Hybrid soft switching DC-DC boost converter

In this study, hybrid soft switching (HSS) DC-DC boost converter is proposed. The proposed converter operates as the conventional discontinuous conduction mode (DCM) pulse-width modulated (PWM) DC-DC boost converter at light loads. When the output power increases, the snubber cell is activated, and the converter operates as frequency controlled soft switching resonant converter. Thus, higher efficiency is obtained at high power levels. In the proposed converter, the snubber cell works with a simple on-off logic instead of PWM control. Thus, it has a quite simple structure consisting of only a switch and a snubber capacitor, and does not need an additional PWM control signal. Hence, the proposed converter has the advantages of conventional DCM PWM converters while operating with higher efficiency at higher power levels. There is no additional voltage stress on any semiconductor power devices. Theoretical analysis is verified with a laboratory application of a DC-DC boost converter having input voltage of 90 V, output voltage of 400 V and output power of 1 kW.