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martynhulsman avatar image
martynhulsman asked

3-phase system from 1-phase grid, with PV and ESS?

Hi,

I am hoping someone can maybe assist me and check if my thinking is correct then.

I have a friend that wants to create a 3-phase system from a single phase grid connection.

We live in South Africa, so we struggle with load shedding (you can google what that means) which means he will need batteries for when the grid is off. He also want to have PV and push back into the grid. First question: Will it be possible for him to create the 3-phase system, have PV, have back up generator, have single phase grid supply, and have a battery storage system?


I understand that you can create the 3-phase system by using the master/slave configuration where the ACin goes into the inverter L1 and charges the batteries, and then L2 & L3 generates the second and third phase from the batteries. Will my friend be able to push back into the grid if he connects the PV system to the batteries with MPPTs?

Any help would greatly be appreciated.

Thank you.

Martyn.

3 phase
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mvas avatar image
mvas answered ·
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Alexandra avatar image
Alexandra answered ·

@martynhulsman

No pushing to the grid will not be possible neither will ESS.

Three phase config with swtched as a group unchecked will be the way to go. And I am not totally sure, but grid code is also not an option. Could be corrected on that.

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martynhulsman avatar image martynhulsman commented ·
How can ESS not be possible if you will need the batteries to run the other two phases?


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Alexandra avatar image Alexandra ♦ martynhulsman commented ·

How can the features of ESS work without a grid connection? The point of ESS is grid connection and mixing solar and batteries.

Almost all the features fall away without grid. You will be discharging on two phases and trying to charge on one as an example. So phase compensation can't work. I could go on. it cant control depth of discharge. It won't be able to charge on the one phase faster than the other two discharge at higher loads.....

In the setttings as soon as you disable switching as a group, you will not be able to program ESS and more so if you have three phase AC PV.

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martynhulsman avatar image martynhulsman Alexandra ♦ commented ·
Ok, would it be possible then if I add a 4th inverter to manage and charge the batteries?

Also I did mention that there is a single phase grid connection.

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