Advanced High Power DC-DC Converter using Novel Type Half-Bridge Soft Switching PWM Inverter with High Frequency Transformer for Arc Welder

This paper presents a new circuit topology of DC bus line switch-assisted half-bridge soft switching PWM inverter type DC-DC converter for arc welder. The proposed power converter is composed of typical voltage source half-bridge high frequency PWM inverter with a high frequency transformer link in addition to DC bus line side power semiconductor switching devices for PWM control scheme and capacitive lossless snubbers. All the active power switches in the half-bridge arm and DC bus lines can achieve ZCS turn-on and ZVS 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 view