Bridgeless power factor correction circuit

摘要

The present invention provides a bridgeless PFC circuit. A low-frequency bridge leg includes two diodes connected in series: a first diode and a second diode; a three-port network includes a switch tube and an inductor, and the low-frequency bridge leg and the three-port network act together to realize PFC; a lightning and surge protection bridge leg includes two diodes connected in series: a third diode and a fourth diode; a capacitor is connected between both terminals of the low-frequency bridge leg, and between both terminals of the lightning and surge protection bridge leg; a common terminal of the first and second diodes is connected to a terminal of an AC power, and a common terminal of the third and fourth diodes is connected to the other terminal of the AC power; and the three-port network has a first port and a second port with the capacitor connected therebetween, and a third port connected to the common terminal of the third and fourth diodes. By using a lightning and surge protection bridge leg including two diodes connected in series for lightning and surge protection, EMI performance can be improved, costs of the whole circuit can be lowered and efficiency can be improved.