power failure causes and effects

Fri Aug 15 05:17:34 UTC 2003

We have power in some pops and our co.. Genie just shut off.. Wow its quiet
now.. (fyi our co is in vaughan).

mark

--
Mark Segal 
Director, Network Planning
FCI Broadband 
Tel: 905-284-4070 
Fax: 416-987-4701 
http://www.fcibroadband.com

Futureway Communications Inc. is now FCI Broadband

-----Original Message-----
From: Mehmet Akcin [mailto:mehmet at akcin.net] 
Sent: August 15, 2003 1:10 AM
To: nanog at merit.edu
Subject: Re: power failure causes and effects

I have been hearing on the TV that some places that had power failure have
started getting their power back, reporters say hopefully by the morning all
of the places where had power failure will back online.

Mehmet Akcin

----- Original Message ----- 
From: "Marshall Eubanks" <tme at multicasttech.com>
To: "Fred Heutte" <aoxomoxoa at sunlightdata.com>; <nanog at merit.edu>
Sent: Friday, August 15, 2003 12:51 AM
Subject: Re: power failure causes and effects

>
> On Thu, 14 Aug 2003 19:12:04 -0700
>  Fred Heutte <aoxomoxoa at sunlightdata.com> wrote:
>
> It looks like DC may have had a close call - the University of 
> Maryland
was
> dark for about 1 hour, and I have heard several news reports here 
> stating that the local (DC regional) power grid just managed to 
> decouple from wider East Coast grid in time to avoid a collapse here.
>
> Regards
> Marshall Eubanks
>
> >
> > Most of the early rumors about causes of the power failure have 
> > proven incorrect -- fire at a New York City power plant, etc.
> >
> > Most likely is a congestion failure in the Niagara-Mohawk grid, 
> > which covers a large part of New York state and has feeders across 
> > into Canada.
> >
> > Congestion failures happen when power flows through a particular 
> > switching station are high, and a component fails either directly or 
> > because of a power surge caused by a failure elsewhere.
> >
> > The imbalance caused by an open or short circuit will then 
> > immediately spread through the rest of the grid unless action is 
> > taken to disconnect, or point failures occur (resulting in fires and 
> > explosions from degradation of power transmission equipment, 
> > transformers, etc., not a pretty outcome at all) -- or both.  In 
> > general, transmission grids are designed from a failsafe 
> > perspective, meaning that it is much safer to cause rolling 
> > brownouts or blackouts than to let key components such as 
> > transmission substations or power plants have a catastrophic 
> > failure.
> >
> > Since the entire grid has to be in sync and supply and demand must 
> > be in relative parity at all times, the usual strategy in these 
> > cases is to isolate the affected area, "island it" by shutting down 
> > power ingress and egress (tripping safety breakers at major crossing 
> > points), and shutting down power plants in the vicinity that will 
> > have stress failures if they don't have sufficient load to balance 
> > their output.
> >
> > The problem is that power travels faster than even the highest-speed 
> > switching equipment can operate, so the surges causing a cascading 
> > failure like this afternoon's can spread very quickly, like ripples 
> > in a pond.
> >
> > The weather was hot and humid but completely within
> > range for the time of year, so this has to be counted as a "normal 
> > accident."  It's likely that whatever component initially failed and 
> > triggered the shutdown was within its usual tolerances and simply 
> > had an ordinary breakdown. Of course, to spread, a massive outage 
> > like this also exposes other weaknesses and hidden dependencies in 
> > the system, which might be other physical components, software,
> > operator error, etc.
> >
> > The system is remarkably resilient in most circumstances, which is 
> > what five-nines or more is all about.  But rust never sleeps, and 
> > underinvestment in key transmission corridors in New England, New 
> > York north of Manhattan and in parts of the Midwest is no doubt an 
> > underlying cause.
> >
> > As to the root cause of that engineering problem -- the answer is 
> > politics, some of it congressional, and I will say no more in this 
> > forum.
> >
> > Fred Heutte
> >
> > Portland, Oregon
> > energy policy analyst and net geek
> >
>