Re: DRSSTC thoughts...

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

Original poster: "Greg Leyh" <lod-at-pacbell-dot-net> 


>Original poster: "Steve Ward" <steve.ward-at-gmail-dot-com>
>Hey Terry,
>
>[snip]
>
> > I see that super high current IGBTs are really in demand now ;-))  But
> > monsters like the fabulous Powerex CM600HA-24H my be too heavily designed
> > for "power" when what we need is "current".  It can "officially" do 1200
> > amps peak which is nice but I know we don't need the 4200 watts of power
> > dissipation ;-))
>
>Yeah exactly.  They also didnt strive to minimize stray L inside the
>bricks either.  Greg Leyh wrote an article on this... cant remember
>where to find it though.  As we push these IGBTs harder and harder the
>little things like stray L inside the IGBT will add up quick!  And
>heck, we'd be doing something bad if we dissipated over 50W per IGBT
>(unless it was a REALLY big system).  Even with making 11 footers, my
>IGBTs stay cold to the touch.


Here's one paper addressing the inductances of internal busbar structures in
'brick' style IGBTs.  We designed and built prototype brick IGBTs for both
3300V and 6500V service.  Test results are shown.
http://www-group.slac.stanford.edu/esd/IGBTPAC2003.pdf

Another paper addresses some of the issues regarding stacking IGBTs into a
500kV, 550A Marx Bank.
http://www-group.slac.stanford.edu/esd/PESC04_Paper.pdf

The internal emitter inductance is important even for slow applications, 
since this will
largely determine the survivability of the device during fault conditions 
such as arcing
or overvoltage.  Large or uneven emitter inductances can cause internal 
ringing,  hot
spots and voltage overshoots that can destroy the device.