A New High Frequency Linked Soft-Switching PWM DC-DC Converter with High and Low Side DC Rail Active Edge Resonant Snubbers for High Performance Arc Welder

This paper presents a new circuit topology of active edge resonant snubbers 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 typical voltage source fed half-bridge high frequency PWM inverter with a high frequency transformer planar link in addition to dc busline side power semiconductor switching devices for 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 dc buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions and consequently the total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the range of 60 kHz under the principle of soft switching. The performance evaluations of the setup are illustrated experimentally. The effectiveness of this new converter topology is proved for low voltage and large current dc-dc power supplies such as DC bus feeding from a practical point of view