Grid tie inverter for 3 phase grid

[ronoz]

Hello,

My home has 3 phase grid.
Which inverter do I need?
In case I will connect a regular micro grid tie inverted will it only supply power to the phase it is connected to?

Thanks

[Sunking]

You need three inverters that can be used and configured 3-phase.

[foo1bar]

You need three inverters that can be used and configured 3-phase.

Enphase has microinverters that do 208VAC 3-phase.
http://enphase.com/global/files/M250_DS_EN_60Hz.pdf

BUT

ronoz - are you sure what you have is 3-phase power? If so - what exactly is the service that you have?

If you're in the US, the above 208VAC 3-phase microinverter is very very very UN-likely to be the right thing for you. Most every residence has 120/240VAC single-phase power. Some farms have different setups, but even those I think aren't likely to be 208VAC 3-phase. You *could* be the odd exception that you actually have 208VAC 3-phase.

[Sunking]

Enphase has microinverters that do 208VAC 3-phase.
http://enphase.com/global/files/M250_DS_EN_60Hz.pdf

Most manufactures do make their inverters 3-phase capable, it just takes at least three of them. With the Enphase will take at least 3 inverters and you have to work in 3's.

[Bikerscum]

Solaredge has 3 phase inverters that work with their optimizers... http://www.solaredge.us/groups/inver...solar-inverter




Would 3 still be needed?

[inetdog]

Solaredge has 3 phase inverters that work with their optimizers... http://www.solaredge.us/groups/inver...solar-inverter




Would 3 still be needed?

If the manufacturer has a three-phase inverter, that would be fine. And it would have the advantage that, for a string inverter, you could connect all of the panels to the same inverter.
Otherwise if you use three separate single phase string inverters you would need to divide the array up into three isolated equal size segments OR get string inverters that can link together to coordinate the Vmp they are trying to reach. One inverter would rule the MPPT scanning and the others would follow.

[Mike90250]

And don't forget, 240VAC single phase, 208VAC 3 phase. So the inverter should match the frequency and expected voltage range. A 240VAC inverter is not likely to qualify on 208V

[foo1bar]

Most manufactures do make their inverters 3-phase capable, it just takes at least three of them. With the Enphase will take at least 3 inverters and you have to work in 3's.

You don't have to work in 3's according to enphase's installation instructions or sample wiring diagram.

For example, their 215 size microinverter can have "up to 25" on one branch.
25 isn't a multiple of 3.

Having a non-multiple of 3 will mean it's not balanced if all of them are producing.
But every time one of the panels gets shaded it'll be unbalanced anyhow. So probably 250W of difference between the legs isn't enough to really make much difference in general.

Of course it wouldn't be a good idea to do a big array all onto one phase. But it looks to me like doing 7 panels on one leg and 8 on the other is not going to be a real problem.