A general three-phase PFC controller. I. For rectifiers with aparallel-connected dual boost topology

摘要

A general constant-frequency power-factor-correction (PFC)controller is proposed for three-phase rectifiers withparallel-connected dual-boost topologies. This paper shows that unityfundamental power factor and low current distortion in all three phasescan be realized by one-cycle control of a linear combination of theinductor currents using one integrator with reset along with a few logiccomponents. This new extension of one-cycle control provides the corePFC function to the dual-boost topologies and the logical circuitrotates the PFC function in three phases. It does not requiremultipliers, used in many other control approaches, to scale the currentreference according to the output power level. In each 60° of ACline cycle, only two switches are switched at high frequency; thereforethe switching losses are significantly reduced. All switches areswitched at low current, which results in reduced current ratings. Thiscontrol method is simple and general. It is applicable to three-phaserectifiers that can be decoupled into parallel-connected dual-boosttopologies by slight modification of the logic circuit. This controlmethod is verified by theoretical analysis and experimental results. Theproposed controller is ready to be integrated into a three-phase PFCcontrol chip