hi,

I work with TMEIC CRANE FACTOR + DC source, that uses 8 igbts per phase (4 left and 4 right, parallel connected) and recently 6 of them were exploded immediately when trying to switch on the source power.

It was noticed that the DC out terminals (2 & 3) of the IGBT were severely damaged more than the AC input terminal(1).

Model : Infeneon BSM300GB120DLC

I suspect that a short circuit on DC side have occured and it caused IGBTs to blast.

Any ideas guys?

 

If components are used right at their limits it is not so unsual for them to explode sometimes.

If you use a SMPS it is not a bad idea to have a safety factor, so you could start up large lamps cold without too much worry.

For large power levels, they can't always allow such a big safety factor out of economic reasons.

Some SMPS would contain protection and shutoff circuits or they even might tolerate straight short circuit.

That is by no means guaranteed.

Without knowing your setup (pictures?), it could be anything from a stalled motor, a power surge, or a rodent biting into a cable.

 

here is a pic of the IGBTs, the same way they are mounted on the cooler.
You can see the AC incoming copper bar connected in to pin 01 of each IGBT, so its clear that only pins 2 & 3 are blasted (DC out).

all 4 belong to the same phase and only that phase incurred damage.

cant be rodents since we dont have any,

there are several AC motors mounted to the same DC bus bar which are again invereted in to AC by individual inverters, so if it's a motor stall the 1st to burn is the respective motor inverter IGBT rather than the main DC source IGBT wouldn't it?

here is a schematic of the complete system

 

found the reason! It was due to high humidity and the bus bars flashed over!!

 

thanks for the update!

 

found the reason! It was due to high humidity and the bus bars flashed over!!

No, no, no!

Read this:

http://ksguy.com/site/ml4.html

Especially the right hand column midway down. It's about fuses

 

No, no, no!

Read this:

http://ksguy.com/site/ml4.html

Especially the right hand column midway down. It's about fuses

Haha, very funny.