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mihaimicu avatar image
mihaimicu asked

Fronius + victron feed-in during absorbtion

Hello and happy new year. I have a issue with zero feed in during absorbtion. My system is a fronius symo 8.2 with 1 multiplus 48/5000 connected on L1 AC out. When my pylontech batteries are in absorbtion the zero feed.in is not working well. I have setup the grid setpoint to 150 W but it keeps exporting arround 100 w. During bulk the grid setpoint is beeing followed. Can someone help?

screenshot-20210103-122028-samsung-internet.jpg

Fronius
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4 Answers
mihaimicu avatar image
mihaimicu answered ·

Some more screens. The pics from the gx are just for reference. I did not make screens during the export.screenshot-20210103-122938-samsung-internet.jpgscreenshot-20210103-122904-samsung-internet.jpgscreenshot-20210103-122630-samsung-internet.jpg


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mihaimicu avatar image
mihaimicu answered ·

Cant anyone share a point of view? I believe that the export is a result of a bug ? Victron is feeding the overvoltage in the grid during absorbtion phase? The ESS assistant is configured as per instructions for pylontech 48V batteries.

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thomasw-1 avatar image
thomasw-1 answered ·

Hi @Mihaimicu,

You mention that your Fronius is connected via phase L1 to a single MultiPlus. Am I right with my assumption that you have only a single MultiPlus, where you connected the Fronius L1 the Symo on AC-OUT L1 and Symo L2 and L3 are natively connected with the grid.
Btw. I have never heared about such config before and I would be surprised that it works with phase sync, in case MultiPlus disconnects. In my country such config would be most probably not allowed. In network outage I am not really sure, if Symo switches off in order to assure network separation.

In order to avoid more confusion could you please provide a more comprehensive description of your layout and configuration?

In case my assumption is right, I could explain the behaviour.
Could you please export from VRM the data in Excel format and provide it. In that case I would delve a bit more into your topic.


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mihaimicu avatar image mihaimicu commented ·

Hi @thomasw-1 . My enviroment is like this.

Grid- EM24 meter - fronius symo L1 connected to the output of the multiplus. L2 and L3 of the symo are connected to the grid like normal. Two pylons 2.4 kwh connected to the multi https://vrm.victronenergy.com/installation/78418/share/4ddf5ad0 i shared my installation. Today made again export during absorbtion phase.



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thomasw-1 avatar image
thomasw-1 answered ·

Hi @Mihaimicu,

With your current setup you cannot prevent that 2 phases which are directly connected to grid do not feed-in. The design of the Fronius Symo cannot control the inverter power on 3-phases separately.

  • Either it generates power or not.
  • Either power limit is applied on all 3 phases or not.

As a consequence, when you use power phase, which is used on AC-OUT of your single MultiPlus, then power will also flow into the 2 other grid-directly attached phases.

I hope that explanation helps.

Cheers,
Thomas
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mihaimicu avatar image mihaimicu commented ·

Hi. I have installed a em24 meter. And the ess is setup with multi phase compensation which works. Only in absorbtion when batteries are fully charged. There is export!

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thomasw-1 avatar image thomasw-1 mihaimicu commented ·

Hi @Mihaimicu,

What should limit single phases, when you have nothing that can limit the energy flow on relevant 2 phases?

  1. Be conscious, on relevant phases you do not use a MultiPlus.
  2. The meter only meters, but is not capable to limit the engery flow.
  3. As I decsribed in previous post, the Fronius Symo cannot be controlled on individual phases.

So the setting of multiphase compensation cannot have any effect in your setup!

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mihaimicu avatar image mihaimicu thomasw-1 commented ·

Not correct. With multi phase compensation it works. Together with the em24 meter. L1 + L2 + L3 = grid setpoint. This means that even with only 1 multi on L1 it throttles the fronius to keep the grid setpoint. And it works perfectly. Only that when in absorbtion phase it exports a few w.

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laurentiupitran avatar image laurentiupitran commented ·

Hi,

please, see attached graph; there is set ZERO injection in the system.

easely you can see that is energy used from grid when is plenty energy from PV , as well as energy injected on grid when not necessary, as the battery is not full.....example-ess.png

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example-ess.png (97.8 KiB)

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