Development Of A Three Phase Single-stage PFC Rectifier

Power factor correction(PFC)technology is an effective way to suppress current harmonics and improve power factor.In medium and high power applications,compared with the traditional three-phase two-stage PFC technology,three-phase single-stage PFC technology has the advantages of simple structure,high power density and high efficiency,etc.It has been an important research aspect in the field of power electronics.A three-phase single-stage PFC rectifier based on isolated Boost full-bridge converter is proposed and studied in this paper.Following introduce the power factor correction mechanism and control strategy of the circuit topology.By contrastive analysis,an LC resonant snubber circuit aimed at solving the bus voltage spike caused by leakage inductance of transformer in this topology is introduced.Then,by presenting the working principle of the snubber circuit in detail and reestablishing the equivalent circuit model of the circuit topology at the formation of the bus voltage peak,the snubber circuit parameters can be designed from perspectives of both restraining the bus voltage spike and reducing the wastage.A three-phase rectifier prototype of 3kW has been built and tested in the lab.The experimental results verify the feasibility of this topology for power factor correction and the significance of LC resonant snubber circuit to suppress the bus voltage spike.Through loss analysis,an improvement proposal to improve the efficiency of converter can be provided.