I am repairing a UPS system which inverter IGBT using 2MBI150N-120 (150A 1200V) was found faulty,and I just have 2MBI150N-060(150A 600V) in stock,do you think that I can use 2MBI150N-060 instead of 2MBI150N-120?The DC rectifier Voltage produced to the IGBT pins C1 & E2 is just 435Vdc.Thanks!!!!

 

I'd try it. It may not have as great a mean time between failure in your application.

Do you know why the N-120 failed?

 

May be ok but check the circuit for other problems first and realize the part you're sticking in is lower rated. How expensive are those?

http://www2.scut.edu.cn/scutco/main...tasheets/igbt/N-series/1200V/2MBI150N-120.pdf
http://www2.scut.edu.cn/scutco/main...atasheets/igbt/N-series/600V/2MBI150N-060.pdf

 

http://bbs.home.news.cn/upfiles/03437EE5.002C

Pls refer to this circuit.This is the circuit for the UPS inverter o/p,if I put 2 different brand IGBT,Q1(brand A)&Q2 (brand B).both 1200Vdc 150A,don't
know it works or not?

 

The BRAND of IGBT's you use shouldn't really make much of a difference, as long as they meet the specifications required.

If you replace an original part with one of lesser specifications, it may not last - or may not work at all before letting the smoke out.

I would check that output transformer carefully to make sure there is nothing wrong with it.

Make sure that your heat sinks are installed properly, free from corrosion/contamination, and that you use heat sink compound.

 

Those two parts are not the same size... the 1200V is larger and handles more power. 600V is not much margin above 453V even for this topology SMPS. I do not see any snubber across the IGBT. I'd verify the control to the IGBTs is functioning properly since a malfunction would definitely "let the smoke out" as was mentioned earlier.

 

Also check C1 to insure there is no shoot-through, and check any load as well. The original IGBTs may have failed due to a reflected short.