question

mohammed-algaolahi avatar image
mohammed-algaolahi asked

About Combined AC-DC Coupling system in isolated area "NO GRID And No generator"

In my remote setup devoid of grid connections or backup generators, I have two solar systems in place:

  1. An 80 kW solar array linked to an 80 kW Sungrow inverter, initially set up with a generator which is no longer available.
  2. A 45 kW solar setup connected to three Victron Quattro inverters via MPPT chargers, supplemented by 192 kWh of battery storage.

My inquiry pertains to integrating a grid-tied inverter with the AC-coupled point of the Victron inverter system to operate the setup. Specifically, considering the average load of 30 kW, could surplus power in the AC line be directed towards charging the batteries? Additionally, I'm interested in ensuring the safety of the system and whether the frequency shifting feature in the Victron inverters would provide stability to the setup.

waiting for your feedback and most regards!!

ac couplingQuattro-II
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Alexandra avatar image
Alexandra answered ·

@Mohammed Algaolahi

There is a factor 1:1 rule with AC coupled PV. There are some linked resources on this page.

So for 80kwh of solar a 45kVa Victron system is too small. They should only be used supported if they frequency shift.

Yes they will charge the batteries the inverters are bi directional. It works them hard though so make sure the room is kept at a good working temperature.

As a further thought, you can switch some of the PV to DC coupled (not sure how you are set up and the practical value of the suggestion) that way you can use the solar that is there without breaking the factor 1 rule.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Quattro II Product page

Quattro II Online Manual

Pre-RMA bench test instructions.

Additional resources still need to be added for this topic

AC-coupling and the Factor 1.0 rule


AC-coupled PV with Fronius PV Inverters



Additional resources still need to be added for this topic