A secondary-side phase-shifting ZVS-PWM dual full bridge DC-DC front-end converter for plasma RF power generator

This paper presents a feasibility study of a zero voltage switching (ZVS) PWM dual full bridge (DFB) DC-DC converter with secondary-side phase-shifting power control scheme. The soft-switching PWM DC-DC converter newly-developed for a DC pre-voltage regulator in a plasma radiofrequency (RF) power generator can achieve soft commutation at all the power devices under the wide range of load power. By the phase-shifting control scheme that is based on the secondary-side rectifier of the high-frequency (HF) planar transformer, it can attain the effective reduction of idling power in the primary-side inverter stage. In this paper, the essential experimental data obtained from a 100 kHz-2.5 kW prototype is described to validate the soft-switching circuit scheme and discuss the practical effectiveness of the ZVS-PWM DFB DC-DC converter.