System optimization of a high power density non-isolated intermediate bus converter for 48 V server applications

With the power architecture transition from a 12 V to 48 V rack in modern data centers there is an increased interest in improving 48 V power conversion efficiency and power density. In this paper, we will analyze system optimization for a 48 V to 12 V non-isolated, fully regulated, intermediate bus converter (IBC) to maximize efficiency and power density. The final experimental prototype, a fully regulated, digitally controlled, 720 W, five phase, GaN transistor based 48 V to 12 V buck IBC demonstrates exceptional efficiency and power density, respectively exceeding 95% and 1000 W/in3.

[1]  J. Glaser,et al.  GaN Transistors for Efficient Power Conversion , 2019 .

[2]  David Reusch,et al.  High Frequency, High Power Density Integrated Point of Load and Bus Converters , 2012 .

[3]  Sergio Saponara,et al.  Design and Measurement of Integrated Converters for Belt-Driven Starter-Generator in 48 V Micro/Mild Hybrid Vehicles , 2017, IEEE Transactions on Industry Applications.

[4]  David Reusch,et al.  Evaluation of gate drive overvoltage management methods for enhancement mode gallium nitride transistors , 2017, 2017 IEEE Applied Power Electronics Conference and Exposition (APEC).

[5]  Fred C. Lee,et al.  A high frequency core loss measurement method for arbitrary excitations , 2011, 2011 Twenty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  T. Wilson,et al.  A calorimetric method for measurement of total loss in a power transformer , 1991, PESC '91 Record 22nd Annual IEEE Power Electronics Specialists Conference.

[7]  Fred C. Lee,et al.  48-V Voltage Regulator Module With PCB Winding Matrix Transformer for Future Data Centers , 2017, IEEE Transactions on Industrial Electronics.

[8]  Robert C. N. Pilawa-Podgurski,et al.  A resonant switched capacitor based 4-to-1 bus converter achieving 2180 W/in3 power density and 98.9% peak efficiency , 2018, 2018 IEEE Applied Power Electronics Conference and Exposition (APEC).

[9]  J. Strydom,et al.  Understanding the effect of PCB layout on circuit performance in a high frequency gallium nitride based point of load converter , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[10]  Chenhao Nan,et al.  Switched tank converters , 2018, 2018 IEEE Applied Power Electronics Conference and Exposition (APEC).

[11]  C.R. Sullivan,et al.  Improved calculation of core loss with nonsinusoidal waveforms , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[12]  Chenhao Nan,et al.  Switched tank converter based partial power architecture for voltage regulation applications , 2018, 2018 IEEE Applied Power Electronics Conference and Exposition (APEC).

[13]  David Reusch,et al.  System Optimization of a High Power Density Non-Isolated Intermediate Bus Converter for 48 V Server Applications , 2019, IEEE Transactions on Industry Applications.

[14]  Alireza Khaligh,et al.  A High Step-Down Dual Output Nonisolated DC/DC Converter With Decoupled Control , 2018, IEEE Transactions on Industry Applications.

[15]  Chenhao Nan,et al.  A high efficiency resonant switched-capacitor converter for data center , 2017, 2017 IEEE Energy Conversion Congress and Exposition (ECCE).

[16]  Johan Strydom,et al.  High Power Fully Regulated Eighth-brick DC-DC Converter with GaN FETs , 2015 .

[17]  A. W. Kelley,et al.  An improved calorimeter for measuring the core loss of magnetic materials , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).

[18]  J. Strydom,et al.  Thermal evaluation of chip-scale packaged gallium nitride transistors , 2016, 2016 IEEE Applied Power Electronics Conference and Exposition (APEC).

[19]  Charles R. Sullivan,et al.  Measurements and Performance Factor Comparisons of Magnetic Materials at High Frequency , 2015, IEEE Transactions on Power Electronics.