A New, Soft-Switched, High-Power-Factor Boost Converter with IGBTs

A new soft-switching technique that improves performance of the high-power-factor boost rectifier by reducing switching losses is introduced. The losses are reduced by an active snubber which consists of an inductor, capacitor, rectifier, and an auxiliary switch. Since the boost switch turns off with zero current, this technique is well suited for implementations with insulated-gate bipolar transistors. The reverse-recoveryrelated losses of the rectifier are also reduced by the snubber inductor which is connected in series with the boost switch and the boost rectifier. In addition, the auxiliary switch operates with zero-voltage switching. A complete design procedure and extensive performance evaluation of the proposed active snubber using a 1.2-kW prototype operating from a 90 Vrms-265 Vrms input are also presented.