새로운 소프트스위칭 3레벨 Flying Capacitor 컨버터

This study proposes a new soft-switching three-level flying capacitor converter with low filter inductance. The proposed converter can achieve zero voltage switching (ZVS) turn-on of all switches by using auxiliary components La and Ca. It can also reduce filter inductance because the applied voltage of the filter inductor is decreased by using the flying capacitor. Furthermore, filter inductance can be reduced because the operating frequency of the filter inductor is doubled by the phase shifting between switches S3 and S4. The operation principle, design of passive components for ZVS turn-on, interleaving effects, and comparison of different topologies are presented. The experimental waveforms of a 1 kW two-phase interleaved converter prototype are provided to verify the validity of the proposed converter.