Zero voltage soft-commutation PWM DC-DC converter with saturable reactor switch-cascaded diode rectifier

Abstract

An improved single-ended push-pull (SEPP) half-bridge type zero-voltage soft-switching pulse width modulation (ZVS-PWM) DC-DC power converter is presented in this paper, which makes use of a saturable reactor-assisted lossless capacitor type zero voltage soft-switching method. The SEPP power converter with a high-frequency forward and flyback hybrid transformer link has some advantages such as lowered switching and conduction losses, soft-switching transition operation over a wide load range, constant frequency PWM regulation and minimized Electro Magnetic Interference (EMI) as well as Radio Frequency Interference (RFI) noises. Its operating principle is illustrated and its periodic steady-state circuit analysis is implemented. In order to demonstrate the remarkable effectiveness of this converter's characteristics, feasibility experiments are conducted with a 150 W/200 kHz prototype of a high-frequency link ZVS-PWM DC-DC converter using power MOSFETs with an ultrafast soft-recovery diode.