A full-bridge ZVS converter applied to high power millimeter-wave gyrotron travelling wave tubes

摘要

This paper presents the design of a phase-shifted full-bridge converter, a zero-voltage switching (ZVS) and pulse-width-modulation (PWM) dc-dc converter with phase-shifting power control scheme. The ZVS-PWM dc-dc converter treated here can achieve soft commutation in all the power devices under the wide range of output power variation. For this purpose, an auxiliary resonant circuit is employed to minimize conduction losses while maintaining soft-switching characteristics in the IGBTs. As a result, the proposed combined techniques successfully reduce conduction losses, minimize reverse-recovery losses in the output rectifiers, minimize transformer ringing, and ensure low stress in all the switches. A 20-kHz/60-kW prototype is implemented. Experimental results are presented to validate the efficiency gains, illustrate the benefits of the modulation, and demonstrate the soft-switching transitions.