400-V dc distribution is rising in telecom

It seems like a natural idea. New power architectures, such as those based around 400 Vdc, can be a more efficient means of power distribution because they eliminate the conversion loss inherent in every power supply that converts grid ac into dc for use in electronics and most appliances. Those losses add up in power-hungry facilities such as server farms and telecommunication hubs.

The impetus for high-voltage dc distribution became more compelling with the development of efficient power semiconductors and new power conversion topologies able to efficiently convert the high dc voltages into lower levels for use in ordinary circuitry. And the release in February 2012 of the European Telecommunications Standards Institute EN 300 132-3-1 standard for 400-Vdc set the stage for applications in this area and for more detailed standards. The EN 300 132-3-1 standard covers the requirements for the interface between telecommunications and datacom (ICT) equipment and its power supply and also includes requirements relating to power supply stability and measurement.

Experts say 400 Vdc is particularly suited for high-power delivery over long distances because it reduces the amount of copper wire needed for electrical cable by as much as 80% compared to that for an ac system, with a commensurate increase in efficiency inherent in lower line losses.

Recently, power conversion vendors got together at an event called Intelec to put together a demonstration system that would show how higher voltage dc power distribution frameworks can use contemporary power conversion technologies and architectures to make 400 Vdc practical.

“400-Vdc distribution technology promises a host of benefits for telecom and datacenter applications, with the potential for greater conversion efficiency and lower operating costs than conventional power distribution schemes,” said Gary Niederpruem, vice president Marketing & Business Development at, Emerson Network Power’s Energy Systems business, a participant in the live demonstration. “With this demonstration, featuring our NetSure 4015 DC Power System, we hope to advance a fruitful industry dialogue focused on the merits and viability of 400 VDC distribution.”

The Intelec demonstration system employed VI Chip power modules and Factorized Power Architecture (FPA) from power systems maker Vicor Corp. Sporting bus conversion efficiencies up to 97%, VI Chip power modules convert input voltages up to 400 V to the 12 or 48 V used for powering telecom and datacenter hardware. The Vicor Factorized Power Architecture, using VI Chips, among other things provided conversion systems with fewer power conversion stages than has historically been the case.

Vicor put together a whitepaper on higher voltage dc distribution architectures for telecom and datacenter applications. It also created a video of the 400 Vdc demo at Intelec 2012:

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