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.

Keywords

• Differential power processing
• Data centers
• Topology
• Architecture
• Dual active bridge
• Flyback