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

Discussion in 'Home Power and Microgeneration' started by Home Guy, Apr 4, 2011.

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  1. Mho

    Mho Guest

    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*?)
     
  2. 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*?)
     
  3. daestrom

    daestrom Guest

    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>
     
  4. Guest

    Bingo! It doesn't matter which you model the inverter as, the physics doesn't
    change.
     
  5. no spam

    no spam Guest

    ... 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" <>/http://preview.tinyurl.com/3auj4kc
    "John P. Bengi" <>/http://preview.tinyurl.com/3zgxjxa
    "Solar Flare" <>/http://preview.tinyurl.com/42ytgkq
    "Pizzza Girl" <>/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
     
  6. daestrom

    daestrom Guest

    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
     
  7. Mho

    Mho Guest

    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).
     
  8. no spam

    no spam Guest

    /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
     
  9. no spam

    no spam Guest

    [fxd the fucking mess WLM made of the sub-thread]
    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 <><----
    _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?
    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!
    -------------->[email protected]
     
  10. daestrom

    daestrom Guest

    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.
    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.
    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>
     
  11. Mho

    Mho Guest

    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.
     
  12. no spam

    no spam Guest

    [..]
    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: <FnLsp.3989$>
    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.
    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.

    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=<fP1Ye.86014$>
    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

    --

    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]
    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.
    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.

    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" ??? :)
    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
    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.
    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.
     
  13. Mho

    Mho Guest

    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>
     
  14. Mho

    Mho Guest

    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.
     
  15. Mho

    Mho Guest

    AS YOU SAY, IGNORE IT, FOOL
    LOL
    LOL
    LOL
    Take your own advice, SLOB..
    ------------------------------

    in message

    Take your own advice, SLOB..

    PATECUM
    TGITM
     
  16. Bob F

    Bob F Guest

    "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.
     
  17. m II

    m II Guest

    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
    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.


    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.
    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.
    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.
     
  18. m II

    m II Guest

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1



    m II did NOT write:
    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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  19. Mho

    Mho Guest

    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:
    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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