Synchronous active rectifier-assisted soft-switching PWM DC-DC power converter with high-frequency link

This paper presents a novel prototype topology of soft-switching PWM DC-DC power converter using synchronous active power switches in series with each rectifier diode in high-frequency transformer secondary side. This DC-DC power converter circuit with isolated transformer link, which is suitable for high-power applications, can completely achieve zero-voltage soft-switching under the condition of no freewheeling current operation and wide load variations. Using the proposed soft-switching PWM DC-DC power converter, switching losses of active power devices and their conduction losses are able to be both reduced as compared with the previously-developed soft-switching DC-DC power converter with a phase-sifted PWM in the high-frequency transformer primary side. The steady-state operating characteristics of the proposed power converter circuit and its unique features are illustrated and discussed on the basis of the simulation analysis and some experimental results of 2 kW 40 kHz breadboard.