Splitting DC into 2x Inverters

[jon.clapham]

Hi,

I will shortly be installing a 5kw wind turbine from Tesup. However, the Tesup charge controller is 4kw and the only inverter they supply compatible with the UK power grid is 2kw (badged Growatt). I appreciate the turbine will not go above 4kw unless we have extremely high wind and so I'm happy to accept 4kw. However, the 2kw drop for the inverter is too much for me to swallow. Can I split the dc into 2 inverters by placing them in parallel and therefore potentially receive 2x 2kw on the ac side? The output from their charge controller is 48v and I cannot find an inverter larger than 2kw with an MPPT startup of 50v or less (this would be too easy).

 

[Samsonite801]

Hello my friend... My apologies, I am a bit confused in understanding the full intent of the query. Hopefully you don't mind if I ask a few more questions to see if we can get in better sync here...

So Tesup has a 4kW charge controller? Can we just use that (assuming it's built for managing a 48v battery bank), and it can charge on the battery directly? ...And not use the charge controller built into the Growatts (if it doesn't have the capacity on a single MPPT input)... As far as All-In-Ones go, we need to maybe be careful to call it simply an inverter here, because it is that, but is also a charge controller, they may have different ratings between MPPT PV input specs, and inverter specs.

I guess I don't understand the other question:

"Can I split the dc into 2 inverters by placing them in parallel and therefore potentially receive 2x 2kw on the ac side? "

Which Growatt model is it? What are the PV input specs on this all-in-one you're referring to? Can you just use a separate charge controller that has the specs you want to manage your battery bank for charging, and then only use 2x Growatts as far as inverter on the AC output only (providing you use a stackable model)?

Note, that they are only stackable on the AC output, you cannot stack or parallel the PV inputs, or you will get 2 MPPT controllers trying to manipulate against the same input circuit (fighting against each other).

 

[time2roll]

Easy to connect the DC side to a common bus. Need to read the manual if they are compatible to combine output.
According to the above post they are stackable.

 

[sunshine_eggo]

this one?

TESUP_MAGNUM5_Wind_Turbine_User_Manual.pdf

drive.google.com

 

[schmism]

Ill phrase this in terms of solar. Its my understanding that the "source" of DC is irrelevant for the example.

4Kw PV -> 4kw MPPT SCC ->Battery -> inverter ->Loads (including which could include the grid)

4kwPV into two 2kw "parallel SCC" does not work, they "fight" each other over the incoming DC

to do what you want.

4kw DC source -> charge controller -> battery -> whatever you need to power the load. (2 -2kw inverters, 1 -4kw, 4 -1kw etc)

The battery looks like a constant current source to whatever inverter is powering the load. You could "split" that between local loads or grid loads whatever. point is when there is insuffenct battery, all loads are shut down at the same time.

 

[Samsonite801]

Easy to connect the DC side to a common bus. Need to read the manual if they are compatible to combine output.
According to the above post they are stackable.

Yeah but I understood (based on what I thought I read there) that he wants to know if he can parallel a single wind turbine DC source to 2x MPPT inputs?

 

[time2roll]

I see a kit with 5kW turbine, 4kW controller, 2kW inverter. And wants 4kW of AC power requiring two inverters.
I assume there is a battery buffer between them.... maybe not so max power would be 2kW. Actually 2 kW might be a realistic maximum.

 

[Samsonite801]

I see a kit with 5kW turbine, 4kW controller, 2kW inverter. And wants 4kW of AC power requiring two inverters.
I assume there is a battery buffer between them.... maybe not so max power would be 2kW. Actually 2 kW might be a realistic maximum.

Well hopefully if that's what he meant, just to bridge the battery bank, that's usually how you'd do it anyway when you start stacking inverters. I guess we'll find out what he meant when he responds back.. Hope you're right, that makes it easy

Just make sure the the Growatt model he is wanting to use supports stacking because not all of them do.

 

[sunshine]

However, the 2kw drop for the inverter is too much for me to swallow.

The Tecsup CC is actually - Single device for upto 4 KW power management (0 to 4000 W) .Take note of "upto'' since the output will rarely be anything significant.
You can add any size inverter after the batteries as the 2kw one is only a suggestion since it is probably the most requested.

 

[schmism]

I guess my response was to difficult to understand. Ill try again.

...can parallel a single wind turbine DC source to 2x MPPT inputs?

No.

 

[Samsonite801]

I guess my response was to difficult to understand. Ill try again.


No.

Yeah that's the same thing I said before in my first post on the last paragraph...


The quote you put above (from me) is out of context and it's NOT what I said...

I did not say "...can parallel a single wind turbine DC source to 2x MPPT inputs?"

But rather I really said: "...that he wants to know if he can parallel a single wind turbine DC source to 2x MPPT inputs?"


Meaning, when I read his first post, I had the interpretation that the OP had been asking if that is ok to do. So then in the last paragraph of my first response above, I said:

"Note, that they are only stackable on the AC output, you cannot stack or parallel the PV inputs, or you will get 2 MPPT controllers trying to manipulate against the same input circuit (fighting against each other)."

 

[markansas]

Hi,

I will shortly be installing a 5kw wind turbine from Tesup. However, the Tesup charge controller is 4kw and the only inverter they supply compatible with the UK power grid is 2kw (badged Growatt). I appreciate the turbine will not go above 4kw unless we have extremely high wind and so I'm happy to accept 4kw. However, the 2kw drop for the inverter is too much for me to swallow. Can I split the dc into 2 inverters by placing them in parallel and therefore potentially receive 2x 2kw on the ac side? The output from their charge controller is 48v and I cannot find an inverter larger than 2kw with an MPPT startup of 50v or less (this would be too easy).

would this work for you?