highlow avatar image
highlow asked

Victron System + Froius Symo Hybid NON MICROGRID!


I would like to install a Victron system on my existing solar installation that is made with Fronius Symo Hybrid.

The project will be like this:
please see configsolar-victron-fronius.pdf attached file

GRID(3PhaseRST) goes to -> IN VICTRON x3 MultiplusII(RST)->(OUTs VICTRON) goest to Fronius Symo Hybrid

All inverters(Victron and Fronius) are set NOT TO INJECT IN GRID. So Fronuis inverter will be set NOT TO INJECT into Victron Outputs in this case because for Fronius inverter will see the Victron's Outputs and is like seeing the grid.For Fronius the GRID is Victron's OUTPUTS. Basically every system will take care of it's own job and will not communicate one with each other, NO MICROGRID here. Every Inverter makes storage of energy and activates it's outputs power when is necessary but WITH NO EXPORT of energy!

So Victorn inverter is coupled with AC GRID (is in sync with the network GRID) and Fronius is in Sync with Victron's Outputs. When the main network Grid fails ... Fronius remains connected to the backup Victron's Outputs. So Fronius will not even see that the main network is down.

In the other mode of functioning ... both inverters will not export enery to Grid and Fronius is limited not to export to Victron either. Like I've said every system will do it's own job not communicating with eachother.

again See pdf file with the possible configuration: configsolar-victron-fronius.pdf

Q1: I wonder if anyone tried any of that configuration and maybe not only with Fronius inverter ... but maybe with other types of inverters that are limited to export? in this case we don't need the Microgrid option activated.

I'm posting this question because I'm only afraid it will not work only of 1 thing :
Fronius is set NOT TO INJECT ENERGY into GRID(this case into the Victron Outputs) but somehow there will still be some leftover injected energy sometimes... like 100W or 200W (for about 1-2seconds) of energy leftovers that escapes the condition part of not injecting.

Q2: Will that phenomenon affect Victron inverter? since also Victron inverter will be set on NOT TO INJECT... ? will some protection be activated on the inverter? even though is such a small escape of energy?
Q3: Could I set Victron to store the leftover Energy into the storage Battery? and not have any issue with the minor escaped energy from Fronius?

Thank you!

Froniusmultiple inverters
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ponzoa avatar image ponzoa commented ·
In your diagram, you're talking about an AC Coupled Configuration. I would suggest you let the Fronius export to Grid as the grid for the Symo is the Multiplus units, that way, the Multis can use the excess Symo power to charge the Victron Batteries. Victron will stop the export to grid for the Symos through the network connection or via frecuency shifting. The Symo will need to be set up for MG50.

You also don't need the Fronius power meter. I would remove it personally. If you have nothing between the Grid and the Multis, you won't need the power meter there either as the Multis have them built within the units.

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2 Answers
highlow avatar image
highlow answered ·

I've implemented the system and is working fine! I'll come in next month with details... Until now the system works great

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highlow avatar image
highlow answered ·

So the system works fine, the only problem is working OFF Grid with Victron.

Fronius injects energy on other phases even though it is limited to 0 injection... Victron tries to reduce power of Fronius by increasing the network frequency to 53Hz and Fronius enters in protection frequency trip... that makes it restart because it doesn't know microgrid function.

At the end I got the system running only in ON Grid situation with no Injection to grid.
In OFF grid the system is working but with restarts of Fronius. Maybe I can deactivate Fronius when grid is OFF (usually being for a short period of time). At this time I don't bother it this situation since Fronius itself is restarting and I don't have other protections raised.

So good luck to everyone that tries this configuration because it is working

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