In my neighbourhood we have issues with a high grid voltage during sunny days, problems are mainly that my AC-OUT connected solaredge inverter will sometimes stop functioning ( i do have the inverter configured for throttling) and i think the RS systems themselves are also trothling at say 250v?
This high voltage is sometimes giving problems while on a sunny day with low prices filling the battery, as the grid voltage is still to high during charging, the solaredge inverter is switching off, stopping charging, while DESS demands charging at that moment causing more import then actually necessary.
My question is, would it be possible to disconnect the rs system from grid at say 249v grid voltage (untill battery is full) and then re-connect again? (like switching of the main grid connection manually when it reaches +249v and reconnecting again when its lower or when te battery is full). I asume this would be possible with node-red? Or maybe this would be a bad idea?
Would love to hear other options as well when dealing with these high grid voltages on sunny days / moments as wel..
Check out if you find appropiate elements in NodeRed to read grid voltage and open/close grid connection.
If you experience high grid voltagesoften, I recommend to stay disconnected most of the time. This will provide you with stable voltage for your electronics.
If needed charge your battery from grid with a used PSU like Huwai or Eltek FlatPack. They accept wide range of voltaga and any bad grid. The PSU can be controlled via MQTT/NodeRed or the AC-side can be via Shelly or a secondary relais.
Inverter grid settings control both high and low disconnect/reconnect parameters.
If you choose a specific grid code these are locked in.
With type “other” you can configure them manually.
The high/low voltage protection Zamel Exta PMR-31 and Hager ESC464 are mounted and tested.
It’s mounted in such a way that during a blackout, the Hager main relay stays closed.
Only during a low/high voltage, phase failure, phase rotation in reverse or the Zamel relay fails, the Hager main relay will switch to open.
This Zamel output relay is energised when everything is within its limits, the Hager main relay is then not energized as can be seen by the red led.
Output 2 from the Cerbo is connected in series (by a 24V powered Finder relay) with the Hager main relay coil and the Zamel output contact, so, in case of a failure of the Zamel relay or grid we can switch the Hager main relay also manual in VRM.
We used this NC (normally closed) Hager main relay, instead the usual NO (normally open) relay.
This, not to have the coil energized 24 hours a day and generating 20W of heat and consuming 60+W of power.
