I have found this PFC controller (I am building a rectifier to ~500V). As I understand, because PFC uses a boost converter, it should be able to boost rectified voltage to bigger voltage. How would I set this voltage? Do PFC controllers have such ability? Or do they just make output ~325V (from 230V AC)?
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1\$\begingroup\$ Designers usually select a boosted voltage slightly above the maximum peak value of the input line. This is because the less you boost, the best the efficiency. Therefore, if your mains is 265 V rms as a max, it is not uncommon to find regulated voltages at 380 V dc for instance, 400 V being a maximum. Also, some designs include a boost follower mode where the regulated dc voltage changes with the input voltage, again to maximize efficiency: 250 V dc from 85 to 150 V rms and 380-400 V beyond. Some circuits do that automatically, some externally by altering the resistive division ratio. \$\endgroup\$– Verbal KintCommented Nov 27, 2022 at 11:09
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\$\begingroup\$ On top of what @VerbalKint said, electrolytic capacitors peak at 400 V (price/performance), so going above 400 V DC for a 85-265 V AC input device becomes suboptimal. \$\endgroup\$– winnyCommented Nov 27, 2022 at 11:22
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\$\begingroup\$ Also - could PFC controllers deal with not perfect sinusoidal input? If it is in poor quality (amplitude top is chopped by other non-PFC rectifiers)? \$\endgroup\$– Ri DiCommented Nov 27, 2022 at 19:15
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How would I set this voltage?
Your device can modify the boosted value by adjusting the resistor ratio in red: -
The set voltage has to be larger than the peak AC voltage else you won't get a pseudo-resistive current being drawn from the AC line.
Do PFC controllers have such ability?
I'm not saying that all PF controllers are like this (because that would be an exhaustive study). However, most that I have seen have this ability.
answered Nov 27, 2022 at 10:59