blazini36
Newbie level 5
I'm trying to design a self contained DC bus power supply. Specifically it's for a 400v 2200w AC servo drive. Trying to get this all down on 1 PCB for simplicity. I've been using this drive for some time with just 240v mains rectified to 340vDC and some filter caps. The inrush current on charging the caps from flat is rather large, Which for a while I was getting by just upsizing the fuses. I could use the NTC ICL with a contactor bypass controlled externally but like I said I'm trying to get this all down to a PCB with a heatsink and I don't know of any suitable magnetic contactors.
I whipped up a schematic just to put the design down to something I can look at. I'm not very familiar with IGBTs and triacs which is where I need the most help on this. I have 2 triacs in the circuit to cut off the split single phase mains input controlled with gate drivers. There is an NTC on the DC bus side to handle the inrush. Trying to come up with a means of bypassing the ntc after the caps have charged but this is where I'm having the most trouble. I'm not really sure how to derive a suitable voltage or current reference to operate the gate of the IGBT or even if that is the best solution.
There's notes on the drawing for 120/240v input but that'll require a bit more thought so at the moment I'm only concerned with 240v input.
View attachment output.pdf
I whipped up a schematic just to put the design down to something I can look at. I'm not very familiar with IGBTs and triacs which is where I need the most help on this. I have 2 triacs in the circuit to cut off the split single phase mains input controlled with gate drivers. There is an NTC on the DC bus side to handle the inrush. Trying to come up with a means of bypassing the ntc after the caps have charged but this is where I'm having the most trouble. I'm not really sure how to derive a suitable voltage or current reference to operate the gate of the IGBT or even if that is the best solution.
There's notes on the drawing for 120/240v input but that'll require a bit more thought so at the moment I'm only concerned with 240v input.
View attachment output.pdf