Modeling of a high resolution DCM times feedback loop for Sensorless Boost PFC stages

The model of the high resolution feedback loop, used in a Sensorless PFC controller for Boost CCM PFC stages is presented is this work. The digital controller used in Boost CCM PFC stages without current sensor produces errors every switching period which are accumulated over the half line cycle, causing a high input current distortion, and consequently a reduction of the power factor. Recent works present a feedback loop that match the DCM times of the actual input current and the estimated one in the digital device. This feedback loop presents a high resolution and achieves a good power factor under universal conditions of input voltage, or wide power range. The models of the plant that obtains the real DCM time and the controller which processes the error between the estimated DCM time and the real one are presented in this work.