Study and implementation of a single-stage three-phase AC-DC converter

A single-stage three-phase AC-DC converter is presented in this paper. The front semi-stage of the proposed converter, which is operated in discontinuous conduction mode (DCM), is utilized for power factor correction and the rear semi-stage of the proposed converter, which is operated in continuous conduction mode (CCM) at heavy loads and in DCM at light loads, is employed for step-down voltage conversion. The proposed converter can achieve almost unity power factor, low total harmonic distortion of input current (THD_i), and adjustable DC output voltage. The voltage stress across the DC-link capacitor is low. Moreover, the steady-state analyses of voltage gain and the boundary operating condition are discussed. Finally, experimental results are provided to verify theoretical analyses.