Re: IGBT Brick hits 1200A

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

Sounds like you need a simple snubber (resistor-capacitor) across the diode
to supress the ringing.
I have some detailed MathCad/Pspice calculators / simulations for precise
snubber design if you are interested.
Contact me offline.

The Captain


 > >The ringing appears to be caused by the fact that the IGBT
 > >is trying to turn off during the haversine when the IGBT elements
 > >are conducting current.  I would think that turning the IGBT off
 > >about 2uS earlier [during the diode haversine] would accomplish
 > >smoother commutation.
 >
 > As far as I can tell, it _is_ being turned off during the diode conduction
 > period. The ringing is just the diode recovery transient.
 >
 > I'll recheck that, but I think if I _had_ been turning it off while the
 > IGBT was passing current, with no snubber, I would have blown something.
 >
 > Steve C.
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