[142437] in North American Network Operators' Group
Re: Wacky Weekend: NERC to relax power grid frequency strictures
daemon@ATHENA.MIT.EDU (Michael DeMan)
Sun Jun 26 00:01:37 2011
From: Michael DeMan <nanog@deman.com>
In-Reply-To: <20110625221208.GA64593@ussenterprise.ufp.org>
Date: Sat, 25 Jun 2011 21:01:50 -0700
To: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
It ismy understanding also that most commercial grade gensets have built int=
o the ATS logic that when utility power comesback online, that the transfer b=
ack to utility power is coordinated with the ATS driving the generator until=
both frequency and phases are within a user specified range?
- mike
On Jun 25, 2011, at 3:12 PM, Leo Bicknell <bicknell@ufp.org> wrote:
> In a message written on Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashwort=
h wrote:
>> I believe the answer to that question is contained here:
>>=20
>> http://yarchive.net/car/rv/generator_synchronization.html [1]
>=20
> I wouldn't use a colo that had to sync their generator to the grid.
> That is a bad design.
>=20
> Critical load should be on a battery or flywheel system. When the
> utility is bad (including out) the load should be on the battery or
> flywheel for 5-15 seconds before the generators start. The generators
> need to sync to each other.
>=20
> Essential load (think lighting, AC units) get dropped completely for
> 30-60 seconds until the generators are stable, and then that load gets
> hooked back in.
>=20
> I have never seen a generator that syncs to the utility for live, no
> break transfer. I'm sure such a thing exists, but that sounds crazy
> dangerous to me. Generators sync to each other, not the utility.
>=20
> --=20
> Leo Bicknell - bicknell@ufp.org - CCIE 3440
> PGP keys at http://www.ufp.org/~bicknell/
