An Integrated High-Power-Factor Converter With ZVS Transition

This paper proposes a single-phase high-power-factor ac/dc converter with soft-switching characteristic. The circuit topology is derived by integrating a boost converter and a buck converter. The boost converter performs the function of power-factor correction to obtain high power factor and low current harmonics at the input line. The buck converter further regulates the dc-link voltage to provide a stable dc output voltage. Without using any active-clamp circuit or snubber circuit, the active switches of the proposed converter can achieve zero-voltage switching-on transition together with high power factor that satisfies the IEC 61000-3-2 standards over a wide load range from 30% to 100% rated power. The steady-state analysis is developed and a design example is provided. A prototype circuit of 60 W was built and tested. Experimental results verify the feasibility of the proposed circuit with satisfactory performance.