Multiplus tripping the main grid transformer?

[gyamotab]

Hello everyone,
I’ve posted on the French-speaking forum, but perhaps the global community has some ideas.

We have had several grid outages recently. The transformer that supplies power to the hamlet keeps tripping or burning out—I’m not sure which.

Looking at the data logs, I notice this happens whenever my PV (solar production) drops to zero…?
So, I’m wondering: Could it be my installation that is causing my neighbors to lose power?
The system (standard setup) has been running without issues for 2 years with NiFe batteries: 48V / 2x200Ah in parallel. I can send screenshots of the MPPT and Multiplus II settings, but I haven’t changed anything recently.
I checked the connections to make sure they were tight.

It’s neither the 30mA nor the 500mA at home (which both work with the test button) that trip, but rather the big one on the neighborhood pole.
And today, I got a “High DC Ripple” alarm that appeared at that time on VRM. Apparently, the grid outage happened first (at 21:26) and the alarm came at 21:28.
It’s strange, the alarm does not show up in the alarm log, only on chart.

Screenshots of today:

And from the previous trip:

Thx for you help, I’m lost…

[ASeitzinger (Arno Seitzinger)]

could it be that your system is unintentionally feeding dc current to the transformer? That would saturate the core and cause huge currents on the feeding grid.

[lxonline (LX)]

Not likely. It looks like a brownout condition. The short amount back is the system testing the connection as it is happening. (LOM detection)

We experience them often here and see similar graphs. I can tell you it is not the cause of the problem.

You are pulling nothing to speak of from the grid and feeding nothing to the grid. If the transformer is overloaded then that seems to be an electrical supply problem.

@ASeitzinger

it be that your system is unintentionally feeding dc current to the transformer

For this to happen you (and everyone around you) would literally have to feedback power at the limit of the transformer. (And some of them are 200kw in a neighborhood.) not sure what size you are near so just an example.

[gyamotab]

In such case, how can I monitor the line to check?
Today, it tripped again. I don’t know if the variations are the cause or the consequence. Time of BO: 21:30

[gyamotab]

Finally, they change everything on the grid side. No more issues It wasn’t from the house system…