Hello,
We are developing a 5kW AC-DC power supply with the UCC28950 as the controller. I have a problem that I am unable to root cause. I am hoping to find a ready solution here.
1) In Peak Current Control, the C-D FETs fail with no apparent reasons. The failures can happen at almost any loading conditions (DC Bus is fixed at 400V).
2) Unable to solve the above, we proceeded with Voltage Mode Control after adding a series capacitor to the inverter (to prevent transformer saturation). The hardware works fine till we hit the peak inverter current limits. The C-D FETs fail again!
The inverter current is sensed using a CT, rectified and fed to the CS pin via a RC filter as described.
3) C-D would be the "Leading FET" drives right? I was told by another engineer that A-B could be the Leading FETs.
Any quick available solutions/ideas will be helpful. Thank you and have a good day,
- IATOME>