PFC with UCC28180

dirk romeyns

Prodigy 40 points

Other Parts Discussed in Thread: UCC28180

Hello,

i am ussing the UCC28180 for pfc of 500W. The boost coil is 700uH and the switching frequency is 100kHz.

I ussed the excel sheet to calculate the component values

Above 450W the input current is not sine any more.

4520.0000.TIF

Green trace is rectified mains, blue is input current, purple is current in boost coil

Did anyone see this problem?

Solution to this problem?

Thanks

over 11 years ago

0 Lisa Dinwoodie over 11 years ago

TI__Genius 15910 points

At what input line voltage does this occur? The scan looks like it was taken at 230Vac, does it get worse or better if the input line voltage is decreased, and the duty cycle is increased? Can you send a schematic?

0 dirk romeyns over 11 years ago in reply to Lisa Dinwoodie

Prodigy 40 points

Hello Lisa,

please find in annex 2 screenshots of the schematic.

Powerpart

control part

You are correct this is measured at 230VAC.

When i increase the input voltage this phenomenon stays the same

Below picture measured at 265VAC ( measured on transfomer 630VA) load 450W

1754.0001.TIF

Best Regards

Dirk

0 dirk romeyns over 11 years ago in reply to dirk romeyns

Prodigy 40 points

Hello All,

i did some extra measurements and i think the Icomp output is saturating around 6V

Anyone have an idea if this is the cause of the instability?

8080.0002.TIF

Ch1 : output voltage pfc 430V

Ch2 : Icomp pin

Ch3 : inductor current

Ch4 output current 1A/div)

Power management

Power management forum

PFC with UCC28180