View Single Post
Old 03-22-2011, 09:56 PM   #4523 (permalink)
isaac_alaska
EcoModding Apprentice
 
Join Date: Mar 2011
Location: alaska
Posts: 141
Thanks: 10
Thanked 37 Times in 19 Posts
Quote:
Originally Posted by harlequin2 View Post
By the way, if you study the manufacturer's spec sheets, you find that not all IGBTs have a negative temp coefficient. Many of them are almost zero and some are slightly positive and you can parallel those ones very readily. IR have some good app notes on this. I read a lot of them while repairing the LogiSystms thing!
I read this somewhere, i think i might have even posted the findings on here somewhere. one of them was a really good write up on igbts, and i think it included some test examples as well. i do remember that for the most part, NPT type igbt's have a somewhat positive temperature coefficient, and IIRC it actually increases with temperature and current. I'm not too worried about it, as i'm pretty sure that two of them in parallel would be more than enough for my application, i was going to add a third to increase efficiency somewhat by reducing current through each device. Paul is setting me up with the bg2a igbt driver circuit, which takes two vla500 modules. i think that each of them is good for controlling at least two igbt's.

would it be bad practice to use one of the vla500 modules to control 2 igbt's and the other vla500 to control the remaining igbt? or am i trying to make it way bigger than it needs to be, and i should just stick with running two 400 amp igbts?
  Reply With Quote