AC coupled Fronius Symo Advanced 15 on 3 Multi-II 10kVA with PV assistant.
Works well so far, except in the evening the Multi-II do not lower the frequency when they already could/should IMHO.
Currently the PV capacity connected to DC MPPTs (MPPT RS, Multi RS) and AC (Fronius Symo) is about the same and they also deliver about the same yield.
After a short burp in the morning, when this insanely overdimensioned installation has filled the batteries, the system keeps battery voltage constantly at 54V - float. Most of the time, the 15kW Symo is kept on a leash so it delivers around 75W (there might be optimization potential, but that’s for another discussion).
Now in the evening when the Victron MPPTs can’t deliver enough power to keep the battery at 54V - see picture - the PV assistant still keeps the frequency at 52.6 to 52.8 Hz despite V_bat falling.
Now it DOES start to lower the frequency, somewhere in the range of 53.85V, but that’s IMO a tad too late. Why the hesitation? I wonder if the system has the information whether the Victron MPPTs are throttled or not (anymore). If - as is in evening and low light conditions the case - they are not, the system should have a pretty solid hint not to throttle as much and/or as long.