Re: Please help ! IGBT exploded ...

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

Original poster: Sean Taylor <sstaylor-at-uiuc.edu> 

IGBTs will tend to be a lot slower than FETs - and have a lot higher gate 
capacitance.  I'm guessing you had shoot through, and the immense current 
blew the IGBTs.  ALWAYS ALWAYS do low voltage testing before applying the 
full voltage - use a variac and monitor the input current, or run from a 12 
VDC source first and check all the waveforms - see if the output devices 
have the right gate waveforms, and are in fact turning on and off at the 
right times.

If you'd like, I'll post a schematic for a simple deat time controller so 
that you can add a small amount of "off" time in between pulses while 
waiting for the IGBTs to turn off.

Sean Taylor
Urbana, IL

On Mon, 08 Mar 2004 07:45:01 -0700, Tesla list <tesla-at-pupman-dot-com> wrote:

>Original poster: "Rajesh Seenivasan" <rajeshkvs-at-hotmail-dot-com> Dear forum 
>members,
>
>Yesterday I was experimenting with an old IGBT - BSM100GB60DLC, which I 
>got from my friend,
>for my SSTC. I used the same gate driver I designed for IRFP460 MOSFET H 
>bridge.
>I connected the terminals to 220V line and neutral and switched ON my gate 
>drive circuit.
>The IGBT exploded immediately ! I did not give any load to IGBT. The H 
>Bridge's
>output terminals were not connected to anything !
>The gate drive was at 70kHz approx.
>I observed that the gate drive waveform was not clean like a square wave.
>Any advise for me ?
>
>