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andy156 asked

Quattro grid with ac coupled inverter and full battery. Can it cope if grid fails during max output

I have a quattro 10000 with 8x US5000 arriving soon. I have an existing solar edge hdwave 5000. I did ask some questions about the sizing earlier but have a specific case that I'd like to check on with regards to connecting the solar edge to the essential load side.

My setup is good for the factor 1.0 rule and the 8000va is > than the 5kw output of the solar edge so that is all good. However I will have 18kW of generation so the batteries will often be charged 100% quite quickly. The extra 10kW is supplied by two Victron MPPT with an oversized array. There is no export limit at the property so there could be a situation of battery 100% and the Quattro+Solaredge exporting at 15kW with very little load. If the grid falls over then are we in the situation according to the 2.2 example. Would there be a big enough lag to raise the frequency and the solar edge responding resulting in damage to lots of expensive hardware?

I would like to have the extra power the SolarEdge provides primarily for the winter months. We had 8 days without power last year so every bit of generation is important. But at the same time I don't want to destroy any equipment.

Thanks



MultiPlus Quattro Inverter Chargerquattro 10kva
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3 Answers
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greendovefarms answered ·

The best I can suggest is to lower the charge limit of the AC inverter so it has ample time to change the frequency and reduce its output, half a volt should be enough depending on your battery chemistry and your MMPT DC system will continue to charge the battery.

As MMPT chargers are very quick to react and reduce loads.

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andy156 answered ·

Thanks for this. This would work if the grid had already failed but I still see an issue if the grid is running and the battery is full.

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andy156 answered ·

Having thought about this more, does it mean that if I am following the factor 1 rule then even if the batteries are 100% full the Quattro has sufficient capacity to 'absorb' the extra output until the frequency changes regulate down the solar edge inverter on the AC OUT? Ie if I am following the factor 1 rule am I guaranteed to not break equipment in all scenarios?

At the moment I'm fitting it before the quattro with the idea of having a switch over to connect it to the AC OUT. However, if the APS relay is made will the solar edge still stop producing power in the event of a grid failure?

Thanks

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