An electronic welder control circuit

This paper presents a 6 kW electronic welder control circuit. The DC welding current is controlled with a simple and robust control circuit. Fast dynamic performance and low current ripple are achieved. Paralleled IGBTs are used with a switching frequency of 50 kHz. The welder machine with this control stage can be applied to shielded metal arc welding and gas tungsten arc welding processes. The welding DC voltage is also controlled with an outer controller acting in the current reference value. Fast dynamic is also obtained for the DC voltage control without steady state error. With this control level, gas metal arc welding and flux-cored arc welding can be applied. The current control and the DC voltage control can also be applied in different cycles depending on a external signal. In the peak and background current cycles. the current control and DC voltage control are applied, respectively, enabling the use of the electronic welder for pulsed gas metal arc welding. In the paper, the system modelling is also realised. Some modelling and experimental results are presented. The annoying problems caused by this type of equipment in low voltage networks are also shown.