Frequency standard

[Elmo]

"Suzy"
"Phil Allison"


** That web sites created by complete amateurs - greenie loopy ones too.

The supply frequency is not so simply related to demand as they naively
claim.

IOW - it's bollocks.


....... Phil

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

 

[Phil Allison]

"Suzy"
"Phil Allison"

But isn't it true, Phil, that more demand than supply will drag down
alternator shaft speed and thus frequency, and vice-versa?

** 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

 

[Elmo]

I meant "low" of course. BTW, that site looks quite good to me, and the
meter is natty.

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

 

[David L. Jones]

"Suzy"
"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

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.

 

[briang]

But isn't it true, Phil, that more demand than supply will drag down
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.

 

[Suzy]

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

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)?

 

[Elmo]

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.

For Suzys purposes it doesn't have to be calibrated, she's more
concerned with fluctuations and differentials than the actual frequency.

Elmo

 

[Phil Allison]

"Suzy" = not@valid

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)?

** ROTFL !!!

Better go learn about ohms law - honey ...




....... Phil

 

[Suzy]

"Suzy"
"Phil Allison"

** I will not answer dumb questions or engage in pointless chat.

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.

The folk behind that site have NO credibility and have given NO proof of
their claims.

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?

The idea put forward that individual appliances ought to dance to the tune
of tiny variations in the AC frequency is

UTTERLY LUNATIC !!!

Sound quite plausible to me. Wouldn't bother with a toaster though...

A typical f***** greenie idea.

Back to normal

Like banning incandescent bulbs and transformer plug packs.

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.

....... Phil

Suzy

 

[David L. Jones]

For Suzys purposes it doesn't have to be calibrated, she's more
concerned with fluctuations and differentials than the actual frequency.

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.

 

[Elmo]

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)?

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

 

[Phil Allison]

" Suzy "

"Phil Allison"

What a pompous answer!

** Well, **** you - bitch face.

It is true and is not "dumb" as you assert

** 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)

Sound quite plausible to me. Wouldn't bother with a toaster though...


Back to normal

** Yawn - more dumb bitch abuse.

I agree with you about that, but no doubt to you (o mighty one) it is
"pointless chat".

** **** 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

 

[Elmo]

I am needing to generate about 1v p-to-p at 50Hz sine wave as accurately as
I can. Please don't suggest syncing to mains as that's the application -- to
calibrate an instrument to measure the actual variance of the mains from
time to time from 50 Hz precisely.

My current (ouch) thoughts are to get a 2 MHz crystal and divide down to
50Hz. Any comments on this idea or an alternative?

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

 

[Terryc]

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.

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)?

 

[RMD]

I am needing to generate about 1v p-to-p at 50Hz sine wave as accurately as
I can. Please don't suggest syncing to mains as that's the application -- to
calibrate an instrument to measure the actual variance of the mains from
time to time from 50 Hz precisely.

My current (ouch) thoughts are to get a 2 MHz crystal and divide down to
50Hz. Any comments on this idea or an alternative?

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

 

[Phil Allison]

"RMD"

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.

** 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.

I really doubt that total load affects frequency in any meaningful way
as you apparently believe from your website.

** 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

 

[David L. Jones]

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.

Any cheap frequency meter with reciprocal measurement will be able to
measure it just fine.

Dave.

 

[Suzy]

... I work at a power station...

Great! I'll take much more notice of your replies than that strange strange
person PA!

 

[Suzy]

For Suzys purposes it doesn't have to be calibrated, she's more concerned
with fluctuations and differentials than the actual frequency.

Elmo

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

 

[Suzy]

" Suzy "


** Well, **** 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.




** **** 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

For once, I'll leave his vile foul mouth unedited. You have a problem
dealing with women, Phil, clearly. But, judging by previous posts you have a
problem dealing with men too! It's so easy for you to lose it, and I wasn't
even trying! My original post was in good faith, and I am interested in the
background theory and finding a solution, and as always prepared to learn.
Apparently, that can't be from you, because perhaps you have nothing
intelligent to provide. A knowledgeable protagonist demolishes the other
side's foolish argument (as mine well could be) with clear logical
offerings. The sexual connotations give a clue as to what your disorder is.
I believe there *is* a brain there, but maybe it is cloaked in a serious
inferiority complex...

There have been distinctively helpful occasions recently. but they quickly
(as now) degenerate into verbal flailing bout. Please have another go at
showing me why I was wrong in my suppositions. I'd be glad to admit it. And,
please tell all of us: what are your qualifications and experience to back
up your quick judgement of others? Come on, deep breath (no jokes about
thixteen...) and have a go. Respond to this ignoramus without bad language,
without diminishing, and achieve something. You could have a chance to add
to the body of human knowledge. I'm sure you can do it, Phil. Please have a
go. Why is it not the case than an imbalance of supply/load will lead to
variations in mains frequency. And by the way, even igoramuses (ignorami?)
are sometimes reasonably literate; that does not prove they are trolls. To
label anyone who dares to question you as a troll is a facile thing, quickly
seen through.