A Novel High-Frequency Transformer Linked Soft-Switching Pulse Modulation DC-DC Power Supply for Arc Welder

摘要

This paper presents a new circuit topology of DC bus line switch-assisted full-bridge soft-switching PWM inverter type DC-DC converter for arc welder. The proposed power converter is composed of typical voltage source H full-bridge high frequency PWM inverter with a high frequency transformer link in addition to a single DC bus line side power semiconductor switching device for PWM control scheme and a capacitive lossless snubber. All the active power switches in the full-bridge arms and DC bus line can achieve ZVS/ZVT turn-off commutation operation and consequently the total turn-off switching losses can be significantly reduced. As a result, a high switching frequency of using IGBTs can be actually selected more than about 10 kHz. The effectiveness of this new converter topology is proved for low voltage and large current DC-DC power supplies such as arc welder from a practical point of views.