D
David
Guest
On 10/2/2013 11:57 AM, Phil Allison wrote:
Yes it is.
That is why power utilities install under frequency load shedding
relays. If the power system frequency drops it indicates that the load
exceeds the supply. The under frequency load shed relay sheds some load,
often industrial furnaces, smelters etc, which get special electricity
rates.
David
"Sylvia Else"
On 2/10/2013 8:37 AM, Phil Allison wrote:
"F Murtz"
one article
http://www.project.nsearch.com/profiles/blogs/big-brother-to-switch-off-your-fridge-power-giants-to-make
** You would have to be very stupid to swallow one word of that drivel -
load and supply frequency are NOT related in the simplistic way being
suggested.
Blackouts, when they do occur, are not across the *whole supply grid* but
particular sub stations that experience faults or overheating of the
transformers.
For example: NSW, SA, VIC and QLD are all one grid and so share a common
frequency - which is derived and controlled from hydro generators in the
Snowy mountains.
Anyone who cares to check the frequency will see that variations from
50Hz
are small ( typically +/- 0.1Hz ) and are largely independent of the
time
of day or weather.
FYI.
Tasmania shares power with VIC via an under sea cable - but that cable
uses
DC so the frequency in Tasmania is not locked to the main grid.
A short term drop in frequency is an indicator that power demand is
momentarily exceeding supply.
** No it is not.
... Phil
Yes it is.
That is why power utilities install under frequency load shedding
relays. If the power system frequency drops it indicates that the load
exceeds the supply. The under frequency load shed relay sheds some load,
often industrial furnaces, smelters etc, which get special electricity
rates.
David