Current error compensation for current-sensorless power factor corrector stage in continuous conduction mode

A universal digital PFC current-sensorless controller based on control of estimated current is presented. Parasitic elements cause a small difference between the measured input voltage and the voltage across the inductance in a boost converter, which must be taken into account to estimate the input current in a sensorless PFC digital controller. To compensate for the deviation caused by the parasitic elements, and so minimize the current estimation error, the article proposes a digital feedback control technique that cancels the time difference between DCM operation time of the real input current (Tⁱⁿ_DCM) and the estimated current (T^reb_DCM). Experimental results, obtained using a boost PFC converter under different conditions, are shown for verification purposes.