Good Day All:
We have designed a digitally controlled, 2-4-6 phase boost regulator. Our output power requirement is configured in 2KW chunks up to 6KW. The output voltage has a control range of 400 - 800 VDC. Each boost controller has digitally variable current draw, VAC gain, Rsynth and multiplier output. Each stage is externally clocked/synced as they are added. The switching frequency is 50khz as I am using IGBT's due to the higher bank voltage. The output capacitor bank is 7700 uf at 900 VDC rating. This weird cap value is needed for our load. Our mains voltage range is 180-265 VAC 50-60 Hz.
Question:
1. I am pleased with the UCC28070 in our application. Our load is a big pulse discharge that effectively causes the boost current to hit the PKLMT for a couple cycles. Works great. The question I have is the value of Vinac relative to output voltage. Note 1 from sheet 28 of the 28070 spec is highlighted below and I am a bit uncertain of its meaning. I would like any opinions on the exact meaning of note 1 and what the Vinac value should be as output voltage changes from 400 - 800. The power system is controlled by an Altera FPGA and I have lots of resources for control functions, realtime math, ROM table values or whatever.
Thanks in Advance
Ralph Saunders
