Hi,
If using a set of Multiplus-IIs in a grid-tie system, could there be issues if I added a non-Victron ac-coupled inverter on the grid-side of my Victron system&house, and this inverter is also capable of islanding/running off-grid in a grid down situation?
I'm considering getting a used EV battery pack hooked up to an inverter compatible with 400v batteries. It might be reasonable to put it on the AC-OUT side of my multis, but then the output would be limited by the factor 1.0-rule of the multis. By putting a larger inverter on the grid side of the multis, I'd be eligible for better compensation when participating in grid support service or virtual power plant type schemes.
So I was prioritizing output power to/from the grid over grid down capability until I saw that some Solax or Sungrow inverters can be had with fast (20 ms) switchover to off-grid mode in case grid is lost. So I got curious.
Would my Victron system likely be wired in parallel or in series with the Sungrow inverter?
If in parallel and if both systems are running in inverter/off-grid mode, is there a risk they would interfere with each other given the small grid. Risk of danger?
If in series, I imagine the Multis would sense grid down first and be first to go off-grid, isolating the Sungrow inverter, which would go off-grid moments later, allowing the multis to open back up to the Sungrow "grid" side after some delay. And then any excess load not supplied from the 48v Victron system would be drawn from the Sungrow inverter, right? Risks or issues here?
Just exploring my options and trying to learn a bit along the way.
I have 3x Multiplus-II 3000 running in 3-phase ESS with 10kWh of 48v lithium batteries and a bit of DC-coupled PV.
