Unified constant-frequency integration control of three-phase standard bridge boost rectifier

In this paper, a three-phase six-switch standard boost rectifier with unity-power-factor-correction is investigated. A general equation is derived that relates input phase voltage and duty ratios of switches in continuous conduction mode. Based on one of solutions and using one-cycle control, a unified constant-frequency integration (UCI) controller for power-factor-correction (PFC) is proposed. For the standard bridge boost rectifier, unity-power-factor and low total-harmonic distortion (THD) can be realized in all three phases with a simple circuit that is composed of one integrator with reset along with several flips-flops, comparators, and some logic and linear components. It does not require multipliers and three-phase voltage sensors, which are used in many other control approaches. In addition, it employs constant switching frequency modulation that is desirable for industrial applications. The proposed control approach is simple and reliable. Theoretical analysis is verified by simulation and experimental results