On 01/05/13 01:58, F Murtz wrote:
Dave Liquorice wrote:
On Mon, 29 Apr 2013 12:55:31 +0100, The Other Mike wrote:

http://www.dailymail.co.uk/news/arti...rother-switch-
fridge-Power-giants-make-millions--pay-sinister-technology.html

I know it's the Mail but WTF do you start with the ******** it spouts.

"Can shut down supply without warning - or your consent"

There will be something buried in the User Guide that gives your consent
by the simple act using the appliance. That happens already for lots of
things.

In the graphic it says demand surged during the Royal Wedding. I
doubt it
was during but immediatly afterwards when everyone leapt up for a cuppa
and a wee (pumps coming on to supply water and take it away). Not even
sure that 2.4 GW is correct either and if it is it's probably one of, if
not the, largest load pickups ever and can be planned for and is why we
have Dinorwic.

"Sensors in domestic appliances would check this frequency every 0.2
seconds, and if it fell to 47Hz - a level that would risk blackouts -
the
devices would kick in and shut fridges, freezers and ovens down."

Only "risk" blackouts at 47 Hz? The limit 50 Hz is +/- 0.5 Hz. I reckon
if it ever got down to 47 Hz there would be power stations tripping out
left right and center.

"If the frequency of the supply nudged towards 52 Hz, the devices could
make fridges become cooler, increasing demand and balancing out the
system."

Pardon, do I really see what I'm reading? HTF can a switch make a device
use more energy? Or are they saying it switches on when it doesn't need
to?

"'It will have no material impact on the operation of fridges and
freezers switching will be for a few seconds and only occasionally.'"


If it shut down for a few seconds, would not it use more energy
switching back on again than it saved by switching off?


that is possible.
high current transients cause extra losses in power lines because its I
squared R, So delivering the same average power down a resistive line is
less efficient at lower duty cyles.

When the idea s to use less power overall, its rather more complex.

A problem many have encountered in the RC electric plane world, where
controllers blow up at part throttle, not full (throttling being done
by chopping the supply) .Its critically linked to the leakage inductance
of the motors: low inductance (the best motors) will have massive peak
currents at part throttle.



Well if they don't cut in until 47 Hz I think "occasionally" is
likely to
be "never" or if they do will they switch the appliance off before the
supply anyway.

Very much looks like the unelected bureaucrats in Brussels have been
taken to some very nice meals.




--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.