Quote:
Originally Posted by squiggles
I have not seen the start of this discussion but it looks to me as though each of your IGBT will have to be rated for full motor current.....unless they are overlapping then the first that come on has to handle full current.
I am not seeing what the advantage would be?
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I agree. Better would be to have all the IGBT's share the load. However, to do that you have to derate the max current each can carry because they will share unequally based on structure, temp, and gate characteristics. In short 4 400A IGBTs cannot carry 1600A.
A good paper on the subject is the Dynex application note AN5505. You can find it here:
Application Notes - Power - IGBT
Rules of thumb:
1) Derate the max current.
2) Use individual gate resistors for each module.
3) Put all the modules on the same heat sink.
4) If you cannot match the modules, then put a load sharing resistance on the emitters of each module.
ga2500ev