Re: Please help ! IGBT exploded ...

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

Original poster: "Rajesh Seenivasan" <rajeshkvs-at-hotmail-dot-com> 

I havent given enough info again ...
the gate drive voltage goes to +/- 5 volts in 700ns-800ns time, and
eventually reaches +/- 15V after some time.
I mentioned the timing for you to imagine how much 'dead' time is being
given by the gate drive waveforms.
Sorry again ...


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, March 09, 2004 9:48 AM
Subject: Re: Please help ! IGBT exploded ...


 > Original poster: Sean Taylor <sstaylor-at-uiuc.edu>
 >
 > On Mon, 08 Mar 2004 19:52:16 -0700, Tesla list <tesla-at-pupman-dot-com> wrote:
 >
 > >Original poster: "Rajesh Seenivasan" <rajeshkvs-at-hotmail-dot-com> Hi Mike,
 > >
 > >The bottom transistor on one leg of the H bridge exploded. (It shows
short).
 > >The gate drive waveform of top and bottom igbts crossed each other at 0
 > >volts
 > >and increased from 0 to +/-5 volts in 800ns (very slow rising edge ?).
 > >I had 3.3 ohm resistor in series with gate.
 >
 > Sorry, forgot to mention, +/-5 volts is a pretty low voltage for a gate
 > drive - should get to at least 10V, and totally switch from one voltage to
 > the opposite (on to off or off to on) in under several hundred nS -
 > depending on how good your driver is at achieving ZCS.  Try using a good
 > high current gate driver chip like the TC4420, or TC4421/2, or there's a
 > couple TI chips, but I've never used them.  I can't remember the part
 > number off the top of my head, though I think Steve Ward's site (on
 > hot-streamer) has the info . . .
 >
 > Sean Taylor
 > Urbana, IL
 >
 >
 >
 >