Would it be possible to use one (larger) MultiPlus-II and use it to supply power from the battery to all three phases (when the battery has sufficient charge)? I have a three-phase connection at home.
Almost all the appliances in the house are connected to phase 1. Phases 2 and 3 are used for electric cooking and charging the car, in addition to a few smaller appliances. Would it be possible to use one MultiPlus to distribute power from the battery across all three phases for everyday use? The car would continue charging from the grid because of the high power demand.
Would this be possible, for example, by connecting ACout 1 to phases 2 and 3?
Essentially you are talking about moving loads off the other phases onto the L1 multiplus phase.
I have a 3 x 40A supply at home.
I have 10kVA worth of inverter on L1, all loads on AC OUT 1.
All loads were moved from L2 and L3 onto L1, so the house is pretty much single phase now with L2/L3 ignored.
Yes, you can re-wire your house to be supplied only from L1 where the MultiPlus is connected, but you will have to make sure your car charger and cooker remain connected before the MultiPlus (AC-in side). Also makes sure you do not exceed maximum current MultiPlus-II can pass through. External energy meter might also be necessary depending on your use case.
Most countries in Europe meter the sum of all phases.
If you push 3 kW on p1 into grid while drawing 2 kW on p2 and 1 kW on p3 the sum is zero.
Consequently your grid meter will show zero W and you will be charged nothing.
The biggest single MP2 allowed is the MP2 6k5 which will be throttle to 4.5 kW while connected to the grid to cater for phase imbalance.
With a 1p Victron on a 3p grid I recommend grid parallel installation. If you are keen on power supply during grid outage add some CEE power sockets on AC_out and proper safety devices.
In Germany, 1 MultiPlus in a three-phase system is only permitted up to 4.6 kW of inverter power because of the phase imbalance limit. However, I can’t say how this works in the Netherlands.
Charging a car and cooking electrically are not small loads, but large ones.
As @BjoernK has already suggested, an ESS system would be the first option to consider.