I have two separate systems where I experience the same problem. Both with Quattro inverters and with a grid-tied solar on the output side of the Victron inverters. In one system it is a Sunnyboy solar inverter and on the other, it is a Fronius. When the grid fails and the system goes into invert mode the solar inverter shuts down momentarily. I think this is because the municipal voltage varies quite a bit and when the grid fails the inverters instantly switch to an output voltage of 230V instead of the 240V that was supplied by the municipality, which will then cause the phase-locked loop in the solar inverter to lose synchronization and shut down. The municipal supply voltage can vary quite a bit, unfortunately, and as such the situation of a difference between the supply voltage and the Victron's voltage cannot be completely eliminated.
My question is this: What is the voltage and frequency output response of the inverters during a grid failure? Does it shift to the set voltage gradually over the course of several seconds or is it instantaneous?
Also, any thoughts on solving the problem of the solar inverter switching off would be greatly appreciated.
