Novel zero-current-switching (ZCS) PWM switch cell minimizing additional conduction loss

This paper proposes a new zero-current-switching (ZCS) pulsewidth modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero-current condition. The diodes commutate softly and the reverse-recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of dc-to-dc PWM converters is derived. The new family of ZCS PWM converters is suitable for the high-power applications employing insulated gate bipolar transistors. Among the new family of dc-to-dc PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5-kW prototype boost converter operating at 40 kHz.