A Flexible Input Currents Control Strategy for Three-Phase PFC Rectifier under Unbalanced System

Power factor correction (PFC) rectifiers are essential for load side harmonic and reactive power correction. In recent years, research and applications of PFC rectifiers have attracted more attention due to the increased energy awareness in the global. The new three-phase boost PFC rectifier which is based on one cycle control and proposed by Chongming Qiao is featuring excellent performance, simple circuitry, and low cost, and under balanced or unbalanced source, the input currents being kept low harmonic and linearly proportional to the non-zero sequence of the three-phase input voltages. But C. Qiao´s control strategy has shortcoming to control input currents flexibly under unbalanced source, for example, to minimize output filter, we want to control the input currents such that the input power is a constant, or we want to control the input currents keeping balanced, or we want the input currents fully in-phase with each own voltages. This paper improves the control strategy and introduces a new general current control equation which can control the input currents flexibly. By selecting different current control parameters (CCP), we can achieve four control goals: (1) the same method which has been described in literature; (2) input currents fully in-phase with its own input voltages; (3) constant input power; (4) balanced input currents. Experimental results are presented to verify the theoretical analysis