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Feeding solar power back into municipal grid: Issues andfinger-pointing

M

Mho

Jan 1, 1970
0
You need to change your
"fixed spacing" font to one that is "fixed spacing"

I can even read it perfectly in your reply.

------------------

"David Nebenzahl" wrote in message


Sorry, it's still a hopeless hash.

I really do want to follow your example, but I can't until I can see
your circuit diagram properly. This ASCII-art thing clearly isn't
working; any chance you can post a picture somewhere? Then I'll be able
to follow along.


--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)
 
D

David Nebenzahl

Jan 1, 1970
0
You need to change your "fixed spacing" font to one that is "fixed
spacing"

I can even read it perfectly in your reply.

Look, my display font IS monospaced. Like, duh.

It's still all garbled. Line wrapping and all that. Your news client
(Microsoft Windows Live Mail 15.4.3508.1109) probably behaves
differently from mine (Thunderbird).


--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)
 
D

daestrom

Jan 1, 1970
0
Why would there be a local increase in the voltage?

The grid is filled with tapchangers and capacitors to adjust the voltage
to a constant level, loads on a complex grid can shift load continuously
to another place. A small PV source may increase the voltage up to the
next house and would never be noticed.

Like he said, if there is a change in the current flow there is a change
in the voltage drop across each component between you and 'the grid'.
The impedance of these components is small, but nevertheless it exists.

Besides, grid voltage regulation is not perfect. Those tap-changers you
mentioned have discrete steps and most have time-delays in them with a
dead-band around their set-point. These are designed so the thing
doesn't wear out constantly stepping up and down when the voltage
set-point is 'between' the tap settings.

daestrom
<snip>
 
Google "Norton and Thevinin Equivalency" or "Norton Thevinin
Circuits".

You'll see that a resistive circuit can be modeled as either a current
source or a voltage source together with a resistor and that they are
interchangeable and equivalent in how they behave.

Bingo! It doesn't matter which you model the inverter as, the physics doesn't
change.
 
N

no spam

Jan 1, 1970
0
Jim Wilkins said:
Would the contacts be the tungsten (heavy) cylindrical slugs sometimes
found below equipment-laden power poles?

jsw

... twould be a strange grid/retic system indeed were
tap change contacts found in the environment.
Then again I am not surprised at anything uttered
from those who feed the Gymmy Bob troll.

GB will be very busy searching his digests of
"Popular Mechanics" for the term "dead-band"
just to be sure it isn't an old Bob Marley joke:->

"Gymy Bob" <[email protected]>/http://preview.tinyurl.com/3auj4kc
"John P. Bengi" <[email protected]>/http://preview.tinyurl.com/3zgxjxa
"Solar Flare" <[email protected]>/http://preview.tinyurl.com/42ytgkq
"Pizzza Girl" <[email protected]>/http://preview.tinyurl.com/3p979nm
"Janice" <[email protected]>/http://preview.tinyurl.com/3bctgwr
"Joesepi" <[email protected]>/http://preview.tinyurl.com/3qkwmxr

... mind how you go. Don't want you
bleeding all over the place:-D
 
D

daestrom

Jan 1, 1970
0
Would the contacts be the tungsten (heavy) cylindrical slugs sometimes
found below equipment-laden power poles?

jsw

The few tap-changers I've seen 'up close and personnel' are in
sub-stations, not pole-mounted. The contacts are in oil-bath and
arranged such that they don't open under appreciable current (multiple
contacts, a center-tapped inductor and ingenious mechanism).

daestrom
 
M

Mho

Jan 1, 1970
0
Similar experiences here.The contacts are usually just copper or copper
plated with silver.

Many schemes are contrived to save the wear and tear on the contacts. On
larger capacity units there are two sets of contacts, ones that take the arc
and are easy to replace and a second set that can carry big currents, close
last and open first.

Some use vacuum bottled contacts to eliminate arcing and most use an
inductor or resistance not as good) to afford tap changing without ever
breaking the circuit.

Oh, I have dealt with a few pole mounted units for inline use in the rural
long lines to boost it back up a bit.
--------------

"daestrom" wrote in message The few tap-changers I've seen 'up close and personnel' are in
sub-stations, not pole-mounted. The contacts are in oil-bath and
arranged such that they don't open under appreciable current (multiple
contacts, a center-tapped inductor and ingenious mechanism).
 
N

no spam

Jan 1, 1970
0
one rattling tosser wrote from said:
[ghost-0-busted]
Now you are getting the picture.
Maybe you are not quite the dumb-ass
I first read. That _is_ "ass" not "arse".

.. mind how you go.

mind your manners spam-sickle, or leave the virtual classroom !

PATECUM

/YOU\

.... mind your tone of voice, chum.
I might just be one of those Usenet
"tough guys" you dream you
could maybe be, one day.

for now..?

GFYB
 
N

no spam

Jan 1, 1970
0
[fxd the fucking mess WLM made of the sub-thread]
"daestrom" wrote in message

The few tap-changers I've seen 'up close and personnel' are in
sub-stations, not pole-mounted. The contacts are in oil-bath and
arranged such that they don't open under appreciable current (multiple
contacts, a center-tapped inductor and ingenious mechanism).

daestrom
OCB, my friend. Another thing altogether.
Sorry dude.. someone should have explained to you what
you were observing.

fwiw..?
You have been around a loooong time, friend, and often are
fairly accurate in your posts. Is it too much to ask to quit trying to
offset the GB spiel when it is clear you have NFI what HE is
talking about???
GB will spend hours (if necessary) combing old posts to
come up with something both topical AND stupid.. just to
lead guys like you by the nose.. m'kay?
Leave it be.. IF he gets too far off the track with sucking in
a moron --->Jim Wilkins <[email protected]><----
_someone_ who does know will correct the information.
That option has always worked so far....

jes sayin' like...
Similar experiences here.The contacts are usually just copper or copper
plated with silver.

Many schemes are contrived to save the wear and tear on the contacts. On
larger capacity units there are two sets of contacts, ones that take the arc
and are easy to replace and a second set that can carry big currents, close
last and open first.

Some use vacuum bottled contacts to eliminate arcing and most use an
inductor or resistance not as good) to afford tap changing without ever
breaking the circuit.

Oh, I have dealt with a few pole mounted units for inline use in the rural
long lines to boost it back up a bit.

PM let you down, Gymmy Bob//dipshit, despite the hours
you have spent searching publications, yo poe clooless
loser!
Not helped by the fact you have no basis on just what
it is you need to find.
"daestrom" is describing OCBs, you felt that a challenge
and a clue?
The poor interpretation of what you read in PM is best
described as a typical ABS design, either pole mounted
or (vacuum assisted) within high frequency switching circuits
as found in transmitters (switchrooms).
You could have easily came up with a more believable line
of Bullshit (and thereby denied myself this post) were you
to have done a Webot search to find the relevant design
scenarios.
But you have NEVER been near anything like this equipment.
No authority on the planet would let YOU anywhere near a
HV switchyard! Your ARE a fucking lunatic!

Tap change design is built as a 'sliding' mechanism and as the
link says, complex in design allowing for many variables in
load change on the tranny as the assumption of lower or higher
currents is introduced to the winding.
http://electrical-science.blogspot.com/2010/04/transformer-tap-changer.html.

The only 'clappers' (silver clad or no) in your head are not
an ABS being operated, unfortunately... switching You off is
akin to shoveling shit uphill~!!

get digging, arsehole. I want to see you sweat this thread!
-------------->LMA0@ewe
 
D

daestrom

Jan 1, 1970
0
[fxd the fucking mess WLM made of the sub-thread]
"daestrom" wrote in message

The few tap-changers I've seen 'up close and personnel' are in
sub-stations, not pole-mounted. The contacts are in oil-bath and
arranged such that they don't open under appreciable current (multiple
contacts, a center-tapped inductor and ingenious mechanism).

daestrom
OCB, my friend. Another thing altogether.
Sorry dude.. someone should have explained to you what
you were observing.

Nonsense. I know an Oil Circuit Breaker and an LTC (Load Tap CHanger)
and I can certainly can tell them apart. Maybe you don't recognize my
description of an LTC because you've never seen one?

You're no 'friend' of mine, and I don't care for your advice. The other
poster brought up the question about tungsten contacts in a tap changer
on a pole. I merely replied with my experience of load-tap changers.

As for being around too long, you need to get out more. I've seen
brand-new multi-MVA LTC's that use reactance switching installed as
recently as last year. The controls are no longer agastats and
voltage-sensitive relays, that's been replaced with solid-state/digital.
But the power circuit, including the winding taps, and all, are still
the same.

'Mho' is right to point out that the 'contacts' are sometimes really two
separate ones, an arcing set and a steady-state load-carrying one.
Although the ones I've seen had a silver-plate.

Just because the whole LTC is immersed in oil, doesn't make it an OCB.
fwiw..?
You have been around a loooong time, friend, and often are
fairly accurate in your posts. Is it too much to ask to quit trying to
offset the GB spiel when it is clear you have NFI what HE is
talking about???
GB will spend hours (if necessary) combing old posts to
come up with something both topical AND stupid.. just to
lead guys like you by the nose.. m'kay?
Leave it be.. IF he gets too far off the track with sucking in
a moron --->Jim Wilkins<[email protected]><----
_someone_ who does know will correct the information.
That option has always worked so far....

jes sayin' like...


PM let you down, Gymmy Bob//dipshit, despite the hours
you have spent searching publications, yo poe clooless
loser!
Not helped by the fact you have no basis on just what
it is you need to find.
"daestrom" is describing OCBs, you felt that a challenge
and a clue?

No, again I'll ask you to not speak for me. I'm describing load-tap
changers, not OCB's. If you don't know what multi-MVA load-tap changers
are or never seen one, kindly STFU. The design of them is simple, stood
the test of many years and still used today.

The mechanism and windings *are* submerged in the oil of the transformer
tank, but that doesn't make them OCB's. The oil is used to cool the
windings just like all MVA sized transformers.
Tap change design is built as a 'sliding' mechanism and as the
link says, complex in design allowing for many variables in
load change on the tranny as the assumption of lower or higher
currents is introduced to the winding.
http://electrical-science.blogspot.com/2010/04/transformer-tap-changer.html.

The only 'clappers' (silver clad or no) in your head are not
an ABS being operated, unfortunately... switching You off is
akin to shoveling shit uphill~!!

Guess again. No-load tap changers often use a screw and clamp
mechanism. But as the name implies, they cannot change position while
loaded. The system has no provisions for interrupting even normal load
current.

Load-tap changers are a different design that avoids having to
disconnect the load while changing taps. As your own reference states,
'Some form of impedance is used to prevent short-circuiting of the
tapped sections'. A simple 'slider' of the make-before-break' design
would not work. As soon as the slider shorted across a tap section,
large currents would through across the slider (even a 2% step will
generate huge currents when directly shorted by such a slider). Then
the trailing edge of your 'slider' would have to interrupt that current,
lots of arcing, thing wouldn't last very long.

One common way to solve this is a center tapped inductor. Each end is
connected to a contact that can move from tap to tap, the center tap is
where the load current is taken from. So the load current splits in the
two halves of the inductor, and the effect of the inductance is
completely canceled out. But when one contact is on a different tap
from the other, the end-to-end inductance limits the short circuit
current of the two adjacent taps. This type can step with very large
load currents and some are even rated for 'half-step' operation,
providing finer voltage adjustments without the cost of more individual
taps.

Another method is to use a second circuit with a resistance that
connects to a tap. Then the main load carrying contacts can open with
the current flowing through it interrupted easily. Then the main load
contact moves to a new tap, and the auxilary/diverter-switch contact
reopens. The diverter-switch contact can't be kept closed too long
because the resistor is carrying full load current and will rapidly heat
up.(hence this type has to 'step' much faster to avoid this)

daestrom
P.S. Your link doesn't mention 'slider' contacts anywhere. Proof you
just made that up??

P.P.S. Rather childish to modify the headers with followup to
'alt.clueless'. Is this your way of winning arguments, tricking people
into replying to other news groups?

You're not worth any more of my time...<plonk>
 
M

Mho

Jan 1, 1970
0
daestrom has a bad day.
You mostly come across as well researched and knowledgeable. From my end I
can tell you are experienced in the field in question and have suspicions we
have crossed paths in real life.

However....

I am surprised you got caught up in that troll. This is not your usual M.O.

This moron changes his nickname almost every post, uses multiple NNTPs and
news browsers to conceal his mental illness that becomes very apparent, very
quickly, to most. He does a little research for the subject at hand in many,
many groups in order to "blend in" with the crowd only to attempt to lead
the sheeple into black-balling a particular person. This technique has
brought many groups to it's knees and made them dormant over many years. We
suspect some past hurt feelings with Usenet in general or a commercial
venture to destroy the Usenet following.

I offer an example of a ghost town group sample:
http://groups.google.ca/groups/sear...nitus&as_usubject=&as_uauthors=Bluto&safe=off

This has been going on since year 2000 with this jerk. He thinks everyone is
the same person.

My apologies for any mental interference this dipshit has caused you or the
group.
 
N

no spam

Jan 1, 1970
0
[..]
Sir,
(at the time of writing)
Are you aware April 26 is WIPD?
http://en.wikipedia.org/wiki/World_Intellectual_Property_Day

I am claiming the right of redress under IP 'rules'
So.
Let us deal with the Usenet portion of your post, first.
The rest is now superfluous to the thread... as
the fools humping your post ably demonstrate.
Message-ID: <[email protected]>
Message-ID: said:
P.P.S. Rather childish to modify the headers with followup to
'alt.clueless'. Is this your way of winning arguments, tricking people
into replying to other news groups?
Why ask? The method certainly works well for the fools among
us. Just go check <a.c> for the presence "Mho"/"Josepi" under
the past 'disguises'.
(eet) represents (eet)self most ably.
http://preview.tinyurl.com/3uubwo8
http://groups.google.com/groups/sea..._usubject=&as_uauthors=John+P.+Bengi&safe=off
http://preview.tinyurl.com/3vcx8e6
http://groups.google.com/groups/sea...ess&as_usubject=&as_uauthors=Gym+Bob&safe=off

Those links address either 'end' of a huge spectrum of stupidity
GB has proven (eet) is well deserved of in recognition.

That said, I have never really cared for the attitude displayed
by you "Big Apple" folk, neither.
Loud mouthed postulating mob of jerks.. in my humble opinion.
So it is, I, rarely (if ever) even acknowledge the presence with
anything more than a nod or a wink in a post. Such was the
spirit allowed in my earlier comment.
'alt.clueless'.
Where you find yourself in such a predicament you could
consider using nntp software that allows a full view of a
post, and the response _you_ generate.

http://mirrors.easynews.com/agent/ftp.forteinc.com/pub/agent/english/

Glorified web browsers may just serve you text jocks just
far as is needed to make _you_ feel good. Do not make
it _my_ problem they land you deeply in shit when you are
busy fucking with posts you do not understand.

As said... jes sayin' like.

You're not worth any more of my time...<plonk>
Just who do you think you are fooling?
And do please quantify just where have I sought or
expected _any_ of your time?
My post was in response to GB shite posted, naught
to do with _you_.
You get some of mine (time - now) as you are posting
in spectacular simulation of an aggrandizing git!
That, after simply reading a heads up in the
sub-thread!

Parasite... you understand (eet) when put that simply?
GB takes a host, sucks it dry, drops off and
attaches to the next passing fat bus.
There is how GB has managed to bring down a
score of newsgroups.
Playing the self appointed "x-spurts" in a group off
against each other. Need I say "USAnians" are his
favorite "host" as you guys are so far up ya-self
you just do not know when the GB bug is hooked
into your femoral artery watching you wank yourself
stoopid!

You may well know GB in another of his modes.
Same MO.. different dress.
You (daestrom) certainly know the edjut:
http://al.howardknight.net/msgid.cgi?STYPE=msgid&MSGI=<[email protected]>
AND...
as "Solar Flare"
http://groups.google.com/groups/pro...AACceBADITErDr7_oJBN-CH8rhlH0Pnl47z4AZhN98BFg

... there exists many like examples.

For the rest???
Read it if you must :-/

/sets clock

--

[fxd the fucking mess WLM made of the sub-thread]
"daestrom" wrote in message On 4/19/2011 17:28 PM, Jim Wilkins wrote:
...Those tap-changers you
mentioned have discrete steps and most have time-delays in them with a
dead-band around their set-point. These are designed so the thing
doesn't wear out constantly stepping up and down when the voltage
set-point is 'between' the tap settings.

daestrom
<snip>

Would the contacts be the tungsten (heavy) cylindrical slugs sometimes
found below equipment-laden power poles?

jsw

The few tap-changers I've seen 'up close and personnel' are in
sub-stations, not pole-mounted. The contacts are in oil-bath and
arranged such that they don't open under appreciable current (multiple
contacts, a center-tapped inductor and ingenious mechanism).

daestrom
OCB, my friend. Another thing altogether.
Sorry dude.. someone should have explained to you what
you were observing.

Nonsense. I know an Oil Circuit Breaker and an LTC (Load Tap CHanger)
and I can certainly can tell them apart. Maybe you don't recognize my
description of an LTC because you've never seen one?

You're no 'friend' of mine, and I don't care for your advice. The other
poster brought up the question about tungsten contacts in a tap changer
on a pole. I merely replied with my experience of load-tap changers.

As for being around too long, you need to get out more.
Another of the problems you guys suffer, poor comprehension.
I _said_ "You have been around a loooong time".

/drawl
Go think about the differences of context, pilgrim.
/end drawl

[apols to the Duke]
I've seen brand-new multi-MVA LTC's that use reactance switching installed as
recently as last year. The controls are no longer agastats and
voltage-sensitive relays, that's been replaced with solid-state/digital.
But the power circuit, including the winding taps, and all, are still
the same.

'Mho' is right to point out that the 'contacts' are sometimes really two
separate ones, an arcing set and a steady-state load-carrying one.
Although the ones I've seen had a silver-plate.

Just because the whole LTC is immersed in oil, doesn't make it an OCB.


No, again I'll ask you to not speak for me. I'm describing load-tap
changers, not OCB's.
So it seems, as you say, now.
In my read of your verbosity you ring bells to demonstrate your
ignorance in not identifying with someone who knows more than
enough to test what you do actually know. Posting pompous
buffoonery to create some form of "I am the expert here"
communication (as you have done in your 'implosion') is wasted
effort in these "home-moaner" type newsgroups. Nobody is interested
beyond "cheap", without that word in your post the eyes just glaze
over. If you want direction to newsgroups where professionals
discuss such things, just ask.
If you don't know what multi-MVA load-tap changers
are or never seen one, kindly STFU. The design of them is simple, stood
the test of many years and still used today.
Well that's nice to know.
Given the length of your unsolicited response I was prompted
to read from the line (quantity) length a "new wheel" had been
installed, universally :p
Observing modern (post Y2000) switchyards
I do wonder just how the internals of those "from Mars"
structures would present with the covers off.
Tis somewhat comforting to know the basics remain
as invented, albeit described in somewhat flowery language
by those who stand in awe of it all being a "big deal".
HV is not, a "big deal", simply being fucking dangerous
when designed and/or maintained by the likes of those
posting to this thread!
Fortunately "Regulation" keeps the deadheads out of the
professional workplace.

The mechanism and windings *are* submerged in the oil of the transformer
tank, but that doesn't make them OCB's. The oil is used to cool the
windings just like all MVA sized transformers.
oH indeed.
How generous of you in saying :-~
Dare I say "PCB free"??

Feeling a need to make statement about such a basic
attribute of HV switchyard apparatus says you aren't so sure
of your topic. Be very sure I am, and IF you are currently employed
in the industry then I can say "long before your time my role was
principally overseeing contracted maintenance"... for the *owner*
of the equipment. You are familiar with maintenance requirements?
http://www.esigroup.net/
Can you say "Torr" ??? :)
Guess again.
You challenge me, claiming I speak for you - which I was not - and
yet here you are speaking for GB... tut tut, my dear fellow.. tut tut
No-load tap changers often use a screw and clamp
mechanism. But as the name implies, they cannot change position while
loaded. The system has no provisions for interrupting even normal load
current.

Load-tap changers are a different design that avoids having to
disconnect the load while changing taps. As your own reference states,
'Some form of impedance is used to prevent short-circuiting of the
tapped sections'. A simple 'slider' of the make-before-break' design
would not work. As soon as the slider shorted across a tap section,
large currents would through across the slider (even a 2% step will
generate huge currents when directly shorted by such a slider). Then
the trailing edge of your 'slider' would have to interrupt that current,
lots of arcing, thing wouldn't last very long.
Again the problem of "speaking amongst plebs" is apparent.
"Sliding mechanism" is engineering 'speak' for a transitional change
of state. In contrast (if you like) to the peaks and troughs of elements
of any generated sinusoidal wave, single or polyphase.
Your reading telling you it is *my* description of the physical
operation of a TC says more about you than it does anything I could
print.
One common way to solve this is a center tapped inductor. Each end is
connected to a contact that can move from tap to tap, the center tap is
where the load current is taken from. So the load current splits in the
two halves of the inductor, and the effect of the inductance is
completely canceled out. But when one contact is on a different tap
from the other, the end-to-end inductance limits the short circuit
current of the two adjacent taps. This type can step with very large
load currents and some are even rated for 'half-step' operation,
providing finer voltage adjustments without the cost of more individual
taps.

Another method is to use a second circuit with a resistance that
connects to a tap. Then the main load carrying contacts can open with
the current flowing through it interrupted easily. Then the main load
contact moves to a new tap, and the auxilary/diverter-switch contact
reopens. The diverter-switch contact can't be kept closed too long
because the resistor is carrying full load current and will rapidly heat
up.(hence this type has to 'step' much faster to avoid this)
Best you go write yourself a tech sheet and mount it on a website said:
daestrom
P.S. Your link doesn't mention 'slider' contacts anywhere. Proof you
just made that up??
Again the problem of "speaking amongst plebs" is apparent.
"Sliding mechanism" is engineering 'speak' for a transitional change
of state. In contrast (if you like) to the peaks and troughs of elements
of any generated sinusoidal wave, single or polyphase.
Your reading telling you it is *my* description of the physical
operation of a TC says more about you than it does anything I could
print.
 
M

Mho

Jan 1, 1970
0
Since you claim to have not dealt with poletop tapchangers, I thought you
may find this interesting.

These units are basically designed to correct system sags due to long lines
and therefore I thought of them as 1:1 style (in my own head). Typically
the ones I dealt with were 1:1 +/-20% IIRC

An option we never purchased was the two voltage sensing take-offs, one on
each side of the tapchanger. Primary and secondary sides, if you will.

This gets interesting and I am glad I did not have to do the metering calcs
for any bi-directional units while up on a pole in the rural. It can get
nasty out in a bare field trying to do trig calcs...LOL I know you
understand this part of country weather.

Our system, where we used these, were only normally capable of feeding only
one direction through the tapchange unit, so we didn't require two potential
metering spots. If the unit ever became backfed the sensing would see high
or low voltage and attempt to correct by tapchanging in the wrong direction,
causing a runaway to one end. The dual potential metering allowed the
circuit to sense directional power flow (ooops = energy) and change the
direction of tap correction so it would not run to the top or the bottom.
With rural cap banks on poles for PF correction the trig and setup gets real
hairy and I could not begin to re-create anything like that, anymore,
without losing some sleep. The cut-off angles for controlling sensing
direction are not at unity angles to allow for pf loads (ind. and cap.) and
still correct voltage in the right direction.

I know you would have loved it with your displayed analytical brain! It's an
engineering challenge with much field feedback and learning.

------------------------------

"daestrom" wrote in message <mass confusion attempted by others snipped>

daestrom
P.S. Your link doesn't mention 'slider' contacts anywhere. Proof you
just made that up??

P.P.S. Rather childish to modify the headers with followup to
'alt.clueless'. Is this your way of winning arguments, tricking people
into replying to other news groups?

You're not worth any more of my time...<plonk>
 
M

Mho

Jan 1, 1970
0
Do **** off and die. Lunatic scum LOL LOL

------------------------------

mass confusion attempted in message

Since you claim to have not dealt with poletop tapchangers, I thought you
may find this interesting.
 
M

Mho

Jan 1, 1970
0
AS YOU SAY, IGNORE IT, FOOL
LOL
LOL
LOL
Take your own advice, SLOB..
------------------------------

in message

Do **** off and die. Lunatic scum LOL LOL

------------------------------

mass confusion attempted in message
Since you claim to have not dealt with poletop tapchangers, I thought you
may find this interesting.

Take your own advice, SLOB..

PATECUM
TGITM
 
B

Bob F

Jan 1, 1970
0
David said:
Sorry, I don't think you know what you're talking about.

You seem to think that you can "force" or push "voltage" into a line,
by using a higher voltage than what's on the line.

That's not at all what's at work here when one has a photovoltaic
system and an intertie feeding power back into "the grid".

The intertie and the house's power connection are going to be at
pretty much exactly the same voltage. What happens is that the PV
system is connected *in parallel* with the grid; it's dumping more
*current* into the system, not more voltage.

You do understand the difference between current and voltage, don't
you?

"Pretty much the same" is not the same as "the same". The grid may have very low
impedence, so the voltage difference will not be much, but if the voltage you
produce is less than the grid voltage, no current will flow from you to the
grid. The higher your voltage is above the grid voltage (at your house), the
more current will flow into the grid. Kind of like charging a battery - until
you exceed the battery voltage, no current will flow. As the voltage exceeds the
battery voltage the current increases rapidly.
 
M

m II

Jan 1, 1970
0
Wikipedia is not a source of information (by their own definition). Do
not use it for quotes. Now your information is a fourth hand
paraphrasing, lower than a rumour level.

-------
"g" wrote in message
harry wrote:


I doubt that the regional sub-station is going to do that.

From Wikipedia:
"In an electric power distribution system, voltage regulators may be
installed at a substation or along distribution lines so that all
customers receive steady voltage independent of how much power is drawn
from the line."

Obviously when a local area is supplying power to the grid, power
generation elsewhere will be reduced. And any voltage changes that
results from that will be adjusted with line voltage regulators, if
necessary.


I'm saying that a small-scale PV system is going to raise the local
grid
voltage for the homes connected to the same step-down distribution
transformer.All the linear loads on the local grid will consume the
extra power (probably about 250 to 500 watts per home, including the
house with the PV system on the roof). The extra 250 to 500 watts
will
be divided up between the various AC motors (AC and fridge
compressors,
vent fans) and lights. They don't need the extra volt or two rise on
their power line supply - the motors won't turn any faster and the
lights will just convert those extra watts into heat more than light
output.

How do you get the value 250-500W?

Motors will only increase their energy drain by raising the frequency,
Plus a small loss due to internal resistance in the windings.

As for a resistive load, increasing the voltage from 120 to 125 volt
will result in a power drain increase of about 8.5% or 8.5 W for a 100W
light bulb, assuming 120V is the nominal voltage.

Remember though that the voltage increase on the step-down side of the
transformer due to homeowners PV arrays will be less than 5 volt pretty
much guaranteed. Local codes state a maximum voltage drop (7V in BC)
over the lines to a house, at 80% load of service panel capacity.

Most households have a 200A service panel. A 10kW PV array is well
below
the service panel capacity.

And you cannot just look at the PV array output. You must take into
account the local energy consumers as well. That will reduce the
current
going into the grid, and thus the voltage increase.
The home owner with the PV system will get paid 80 cents / kwh for
the
40-odd amps he's pushing out into the grid, but that energy will be
wasted as it's converted disproportionately into heat - not useful
work
- by the linear loads on the local grid.

You claims are pretty vague, please explain what you mean by wasted.

By the way, there is some "waste" by just using the grid only as well.
Losses everywhere in the grid.
I'm claiming that there won't be a corresponding voltage
down-regulation
at the level of the neighborhood distribution transformer to make the
effort worth while for all stake holders.

What is your definition of worth while? And what do you know about the
utility's voltage regulation policies?

The utilities _have_ to use voltage regulation due to demand changes.
 
M

m II

Jan 1, 1970
0
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



m II did NOT write:
Wikipedia...

Stop forging my user name, Maynard, Mho, Gimmy Boob, etc.etc... I see
you accidentally left your home phone number and address in another
counterfeit post. Care to see it published? Keep up the postings.

Grow up, Maynard


mike




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M

Mho

Jan 1, 1970
0
Go for it trollboi!
Then get off the Internet. Children are afraid.

You'll always be a POS troll. Only two more years to go to catch up with
your garbage.

How do you like me now?

-------

"m II" wrote in message
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



m II did NOT write:
Wikipedia...

Stop forging my user name, Maynard, Mho, Gimmy Boob, etc.etc... I see
you accidentally left your home phone number and address in another
counterfeit post. Care to see it published? Keep up the postings.

Grow up, Maynard


mike




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Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

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