Isolated quasi z-source bridgeless power factor correction with coupled inductor

Existence of slow-recovery diodes on conduction paths of the isolated power factor correction converters causes conduction losses. This study proposes a new topology for PFC applications, namely isolated quasi z-source bridgeless PFC converter, to improve efficiency by eliminating of the low-recovery diodes on the conduction paths. The voltage spikes on MOSFETs caused by resonance between parasitic components are completely absorbed by using a non-dissipative clamping structure. As a result, low-voltage MOSFETs with low R_ds(ON) are used to reduce the conduction loss. Moreover, couple-inductor is utilized to reduce the size of the boost-inductor. In this paper, a simulation circuit with 180-240 V input, 400 V/1 kW output was verified to demonstrate its feasibility. The simulation results shown the spikes on MOSFETs were absolutely eliminated. The input current was sinusoidal and in phase with the input voltage. The proposed topology is promising for high efficiency, high power factor, and low current total harmonic distortion applications.