PWM converter-inverter arc welding machine using new type NCT

The inverter circuit has been adopted to welding machines to improve welding performance. As the conventional inverter welding machine has a diode rectifier, there are many problems such as input current harmonics generation and low power factor, which can be solved by the high power factor inverter arc welding machine proposed. The characteristics of new type noise cut transformer is investigated, which could prevent switching devices from being destroyed by electrical noise generated from arc welding procedure. The experimental results are shown from the view point of welding performances and power factor. Through the experimental results the welding performances such as spatter and bead are greatly improved and the power factor is maintained roughly to unity.