question

meshugga avatar image

Wind Charger - Unstable MPPT

I have 2 x 150/35 and 2 x 100/20 MPPT's controlling 20 x 100 w solar panels. I also have 2 x D400 wind chargers with their own controllers. All connected directly to a 24 v 1200 ah battery bank

Every time there is a gust of wind, the output from the MPPT's is reduced for a few seconds - I presume because the MPPT's sense a slightly higher voltage and need to adjust to that new parameter? Is there a setting on the MPPT's that can be changed to overcome this fluctuation?

I also have 2 x 24/5000/120 Multiplus. When running my Genset and the Multi's are charging, the MPPT's supply zero power. The same thing happens when my main engine is running and the alternators are supplying power. It would be preferable if the MPPT's continued to operate normally and the charger/alternator power was reduced. Is there a solution to this?

I have an MK3 interface to change the parameters.

Thanks


Hydro and Wind Power
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3 Answers
boekel avatar image
boekel answered ·

What voltages are set in the MPPT's and wind controllers, and what voltages are reached when there is a gust of wind?

(same question for the Multiplus btw)

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Thanks. I'll measure / check voltage settings on all and revert.

JohnC avatar image
JohnC answered ·

Hi M. The mppt vs wind fluctuation is what you'd expect. They're targeting a V, and will adjust output to suit. That won't hurt them, and as the V is your target, a fluctuating V might be of concern. Given these things can't be expected to react 'instantaneously', maybe you're expecting too much of em?

If you set the genset target V in the Multi to slightly lower than the mppt's you'll find the genny will backoff in deference to the mppt's. How much you need via trial'n'error, but it shouldn't be much.

The alternator an unknown quantity in this regard. If it pumps more V than the mppt target V, then it will take over. What to do re that might mean an on/off switch if you're happy for the mppt algorithm to control what you do with the batts. Maybe the same applies to the wind unit too?

Bear in mind the mppt's aren't synchronized and will each have their own view of what V they want (Ie Absorb or Float). That shouldn't be too much concern, and minor adjustments to an extreme offender might be needed.

What you have is 8 chargers, each with it's own target(s). Which ones defer first is for their relevant settings. Make any sense?

Typed most of this before Boekel posted, but he's onto it too. :)


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Hi JohnC

Ah-ha. Suppose I should have thought of that. Makes total sense. I'm going to draw up a spreadsheet of all the output voltages & settings with my priorities/intended settings. Both my wind turbines and smart alternator regulators permit me set their bulk voltages, so I should be able to tweak as suggested. Then I'll post these to the site before implementing to check that I'm on the right track. Great input, thank you.

Another Q. I am planning on installing a powered usb hub so that all 4 MPPT's can communicate with my ccgx. Will this enable the MPPT's to communicate/sync with each other, or is this just one-way coms to the ccgx?



No, they still won't sync. That feature must be high on the wishlist of most multiple blue mppt users, and we may well see it one day in a GX firmware update.. Keep wishin.. :)

OK, thanks.

troy avatar image
troy answered ·

It has been confirmed that Bluetooth based multiple MPPT syncing is in the works. Apparently it is in testing already.

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