Very interesting concept. Ive not seen it before.
Hello LM thank you for your reply, me too
I came across it some years ago drawn by a guy looking for help with a Chinese GTI that kept blowing Mosfets, at first I thought he had drawn it wrong but apart from changing a few diodes to zeners it seems to work perfectly except.... said problem of unreliability. His GTI was a simple 12/24V 300W plug in the wall type. I just wondered if anybody had encountered a circuit like this in big multi-kw grid tie's.
I should mention that what the drawer labelled as +/-360V is actually the output from a high frequency pwm and is in fact a 100hZ unipolar sinewave. This circuit (H bridge) is sometimes called an inverse rectifier, sometimes an unfolder and I am sure has several other names too, I have also seen thyristor implementations.
At the moment my GTI unfolder is as I say a traditional hard switched H bridge using timing derived from the microprocessor that ultimately is derived from the grid zero cross however I have lost a mosfet in unexplained circumstances so if that happens to often I may try this one except I dont have a pcb for it at the moment and its hard to do high voltage stuff on breadboards.
Anybody out there torn down there GTI to know what the active circuit is immediately before the grid connection ?