Why AC Power Distribution in Data Centers
Why AC Power Distribution in Data Centers
(OP)
For a long time, I've wondered why data centers don't use DC distribution instead of AC. After all, it takes a lot to bring in AC power from the drip, rectify it to DC for the UPS batteries, invert it back to AC, synchronize AC outputs from multiple UPSs, and distribute AC power to the computers, which are just going to rectify it to DC again. It seems to me that this add unnecessary complexity and inefficiency into the system. Why can't they just distribute electrical power as DC within the data center? The telecom industry uses 48VDC. I'm sure there must be a reason, or they would be doing it. Anyone know why?
Engineers are always honest in matters of technology and human relationships. That's why it's a good idea to keep engineers away from customers, romantic interests, and other people who can't handle the truth.






RE: Why AC Power Distribution in Data Centers
Nowadays they like to pick standard systems out of catalogs and combine together, to Hell with the heat and losses.
600 and 750 volt DC systems are still used for subways and tramways and no reason not to have in your data center, it is standard equipment off the shelf from many suppliers. But real juicy arcs when there is a fault...
125VDC is still the standard for battery systems in power stations and substations. Off the shelf equipment.
rasevskii
RE: Why AC Power Distribution in Data Centers
AC power from the utility would be your primary(and maybe secondary)source. As a backup you would have an emergency diesel generator, AC of course, and then finally your DC batter banks and associated DC/AC converters. These batteries are continuously charged by your AC primary source.
RE: Why AC Power Distribution in Data Centers
DC power should be viable. The telephone central offices ran that way for a few decades- utility power backed up by diesel generators all feeding banks of rectifiers charging large battery banks.
Maybe the problem is getting server manufacturer's to use a 48 VDC power source? Is an AC-DC power supply much cheaper than a DC-DC?
RE: Why AC Power Distribution in Data Centers
Below are a couple of articles by my colleagues which discuss DC distribution for data centers.
www.data
RE: Why AC Power Distribution in Data Centers
It is a friend of mine, John Akerlund, that pushes this technology. He was head of a power supply research department at Ericsson Systems and is now doing the same work in his own company UPN. A paper can be found here: http://ww
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Why AC Power Distribution in Data Centers
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Why AC Power Distribution in Data Centers
Data centers use a lot more power than most people think they do.
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies