Diodes and bypass diodes
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Hello, sorry if I change a bit the topic of the post or ask somewhat out of place. But my question or ask is for Mike90250 and longwolf, I saw your posts and I really like your figures that they uses for show diode bypass.
Mike90250 :
longwolf:
In special longwolf, I'm student and I'm newbie in this topic, but I want to understand very well and try to use in my home some things...
Well, my question or ask is about the Software that they use for make figures?, in special the use longwolf... What software they use for it?
Thanks a lot.Leave a comment:
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Diodes
Designing an array of 18volt, 4 Amp, 172 Watt solar panels and need to decide what bypass diodes and blocking diode to use...Leave a comment:
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Bypass diodes are usually Schottky diodes, with sufficient power rating (and heat sink) to only have about .5V drop across them. At the MOST, I would go no more than 18 cells without a diode.Leave a comment:
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Bypass Diode Function
voltage to force their current through a shaded or defective cell. The overheating
would be at the non functional cell?
Putting a bypass diode on each cell, would apply about 1V (diode drop) reverse
voltage on a non producing cell. That seems to be accepted as OK for shade,
don't know for a cracked cell.
I don't see anyone putting a bypass diode on every cell. Short of that, the voltage
applied to a non functioning cell will that of the other cells being bypassed by the
diode, plus about a volt drop in the diode from overall array (bypass) current. So
my question would be, how many cells (or how much voltage) can one diode
safely bypass?
There will be no panels on roofs here, in the country. But for now there are some
convenient spots to put them. In one spot I see 200 to 800 W (clouds or sunny) till
early afternoon, when the sun moves behind a grove of trees. At that point I am
willing to have another similar array come out of the shade for the rest of the day.
I am willing to duplicate those resources for the locations.
To put up panels never shaded by all the trees, I would have to go 1/8 mile away
from the house. That would happen if expanded to the 10 KW level. But first I
would need a power handling system able to cover that distance with good
efficiency, have a few ideas on that. Bruce RoeLeave a comment:
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You really should have bypass diodes, and you should re-site panels to avoid shade
With no diode, any shade, anywhere on the array , will cut output way down, and the shaded panel will tend to overheatLeave a comment:
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Bypass Diode Function
As I understand it, these diodes are only used to preserve some power output,
when part of a panel is shaded. This would be esp important with several
series connected panels. So protecting the panel from destruction is not part
of the function?
In my case, I expect to lose a whole panel at a time (tree shadow blocks a
panel at certain times of day). And I won't have panels connected in series,
I prefer to operate around 30 VDC. So I really don't need bypass diodes?
As for parallel connections, even a shaded panel generates pretty much
full open circuit voltage. So if connected in parallel with another panel
not shaded, I would not expect any reverse current in the shaded panel,
as long as its open circuit voltage at least equals a loaded panel voltage.
So no series diodes for each parallel panel are needed either? Bruce RoeLeave a comment:
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You are pissing into the breeze - hope it does not get too damp! Please don't call it 'playing the devil's advocate' - you are simply breaking the rules which you have been made aware of and know the basics at least.
Fighting city hall? Again I would not call tilting windmills fighting city hall - hope you have you own Pancho Sanchez (think that was his name) to pick you up and put you back on your mule when you collide with the system.
Individual components of the system must be approved by UL or an equivalent agency.
The UL didn't come inspect individual computers either - representative samples are tested and approved.
No problem, you can certainly do it but don't whine when everything goes down the toilet sometime in the future.
RussLeave a comment:
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Well I'm playing devil's advocate and "fighting city hall" at the same time, but if I pay a solar installation company to install an entire system for me, that system is not UL certified. Nobody from the Underwriter's Laboratories comes to my house to certify it.
So I still may contend that the inverter is U.L. certified and therefore I can connect that to the grid.Leave a comment:
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Wrong - the system is connected to the grid.
RussLeave a comment:
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So technically, only my inverter is hooked to the grid, yes? (I like the enphase micro-inverters for going to the grid). My panel is hooked to the inverter. The inverter, which is UL-approved, is connected to the grid.Leave a comment:
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Generally, and always in the USA with the National Electric Code, only UL components can be connected to a house wiring. A panel to charge a camping battery, or a electric bike is fine for homebrew. Learning by doing is the best way, as you are finding out.
Enjoy.Leave a comment:
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