Brief power interruption when feed-in to the grid stops due to high voltage

[guiooome]

Hello,

I have an ESS installation with 3 MultiPlus II 6k5 units in a three-phase configuration, a Fronius Symo AC-coupled, an MPPT 250/100 DC-coupled, an Ekrano GX and 32 kWh of batteries.
When the sun is shining brightly and the grid voltage rises because many homes on my street have PV systems, grid feed-in stops in accordance with the local settings (Belgium). Every time feed-in is interrupted, there is a brief power cut on the AC OUT side, which causes some equipment (printer, NAS, etc.) to restart.

How can I prevent these power cuts?

Thanks.

[Netrange (Steffen)]

Hello and good morning

That’s exactly what shouldn’t happen

Have you tried comparing the SOC and/or load graphs in VRM when the AC Out switches off? Perhaps some settings are wrong and the MultiPluses are switching off the AC Out as a precaution …

What are the SOC and/or load levels at that time? How is the Fronius connected?

[dennibu]

Hello,

3-Phase MP 2 48/5000 – Problems with battery overcharging during a grid outage

Sure, here’s the clip where I switch off the SLS; I think you can see the moment in the video I don’t think it’s healthy, but I still wanted to test the situation, just so I could experience or see what actually happens in an extreme case.

Jonas s posted a video here on 17 September of his three-phase ESS with AC PV on the AC out. The switchover behaviour during a grid failure is odd for Jonas when the grid fails while the system is producing at full capacity. But this only happens when the battery is full and the AC PV is running flat out.

Have you ever simulated a grid failure under different conditions?

[guiooome]

Thanks for the suggestion, I’ll check it out.