I have an off-grid system with 3 x 5KVA Phoenix inverters in parallel. I have MPPT regulators to charge my Pylontech batteries. All of my solar arrays face north (I'm in the southern hemisphere) and I would like to install a small west facing array (1.65kW) to utilise the last light of the day.
My problem is that the only place I can feasibly locate the array precludes any cables being run (DC, or communications) back to the main equipment room. It would seem that AC coupling is the only option available to me, but my searches of topics relating to this all seem to talk about Multiplus and Quattro inverters, frequency shifting and battery charging.
I don't care about battery charging, my MPPTs more than take care of this for most of the day. I just want to utilise the available sunlight as late in the day as possible, to assist with the AC load (which would also reduce the late afternoon discharge of the batteries for a while.)
My questions are:
Is it kosher to simply connect a Victron approved AC coupled inverter to my single phase service (I do have a sub-board in an outbuilding with 10mm2 cable running back to the main board)? If so, will the Phoenix inverters and the AC coupled inverter be configurable so that the AC coupled inverter is fully utilised - in other words, can the Phoenix inverters be configured so that they don't try to hog the load late in the afternoon, using the batteries in the process, if the AC coupled inverter is able to provide sufficient output? Do I need any form of communications connection between the Cerbo GX and the AC coupled inverter, or between the Phoenix inverters and the AC coupled inverter?
Edit: Further reading makes me think that the terminology I should be using is "grid-tied" as opposed to "AC coupled". In my case my existing Phoenix inverters are my "grid". Either way, my questions are the same.
Thanks
Rusty
