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micmak avatar image
micmak asked

Prioritize Grid Feed-in over battery charging

Hello,

I have a Quattro and a Fronius in a AC coupled configuration, as well as 2 Bluesolar MPPT. I would like to prioritize Grid Feed-in over battery charging, when Grid is available. I currently do that manually by setting the DVCC battery voltage limit to the current voltage when the grid becomes available. Is there a way more automated to do that within the cerbo gx? I would prefer that before I go the modbus route for this.

The reasoning behind this is that the grid is available for a couple of hours during the day, and sometimes a couple of hours in the evening. I would prefer to be feeding back when it is available, then continue charging the battery when it is offline.

MultiPlus Quattro Inverter Chargercerbo gxFronius
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Alexandra avatar image Alexandra ♦ commented ·
@micmak

What have you set as your min SOC in case of grid faliure? If you set that down it should feed when it is above that level?

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micmak avatar image micmak Alexandra ♦ commented ·
@Alexandra my aim here is to pause the battery charging and let the solar panels power to feed into the grid, while the grid is available of course. Once the grid is offline, the solar panels can resume charging the batteries
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Alexandra avatar image Alexandra ♦ micmak commented ·
@micmak

You can set the DVCC charge current to zero. Automating that is a different story though.

The other way is with an assistant on the inverter itself to set the charge current down when ac input is available or when a DC voltage is or is not applied to the aux sensor input is another option.

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1 Answer
matt1309 avatar image
matt1309 answered ·

If you have ESS setup I would probably try to use Node red with the below Pseudo code to adjust grid setpoint to achieve this. Similar solution to what i imagine you would've done the modbus but instead using node red.
I would personally also add a few other critiera based on your system requirements ie a minimum SoC for the flow to run. ie if below 20% dont export.

Node red should then dynamically adjust grid setpoint each time flow runs. It wont be super responsive if loads fluctuate a lot but it's a work around.


if grid available {

//if sufficient solar

if (Loads - solar > 0) {

set grid setpoint = -(loads - solar)

}

}

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