Voltage Reduction Test February 7 (Ontario only)

[David van Geest]

On Tue, Jan 31, 2012 at 2:05 PM, D. Hugh Redelmeier <hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org> wrote:
> | From: Walter Dnes <waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org>
>
> | >  There will be a three percent voltage reduction
> | > test between 9:00 and 10:00 EST, followed by a five percent test
> | > between 13:00 and 14:00 EST.
>
> There was a 5 minute power failure in our neighbourhood at 9:30.  And
> another short one at 10:46.
>
> I don't imagine that they were connected with the test.  More likely
> to do with the hydraulic excavator that is digging down 5m or more on
> the road at our driveway today.

Well, given that the test is scheduled for Feb. 7, I doubt your outage
was connected to the test too :-).

> | >  The IESO will measure the electricity
> | > load reduction resulting from these voltage changes.
>
> I'd expect some loads to go up.  Power transmission at lower voltage
> is less efficient and some things (like computers) take a certain
> amount of power, whatever the voltage is (within reason).

If the input voltage to a computer goes down, but the computer
requires constant power, then the PS will draw more current (P = IV).
Power would remain constant.  The IESO says that overall load goes
down by 500 MW (http://www.ieso.ca/imoweb/siteShared/voltage_reduction.asp?sid=bi),
so it would seem that the resistance load is significant.

>
> Simple restance thingees, like baseboard heaters, water heaters,
> ordinary electric stoves, and incandescent lightbulbs would use less
> power (but some would lengthen their on time to compensate).

True, but since it's an emergency measure designed to reduce
instantaneous load, it doesn't matter if they stay on longer.
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists