New high-frequency linked half-bridge softswitching PWM DC-DC converter with input DC rail side active edge resonant snubbers

This study presents a new circuit topology of the active edge resonant snubber-assisted half-bridge soft-switching PWM inverter-type DC-DC high-power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high-frequency PWM inverter with a high-frequency planar transformer link in addition to input DC busline side power semi-conductor switching devices for the PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve zero current switching (ZCS) turn-on and zero voltage switching (ZVS) turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high-switching-frequency isolated gate bipolar transistor (IGBT) can be actually selected in the frequency range of 60-kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of the new converter topology is proved for low-voltage and large-current DC-DC power supplies as DC bus feeding from a practical point of view.