Chowan wrote: could a small pure sine 220 inverter be used to trick the inverter in question into thinking it is conected to grid
That is essentially what I was asking. So far the ‘experts’ are split evenly as to yes or no it will work. The thing is when I synchronize larger inverters in big power installations it does work so in theory it should work.
The question experts have raised so far is that somehow the grid tie inverter would suck power from the little unit. Or at least thaat is how they phrased it. Trouble is I do not have a spare $7000 to buy stuff to experiment with so I was wondering if anyone had already tried this.
For synchronizing bigger installations a clock signal is connected to all the units via a data cable with RJ-45 connectors.
Where the wrinkle creeps in is when the big inverters pump out more power than is consumed. It automatically raises the voltage to make current flow ‘uphill’ to the grid which in this case is a tiny inverter. The question becomes what does the IGBT’s do when the voltage gradient is reversed across the device. At some point they do explode. In mis matched phasing they tend to get very hot then the copper in the heat sink gets molten. I have scraaped enough melted copper out of cases to know what that looks like. <smile>
Naturally none of the manufacturers will provide schematics