Soft-switching PWM full-bridge DC-DC converter with energy recovery transformer and auxiliary passive lossless snubbers

This paper proposes a novel soft-switching full-bridge PWM DC-DC converter using passive regenerative snubber. The newly proposed circuit topology is composed of a full-bridge converter with a high frequency linked transformer and passive snubbers configured with energy regenerative circuit and controlled under the conventional PWM actions to prevent freewheeling current. The leakage inductance of main transformer (Tm) helps to achieve zero current soft-switching (ZCS) turn-on by reduction of turn-on current increasing rate. And the passive lossless snubber capacitor helps to achieve zero voltage soft-switching (ZVS) turn-off. The passive regenerative snubber has the simple circuit configuration and wide operation region of the soft-switching action. The paper indicates the effective converter operation region of the soft-switching action using the theoretical analysis, the design consideration to define the circuit parameters and its efficiency improvement results on the basis of experimental evaluations.