. N. Pilawa-Podgurski,et al.  A Resonant Switched-Capacitor Converter With GaN Transistors for High-Efficiency Power Delivery to Series-Stacked Processors , 2020, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[28]  Johann W. Kolar,et al.  Accurate Power Loss Model Derivation of a High-Current Dual Active Bridge Converter for an Automotive Application , 2010, IEEE Transactions on Industrial Electronics.

[29]  Dragan Maksimovic,et al.  Performance of Power-Limited Differential Power Processing Architectures in Mismatched PV Systems , 2015, IEEE Transactions on Power Electronics.

[30]  Young-Tae Jeon,et al.  Least Power Point Tracking Method for Photovoltaic Differential Power Processing Systems , 2017, IEEE Transactions on Power Electronics.

[31]  Olivier Trescases,et al.  SiC-Based Bidirectional Ćuk Converter With Differential Power Processing and MPPT for a Solar Powered Aircraft , 2015, IEEE Transactions on Transportation Electrification.