Single‐stage soft‐switched PWM flyback power factor correction with reduced dead angle

This study proposes a single‐stage zero‐voltage transition pulse width modulation (PWM) flybackpower factor correction converter. The bulk capacitor voltage is controlled byusing negative magnetic feedback (NMF) without any input current dead angle. Inthe proposed circuit, the main and auxiliary switches turn on and off underzero‐voltage switching and zero‐current switching conditions, respectively. Theproposed auxiliary circuit provides soft switching condition while eliminatingthe dead angle caused by NMF winding. Thus, high‐efficiency and high‐powerfactor is achieved. Experimental results obtained from a 160 V/300 W circuit areprovided to verify that the proposed structure can suppress the dead angle atzero crossing and soft switching of all switches can be achieved properly.