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romarub avatar image
romarub asked

Issue with Cerbo GX ver.281 in combination Multiplus II and Fronius Primo or Symo

Hi there, after the last update on Cerbo GX to v281 on 31.01.2022 there are some issues with Multiplus II and Fronius (Symo/Primo).

In two of our systems the Fronius connected to the AC outI of the Multi works for a few minutes after {Redetecting} in the {Advanced} line. (Device List/Multiplus II/Advanced/Redetect). Then suddenly the power of the Fronius decreases to 0W and the system discharge the battery according the ESS.

We tried to limit the charge current to 15A in the DVCC wich helps for a while.


cerbo gxDVCCvenus os v2.80
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2 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi @RomaRub ; thank you for the report, we’re looking into it.

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romarub avatar image romarub commented ·

Thank you @mvader (Victron Energy)

On February 10, after updating the Venus software to version 2.82, one of these two Fronius (Primo) started working without our intervention and has been working steadily for the second day. However, we noticed that the power fluctuations from the grid became too large, especially with a fully charged battery. The power from the grid is constantly changing in a wide range from about -1 kW to +1 kW with a fairly uniform energy consumption in the house. This was not the case before.

The other Fronius (Symo) still refuses to work. We again managed to start it manually with {Redetecting} a few times, but every time it shuts down after a few minutes.

In both cases, the firmware of all system components has been updated to the latest versions.

All of our other MicroGrid systems are stable. Probably, there is still some kind of software error that manifests itself only with a certain system configuration.

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romarub avatar image romarub romarub commented ·

These screenshots show abnormal power fluctuations from the grid in a system with a Fronius Primo inverter:

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romarub avatar image romarub romarub commented ·

These screenshots show the operation of another system with a Fronius Symo inverter. The inverter is not working. It can be started manually with {Redetecting}, but after a few minutes it turns off again.


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romarub avatar image romarub romarub commented ·

@mvader (Victron Energy) Fronius Symo still works after several manual starts, but when the battery is fully charged, the situation with feed-in to the grid is very bad. There is an unauthorized feed-in into the grid from 0.5 to 1.5 kW. Please note that the charge controllers did not turn off when the battery is fully charged, as they usually do when Fronius has enough power to maintain consumption.

00988-04.png00988-05.png

Also this feed-in works the same for any phase balancing option, both for "Total of all phases" and "Individual phase".

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In the end, Fronius turned off again, and the problem with unauthorized feed-in to the grid disappeared.

00988-08.png

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romarub avatar image romarub commented ·

After updating to version 2.83, Fronius Symo started working on its own, without our participation, but problems with feed-in remained. Version 2.84, unfortunately, did not improve the situation. Fronius Primo works very well in another system.

00988-feed-in.jpg

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sunnyday333 avatar image
sunnyday333 answered ·

Hi @mvader (Victron Energy)

I have noticed similar behavior. I have downgraded Cerbo GX to v2.73 but the problem persists. This problem only occurs if the battery is 100% charged.

There is a lot of fluctuations caused by Fronius PV inverter because Cerbo GX often changes limit to it via Modbus.The dashed line is a limit from Cerbo GX:

screenshot-2022-02-11-at-153737.png


screenshot-2022-02-11-at-153737.png (891.3 KiB)
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