Solar Inverter teardown/theory.

[station240]

Someone locally was giving away a dead Solar Inverter, which sadly I probably want get, as they are completely un-contactable. 

Anyway some poking around revealed Sunny Roo made some craptacular transformerless inverters, which are without warranty as obviously the importer went broke. Given there are other brands/models with the same sorts of issues, shouldn't be too hard to find one to pull to pieces.

[nowlan]

I have been wanting to ask if anyone can explain to me how transformless works. I suppose id have to look at some patents first.

Is it just like our switching power supplies, inductor boost 12-48v up to 300vpk and then pwm/filter 240v sinasoidal line?

When I search for transformerless i only see the 240v buck 12v@20ma via capacitor.

Also curious about how they follow the grid reference frequency. For instance when you have SunnyIsland, they generate 50hz when normal condition, but if a slave device is producing too much power, they speed the frequency along to 51hz to tell them to slow down/back off, and then 52hz or something to tell slaves to go offline.

I would have thought smart meters at my switch box would detect the signal in the street to down, and isolate/island the house's production.