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UCC28050: UCC28050

Stuart Linzer
Intellectual 260 points
Part Number: UCC28050

Hi Group,  

DO-160 specification makes reference to Leading and Lagging Power Factor. 

Does PFC controller like UCC28050 produce a leading or lagging power factor?

Regards, 

Stuart

  • 0
    TI__Genius 10765 points

    Hi Stuart,

    Leading/lagging power factor is primarily the result of the influence of the input filtering (usually "too much" filtering), not the PFC controller itself. The controller is always trying to achieve PF=1, neither leading nor lagging. The filtering which is in place to reduce harmonics can introduce leading/lagging waveforms if not properly designed or compensated, particularly at light load. This can be mitigated (enough to meet specs) by adding an inductor after the bridge while keeping the input capacitance as minimal as possible. Another technique is presented in the attached paper. It uses a technique called LPAC (Leading-Phase Admittance Cancellation) to compensate for current lead by affecting the signal into the controller's error amp. 

    Current phase lead compensation PFC at 500Hz line.pdf

    Regards,

    Ray