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RE: IGBT SSTC finally possible?



Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com> 

 >Was thinking it would be nice to make a multi kW, ~600v input, SSTC with
 >some of these. Any reason why this isn't possible

It is possible and several people have done it in the year you were away ;)
The champion is undoubtedly Jimmy H. who has achieved 6ft+ arcs with a large
resonator driven by 150A IGBT bricks (the DRSSTC)

http://www.hot-streamer-dot-com/chunkyboy86/

Steve Ward has also done some neat stuff with his I-SSTC, a setup similar to
Jimmy H's coil. I think he's getting over 4ft.

http://www.hot-streamer-dot-com/srward16/

The "secret" of these coils is that they use a series-tuned primary which
massively boosts power transfer as well as providing the soft switching
conditions that IGBTs like.

Then they design for peak currents in the IGBTs that are 4 to 10 times the
datasheet maximum, and run the inverter in short bursts rather than
continuously so the setup doesn't self-destruct. (This exceeding of the peak
current rating would be impossible with MOSFETs, but IGBTs seem to eat it up
and ask for more.)

For example, the DRSSTC lets off a ~160us burst 120 times a second, and
during this burst the inverter is pumping over 150kW at 66kHz into the
resonator, which is far more than it could deliver continuously without
overheating.

There are also a few people (Dan Strother and Jim Mitchell spring to mind)
who have just dropped the new "warp" IGBTs into the standard SSTC circuit
with untuned primary, and got pretty good results. But it seems the real fun
is to be had by series tuning your primary :)

Steve C.