Hello
This is 12kw UPS board, 3 phase, as you see there is 5 capacitors in parallel and each two are series together
I've checked the board for blown igbt and doide, and found the igbt is 75n65fl2, 75 ampere and 650v, we have the igbt, but not the doide and we're looking for replacement one
The doide is MM60fu120B, which is 60 ampere and 1200v, my question is that can I use lower voltage doide?, for example 600v?,
The capacitors are 450v rated which means that voltage at the capacitors can not exceed the 450v, if 2 series capacitors, the voltage can be higher at the negative and positive terminals of DC bus at those capacitors?, if so how much can be?, as estimation?
The batteries are 20 battery 12v which is 240v DC on series
Can we calculate the DC bus voltage so we estimate the voltage on the inverter circuit?, or estimate the voltage at the igbt and doide? according to the capacitors configuration?
Assuming the inverter is T-shape inverter and circuit similar to this