1-kW PFC converter with compound active-clamping

A PFC converter employing compound active clamping technique is proposed. It can effectively reduce the loss caused by diode reverse recovery. Both the main switch and the auxiliary switch can achieve soft-switching (ZVS) under certain conditions. The parasitic oscillation caused by the parasitic capacitance of the boost diode is eliminated. The voltage on the main switch, the auxiliary switch and the boost diode are clamped. The principle of operation and theoretical analysis are presented. The maximum voltage stress of switches and the soft-switching region with relation to the resonant inductor and resonant capacitance are investigated. A prototype of 1kW is built to test the proposed topology. The input voltage is from 90V_rms to 265V_rms. The output voltage is 380V. The operation frequency is 100 kHz. The measured efficiency at full load with different input voltage is from 93.5% to 97.8%.