Originally Posted by Nevyn
So I'm working on our controller using the new and improved controller PCB, the SMD current sensor, and the VLA based IGBT driver from mrbigh.
Here's what we got for IGBTs: 4x Fuji 300A 1200V
Running these IGBT's together would give 1200A. We plan on setting it to 1000A max current.
Based on what Paul said long ago in the main thread:
5% of 1000 is 50A; I'd rather have a little more room for error, so let's say 8% (80A).
Is capacitance tertiary to getting a low ESR and high ripple current rating, or does it matter just as much?
Looking for best as well as least expensive route.
Thank you all!
Sorry im late to the party.
The quote from Paul was interpreted wrong.
"You only need like around 5% of the max current for ripple rating, so they say. 50% is the worst case scenario."
Its 5% of the max current of the worst ripple. The worst ripple is at 50% duty so 500A then take 5% of that. I like to work higher then that in the 25% area, 125A.
Like DJ said, your best bet is to use a bunch of low ESR caps in parallel and throw in some polyester or polypropylene caps for high current rating. But be careful for ringing.
What voltage do you plan on running with these IGBT's?