RE: Please help ! IGBT exploded ...

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

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

 >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

I agree, 5V is way too low. Even 10V isn't really enough IMO. I use at least
15V in all my IGBT stuff, some I drive up to 25-30V to try and squeeze more
current out of them. And a faster gate driver probably would help.

It does sound like you killed it by shoot-through. Older "First-generation"
IGBTs can take more than 1 microsecond to turn off after the gate drive is
removed. 1us is 14% deadtime at 66kHz so I would use that much at least.

To get the deadtime to work you must drive your GDT primary with a
full-bridge of two gate driver chips, each fed from one output of the TL494.
This allows the driver chips to short the GDT primary during the deadtime
periods, forcing the voltage to zero and turning both IGBTs off.

Steve C.