# Feeding solar power back into municipal grid: Issues and finger-pointing - Page 23

Posted by Mho on April 19, 2011, 7:33 pm

You need to change your
"fixed spacing" font to one that is "fixed spacing"

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

"David Nebenzahl"  wrote in message

On 4/18/2011 7:02 PM trader4@optonline.net spake thus:

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

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Posted by David Nebenzahl on April 19, 2011, 8:12 pm

On 4/19/2011 12:33 PM Mho spake thus:

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).

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wassup
nuttin
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Posted by trader4@optonline.net on April 19, 2011, 11:31 pm
It shows up perfect when I look at it in David's replies too.
How about I just describe how to draw it on a piece of
paper which should be easy.  It's very similar to that
example circuit Wilkins provided a while back

Left side is the PV array voltage source V1, which we will vary.

Right hand side is fixed voltage source V2= 240volts,
representing the power company.

Now go across the top part of the circuit between V1 and V2
left to rightand draw a string of resistors connected in series
that connects the two.

In order.....

R1 is the internal resistance of the PV array
Rw is the resistance of the wire from the PV at the house to the grid
Rg is the resistance of the grid as it goes down the block to the load
Rg again is the resistance of the next piece of grid as it goes
another block
Rw is the resistance of the wire from the grid to the power company
source
R2 is the internal resistance of the power company source

For simplicity all these are 1 ohm each and per above connected look
like
this:

----R1-----Rw----Rg-----------Rg----Rw---R2----

Label the point between Rw and Rg on the left Vg.  This is the
connection
point measurement voltage at the grid, where the PV array wire from
the house attaches to the grid.

Connect the bottom of V1 to the bottom of V2

Add a load, Rload=100 ohms, one end connected between the two Rg
resistors at the
top and the other end connected to the bottom path between V1 and V2
that you drew in previous step

Here it is with the vertical connections left out:

---   R1  -- Rw ---Rg------Rg----Rw----R2----

________________________________________

Remember Vg is the voltage between Rw and Rg on
the left.

Now you have amodel of two power sources driving a load.
Follow the math I posted previously.

Posted by Bruce Richmond on April 18, 2011, 9:39 pm

http://www.solarpanelsplus.com/solar-inverters/How-Solar-Inverters-Work-Wit=
h-Solar-Panels.pdf

Posted by David Nebenzahl on April 18, 2011, 10:56 pm
On 4/18/2011 2:39 PM Bruce Richmond spake thus:

http://www.solarpanelsplus.com/solar-inverters/How-Solar-Inverters-Work-With-Solar-Panels.pdf

Y'know, that's the *second* time you've offered that document as a
supposed answer to a question, and it doesn't contain any more relevant
information to what I asked than it did the first time. It is chock-full
of other interesting details, but it does *not* answer my question at
all. The most they have to say is that a DSP is used to sense the
line-side voltage and relay it to the intertie; however, they don't
explain just how this all works in the detail I was asking for.

I invite you to point out specific sections that answer my question, as
I have a copy of the PDF handy, if you think I'm mistaken.

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wassup
nuttin
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k
where
here
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•
• Subject
• Author
• Date
 Re: Feeding solar power back into municipal grid: ... krw@att.bizzzzz... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... krw@att.bizzzzz... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... David Nebenzahl 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-19-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-18-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-15-2011
 Re: Feeding solar power back into municipal grid: ... Daniel who want... 04-14-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-14-2011
 Re: Feeding solar power back into municipal grid: ... trader4@optonli... 04-17-2011