filter capacitor in invertor welding machine

[deepaknarkhede]

dear all,

I consrtucted Invertor welding machine 400A with filter capacitor 50MFD in DC link.
Some machine of same capacity uses 470MFD. I find large variations. How exactly it affects
the performance, can I use 25MFD for 250A machine?

deepak

 

[FvM]

There are several aspects determining the capacitor selection:

- 1 or 3 phase input
- accpeptable DC bus ripple voltage
- capacitor AC current rating

designing an inverter should include a calculation of capacitor parameters, I think

 

[deepaknarkhede]

There are several aspects determining the capacitor selection:

- 1 or 3 phase input
- accpeptable DC bus ripple voltage
- capacitor AC current rating

designing an inverter should include a calculation of capacitor parameters, I think

Thanks.
I dindt say I designed, I just copied. Thats why the question raised. The machine is three phase
and being welding machine as far as output is concern, it can accept any level of ripples. Only
it should be acceptable to IGBT and its firing. Will it affect temperature rise or if filter has to do with output ripples only, then I could remove it totally.
pl guide

deepak