IGBT damage while discharging a capacitor

[Learning_goal]

I am working on a circuit which discharges a capacitor charged to around 400 volts using a IGBT (acting as a switch) through a soleniod coil connected to a plunger to dissipate energy mechanically. The IGBT used is FGA25n 120. L293D motordriver is used with a microcontroller to provide gate voltage of 12 volts whenever microcontroller gives high to the L293D. When I tested the circuit for charge of 170 volts and it worked fine, but for 300 volts the IGBT got damaged.I'm unable to figure out the reasons, please help me to know the possible reasons.

 

[FvM]

Generally speaking, we would expect an exceeding of maximum ratings. E.g. unwanted multiple switching during capacitor discharge can create high overvoltage. For a detailed discussion, all circuit parameters must be known, also the circuit geometry to understand if uncontrolled switching is a likely issue.

 

[engineerpervez1]

I think you have to use some proper snubber circuit to suppress the high spikes (fly back voltage) generated when igbt switched off.
see the link below
www.cde.com/tech/design.pdf
Also many IGBT are protected with some Shotky diodes connected across its emitter and collector. I have no idea the one you are using is has one.
As a thumb rule if you are in a range 220 volts AC(+320 volts DC) you must use a IGBT of 600 volts rating.
or if your range is 400 volts Ac(+580 volts dc) you should use atleast 1200 volts rating IGBT