S
Suzy
Guest
meter is natty.
E
Elmo
Guest
Phil Allison wrote:
supplied by the machines already online, another unit is brought onto
the grid. Normally some units produce less than their full capacity to
give what is called "spinning reserve". The spinning reserve on the grid
is normally at least equal to the largest unit on the grid so that if a
machine trips off there is enough reserve capacity on the grid to cover
it. When demand exceeds the total capacity of the grid you get "brown
outs". This is done by a system controller switching off an area for a
while to reduce grid load. It's simply a matter of operating a switch
which causes a huge circuit breaker to open and cuts of power to a
suburb or small town. Brown-outs are rotated to different areas so as to
reduce inconvenience to customers, but power utitiltys usually have
pre-arranged contracts in place to cut off non-essential loads first.
When a unit does trip off accidently, the grid frequency may drop a few
hertz for a few seconds until the spinning reserve picks up the load,
but you wouldn't be able to forecast a problem in advance, you would
only know of the event afterwards when the frequency has dipped.
In general, bigger grids are more stable.
Elmo
I'm afraid Phil is right. As the load increase beyond what can be
supplied by the machines already online, another unit is brought onto
the grid. Normally some units produce less than their full capacity to
give what is called "spinning reserve". The spinning reserve on the grid
is normally at least equal to the largest unit on the grid so that if a
machine trips off there is enough reserve capacity on the grid to cover
it. When demand exceeds the total capacity of the grid you get "brown
outs". This is done by a system controller switching off an area for a
while to reduce grid load. It's simply a matter of operating a switch
which causes a huge circuit breaker to open and cuts of power to a
suburb or small town. Brown-outs are rotated to different areas so as to
reduce inconvenience to customers, but power utitiltys usually have
pre-arranged contracts in place to cut off non-essential loads first.
When a unit does trip off accidently, the grid frequency may drop a few
hertz for a few seconds until the spinning reserve picks up the load,
but you wouldn't be able to forecast a problem in advance, you would
only know of the event afterwards when the frequency has dipped.
In general, bigger grids are more stable.
Elmo
P
Phil Allison
Guest
"Suzy"
"Phil Allison"
The folk behind that site have NO credibility and have given NO proof of
their claims.
The idea put forward that individual appliances ought to dance to the tune
of tiny variations in the AC frequency is
UTTERLY LUNATIC !!!
A typical fuckwit greenie idea.
Like banning incandescent bulbs and transformer plug packs.
........ Phil
"Phil Allison"
** I will not answer dumb questions or engage in pointless chat.
The folk behind that site have NO credibility and have given NO proof of
their claims.
The idea put forward that individual appliances ought to dance to the tune
of tiny variations in the AC frequency is
UTTERLY LUNATIC !!!
A typical fuckwit greenie idea.
Like banning incandescent bulbs and transformer plug packs.
........ Phil
E
Elmo
Guest
Suzy wrote:
speed limit, you will vary somewhere around the desired setpoint.
Generators use PID controllers to maintain correct load but there will
still be variations due to time lag of the system and over-correction by
the controller. On a big grid these variations will be smaller.
Slightly off topic but interesting, the grid load on a typical week day
has a sharp peak at exactly 6PM.
Elmo
Balancing a load is always difficult, like driving a car at exactly the
speed limit, you will vary somewhere around the desired setpoint.
Generators use PID controllers to maintain correct load but there will
still be variations due to time lag of the system and over-correction by
the controller. On a big grid these variations will be smaller.
Slightly off topic but interesting, the grid load on a typical week day
has a sharp peak at exactly 6PM.
Elmo
B
briang
Guest
"Suzy" <not@valid> wrote
***** Oh dear,haven't you ever heard of a governor and what is designed to
do??
Perhaps your email address says it all!
Brian G.
alternator shaft speed and thus frequency, and vice-versa?
***** Oh dear,haven't you ever heard of a governor and what is designed to
do??
Perhaps your email address says it all!
Brian G.
S
Suzy
Guest
"Elmo" <elmo@sesame.com> wrote in message
news:47c20832$1_2@news.peopletelecom.com.au...
not by looking at a drop in frequency)?
news:47c20832$1_2@news.peopletelecom.com.au...
Yes, that's what I meant. BTW, how do you know when the sharp peak is (if
not by looking at a drop in frequency)?
E
Elmo
Guest
David L. Jones wrote:
concerned with fluctuations and differentials than the actual frequency.
Elmo
For Suzys purposes it doesn't have to be calibrated, she's more
concerned with fluctuations and differentials than the actual frequency.
Elmo
P
Phil Allison
Guest
"Suzy" = not@valid
** ROTFL !!!
Better go learn about ohms law - honey ...
....... Phil
** ROTFL !!!
Better go learn about ohms law - honey ...
....... Phil
S
Suzy
Guest
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:62ef24F23a541U1@mid.individual.net...
Americanly. But I put it to you in good faith as I thought I detected a
smidgeon of real knowledge and was willing to be corrected if you had a
point to make. More and more you show about 1% of knowledge mixed with 99%
or baseless abuse.
rational discussion. How do you set yourself up as judge of the credibility
of others? I wonder what your qualifications and proven experience are?
"pointless chat".
What a pity you have no tolerance for mere mortals.
news:62ef24F23a541U1@mid.individual.net...
What a pompous answer! It is true and is not "dumb" as you assert
Americanly. But I put it to you in good faith as I thought I detected a
smidgeon of real knowledge and was willing to be corrected if you had a
point to make. More and more you show about 1% of knowledge mixed with 99%
or baseless abuse.
Have you any credibility with this displayed inability to enter into a
rational discussion. How do you set yourself up as judge of the credibility
of others? I wonder what your qualifications and proven experience are?
Sound quite plausible to me. Wouldn't bother with a toaster though...
Back to normal
I agree with you about that, but no doubt to you (o mighty one) it is
"pointless chat".
What a pity you have no tolerance for mere mortals.
E
Elmo
Guest
Suzy wrote:
load graph. We can bring up load data going back several years. It's
only updated every ten minutes. I haven't looked at the frequency
recordings for ages but I'll have a look when I go back to work.
The load generally rises during the day, drops off a bit about 5 pm and
then peaks at 6pm as everyone switches the tv on to watch the news over
a cup of tea. On a hot day the the load doesn't drop off but keeps
rising about 5 pm. I blame this on daylight saving, people leave a cool
air conditioned workplace and come home to a hot house and put their air
conditioners on flat out to cool the house down. If daylight saving was
an hour opposite you wouldn't be coming home at the hottest time of the
day. It's a way of passing cooling costs onto the worker.
Elmo
I work at a power station, and on our internal internet system we have a
load graph. We can bring up load data going back several years. It's
only updated every ten minutes. I haven't looked at the frequency
recordings for ages but I'll have a look when I go back to work.
The load generally rises during the day, drops off a bit about 5 pm and
then peaks at 6pm as everyone switches the tv on to watch the news over
a cup of tea. On a hot day the the load doesn't drop off but keeps
rising about 5 pm. I blame this on daylight saving, people leave a cool
air conditioned workplace and come home to a hot house and put their air
conditioners on flat out to cool the house down. If daylight saving was
an hour opposite you wouldn't be coming home at the hottest time of the
day. It's a way of passing cooling costs onto the worker.
Elmo
P
Phil Allison
Guest
" Suzy "
** Well, fuck you - bitch face.
** It ain't true of the Australian AC supply system and its is as dumb as
dog shit to introduce such naive fallacies.
** Yawn - more dumb bitch abuse.
** FUCK OFF back to the moronic, narcissistic on line chat rooms you
normally infest !!
Where asinine, anonymous public masturbators put THEMSELVES at the
CENTRE of every topic.
Just like dumb TROLLS all do.
........ Phil
** Well, fuck you - bitch face.
** It ain't true of the Australian AC supply system and its is as dumb as
dog shit to introduce such naive fallacies.
** ( snip more of Suzy's asinine abuse)
** Yawn - more dumb bitch abuse.
** FUCK OFF back to the moronic, narcissistic on line chat rooms you
normally infest !!
Where asinine, anonymous public masturbators put THEMSELVES at the
CENTRE of every topic.
Just like dumb TROLLS all do.
........ Phil
M
Michael A. Terrell
Guest
Phil Allison wrote:
Poor, poor, Phyllis! Always being abused by the big bad bullies! No
one would pick on her like that, if only she was a man!
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
Poor, poor, Phyllis! Always being abused by the big bad bullies! No
one would pick on her like that, if only she was a man!
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
E
Elmo
Guest
Suzy wrote:
Since you're mainly looking at frequency shifts of a faily short
duration a phase locked loop should be able to give you an indication of
the frequency shift if you have it heavily damped.
Elmo
Hey Suzy what about using a phase locked loop?
Since you're mainly looking at frequency shifts of a faily short
duration a phase locked loop should be able to give you an indication of
the frequency shift if you have it heavily damped.
Elmo
D
David L. Jones
Guest
On Feb 25, 11:05 am, "Phil Allison" <philalli...@tpg.com.au> wrote:
The web interfaced frequency meter is neat though, although it's not
even calibrated:
"We have not yet callibrated the meter, so the number you can see may
differ slightly from the real grid frequency by a constant small
amount.
The reason why we show so many decimal places in the frequency is to
ensure you can see it change. The changes (the movements of the
needle) should be quite accurate.
There will be a slight delay in the signal because it takes at least
two seconds to send the data over the internet.
Disclaimer: Please don't rely on our grid meter for any industrial or
other applications. We can't guarantee accuracy or reliability!"
Dave.
I agree with Phil on this one, the idea is lunacy.
The web interfaced frequency meter is neat though, although it's not
even calibrated:
"We have not yet callibrated the meter, so the number you can see may
differ slightly from the real grid frequency by a constant small
amount.
The reason why we show so many decimal places in the frequency is to
ensure you can see it change. The changes (the movements of the
needle) should be quite accurate.
There will be a slight delay in the signal because it takes at least
two seconds to send the data over the internet.
Disclaimer: Please don't rely on our grid meter for any industrial or
other applications. We can't guarantee accuracy or reliability!"
Dave.
D
David L. Jones
Guest
On Feb 25, 12:18 pm, Elmo <e...@sesame.com> wrote:
I any case I do hope she has a good plan to properly filter and
average out noise and other fluctuations from her "measurements".
Dave.
But still hasn't told us *why*.
I any case I do hope she has a good plan to properly filter and
average out noise and other fluctuations from her "measurements".
Dave.
T
Terryc
Guest
Elmo wrote:
My 2c is that I escaped a number of outages this summer as the heat
didn't happen. So I am wondering if we are going to cop them next summer
(if the heat comes back)?
Any info on how NSW is going for summer capacity?
My 2c is that I escaped a number of outages this summer as the heat
didn't happen. So I am wondering if we are going to cop them next summer
(if the heat comes back)?
R
RMD
Guest
On Sun, 24 Feb 2008 15:39:36 +1100, "Suzy" <not@valid> wrote:
years ago.
All I can say is you will need a very accurate measuring kit.
While I can't remember what the accuracy of the xtal we used was, I do
remember we could measure _no_ variation from 50Hz at any time. the
result was a big surprise to us at the time, I do remember that.
By and large the 50Hz mains could be used as a frequency standard in
it's own right, both short and long term.
I really doubt that total load affects frequency in any meaningful way
as you apparently believe from your website.
But measure away, who am I to stop a seeker of knowledge!
Ross
I remember trying to measure variations in mains frequency 30 odd
years ago.
All I can say is you will need a very accurate measuring kit.
While I can't remember what the accuracy of the xtal we used was, I do
remember we could measure _no_ variation from 50Hz at any time. the
result was a big surprise to us at the time, I do remember that.
By and large the 50Hz mains could be used as a frequency standard in
it's own right, both short and long term.
I really doubt that total load affects frequency in any meaningful way
as you apparently believe from your website.
But measure away, who am I to stop a seeker of knowledge!
Ross
P
Phil Allison
Guest
"RMD"
** Can be done very easily - if you have a stable sine generator with fine
tune and a basic CRO and frequency counter.
Just set up a lissajous pattern, with a ratio of 20 to 1, on the CRO
creen - then tweak the audio gen frequency to get the pattern stationary.
Read the generator frequency off the counter.
When it is 1000 Hz, the AC supply is 50 Hz.
When it is 1005Hz, the AC supply is 50.25 Hz.
** Ditto.
Bout as useful as reading tea leaves.
However, an AC voltmeter will tell you if the load in your local area is
unusually heavy or light at some given time.
....... Phil
** Can be done very easily - if you have a stable sine generator with fine
tune and a basic CRO and frequency counter.
Just set up a lissajous pattern, with a ratio of 20 to 1, on the CRO
creen - then tweak the audio gen frequency to get the pattern stationary.
Read the generator frequency off the counter.
When it is 1000 Hz, the AC supply is 50 Hz.
When it is 1005Hz, the AC supply is 50.25 Hz.
** Ditto.
Bout as useful as reading tea leaves.
However, an AC voltmeter will tell you if the load in your local area is
unusually heavy or light at some given time.
....... Phil
S
Suzy
Guest
"Elmo" <elmo@sesame.com> wrote in message news:47c21a94
person PA!
Great! I'll take much more notice of your replies than that strange strange
person PA!
S
Suzy
Guest
"Elmo" <elmo@sesame.com> wrote in message
news:47c217a5$1_5@news.peopletelecom.com.au...
calibrating. That was the reason for my original post about dividing down
from crystal oscillators of eg 2 MHz
news:47c217a5$1_5@news.peopletelecom.com.au...
Yes, but I'm interested in going one better than the website, and actually
calibrating. That was the reason for my original post about dividing down
from crystal oscillators of eg 2 MHz