Analysis of a high step-down AC-DC converter

A high power factor and high step down AC-DC converter is presented in this paper. The front semi-stage of the proposed converter is a modified AC-DC buck-boost converter. This semi-stage is operated in discontinuous conduction mode to achieve high power factor and low total harmonic distortion of input current. The rear semi-stage of the proposed converter is a high step-down DC-DC converter. The voltage stresses of the power devices in the proposed converter are low. Also, the DC-link voltage in the proposed converter is lower than the peak value of the input voltage. The steady-state analysis is discussed. Finally, a simulation is done to verify the performance of the proposed converter.