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chriss83 avatar image
chriss83 asked

Fronius on ESS without MG50?

Hi there,

since Fronius Support is taking some time to answer the question, I might as well post it here.

The local utilities require a specific cosPhi setting in the inverter, which - for my knowledge - requires a countrysetup other than MG50.

How does changing from MG50 to i.e. DE2U affect the behaviour of the inverter in an ESS?

Feed-in only needs to be limited to 70%, so no zero feed-in required.


As always, thanks for the help!

Chris

ESSFronius
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4 Answers
Rob Duthie avatar image
Rob Duthie answered ·

You only add the MG50 if you are using the Fronius on the AC output of the Victron, if on the input side of the Victron use your normal country code to comply with.

Regards

Rob D

NZ


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borisut avatar image borisut commented ·
I have this Situation attaching Fronius to the AC out. As I use the Bypass I would like to use the correct Grid code so that this works when the multiplus fails.

Question is what happens if the network fails. Is the multiplus still controlled by ethernet or the frequency shift?

I don't find any clear advise

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Rob Duthie avatar image Rob Duthie borisut commented ·
Hi

Yes it will still shut down as per grid code, as when doing the setups you install the country code then install the MG50 code next then all is well with grid protection etc.

Regards

Rob D

NZ

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alan avatar image
alan answered ·

In an ESS with a PV inverter Ac coupled to the multi output, the system is controlled by Modbus-Tcp.

Frequency control is only used if the grid has failed and the multi can control its output frequency.

In the ess while grid connected, the grid interaction is controlled by the multi and the grid code, with reactive power control set in the multi.

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chriss83 avatar image chriss83 commented ·

Perfect answer I was looking for, many thanks!

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baxter avatar image
baxter answered ·

Hi,


same issue here. My provider requieres the national grid code to be set in the Fronius on ACout of an 3~ ESS. No issue if grid is available, but whats in case of a grid failure?

Will that work in general and what are the drawbacks using the national grid code in the Fronius instead of MG50?


TIA

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

The MultiPlus is the connection to the grid and will disconnect from it if something is wrong.

So there is no need for the Fronius to use the normal grid code.

If the Fronius is not set to MG50/60 it will most likely not start in case of a grid failure.

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baxter avatar image baxter Matthias Lange - DE ♦ commented ·

AT is different ;)

In case the Multi provides a grid within the reconnect range of the Fronius (47,5 - 50,05Hz) it should start?

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ baxter commented ·
The frequency is not the only thing. The Fronius is also checking the voltage and the grid impedance.

The correct grid impedance is the thing a MultiPlus can't match.

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baxter avatar image baxter Matthias Lange - DE ♦ commented ·
According to Fronius Dev Department it works with the national grid code. P(f) is not working as good with MG50 but sufficient. As it is an ESS that should be just fine
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borisut avatar image borisut Matthias Lange - DE ♦ commented ·
The issue above is the usage beind a Bypass that needs Fronius to be set on reginal grid code. MG50 would be not correct in this case. Is MG50 mandatory if the feiniua needs to be controlled behind ACout?
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baxter avatar image
baxter answered ·

Update: Fronius Symo off-grid with AT1E (grid code Austria) works fine.

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borisut avatar image borisut commented ·
Fine is nice but what happens if grid is off and the batteries are full?
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