question

n-dee avatar image
n-dee asked

bigger mppt?

I've got an installation where east side has 6900 peak and it's not possible to add a second cable.

-> any insights if there will be a bigger mppt sometime? e.g. 250/115

regards,
Andy

MPPT Controllers
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Mike Dorsett avatar image Mike Dorsett commented ·
bigger mppt than what? Please can you describe your installation and problem in more detail?
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Trevor Bird avatar image
Trevor Bird answered ·

Hello @N-DEE …..I must confess the question is a little cryptic but have you considered paralleling two or more 250/100 MPPT units? Many can be paralleled to handle more power. They are networked so they share the load.

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nickdb avatar image nickdb ♦♦ commented ·
If he can't run more PV cabling, they can't share the panels, which is what I think he is asking for.
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rikhf avatar image rikhf commented ·
Do you mean divide 1 string over more MPPT's?
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nickdb avatar image nickdb ♦♦ rikhf commented ·
Yes. That can’t be done.

You can have multiple mppts each with their own pv array, coordinating charge.

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Trevor Bird avatar image Trevor Bird nickdb ♦♦ commented ·
That is interesting. I didn’t know that and cannot think of a reason to why multiple MPPT controllers cannot share a single solar array.
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nickdb avatar image nickdb ♦♦ Trevor Bird commented ·
There are many reasons, not the least comes down to how an mppt works. They will end up conflicting with each other. The networking is about coordinating shared charging not sharing PV.
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Trevor Bird avatar image Trevor Bird nickdb ♦♦ commented ·
Yes I understand the input impedance of each MPPT controller will vary to find the right impedance to match the maximum power transfer from the solar array. Given this happens dynamically during normal use both controllers will be changing the apparent characteristics of the solar array. If you were happy to accept the controllers will “hunt” at a rate determined by their mpp algorithm, wouldn’t that be better than not having full power available from the solar panels? I understand it is not ideal but the situation the OP finds himself in is not ideal.
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benm avatar image benm rikhf commented ·
you can not connect one string PV to two MPPT's
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johanndo avatar image johanndo benm commented ·

@rikhf @Trevor Bird You can, but it makes no sense, because they will individually track / search and kick each other around. MPPT controller are not like DCDC charger, they vary the load on the input to find the highest power point, they find one, canibalizing the power from the other, then the other starts a new search, kicking the first in the b... You get the point.

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n-dee avatar image
n-dee answered ·

Hi together,

Yes I know that we can't put two Trackers on one Solarcable.
Thats why I was asking if there might be a bigger one than the 250/100 in the future.

br,

Andy

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kevgermany avatar image kevgermany ♦♦ commented ·
There's already the Smart Solar MPPT RS, 450V, 100 and 200A models.
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n-dee avatar image n-dee kevgermany ♦♦ commented ·
Yes but they have two or four trackers - but I've got only ONE cable.

Is it possible to bridge the 450/200 from four to one tracker?


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