Abstract:

In order to analyze the stability of welding arc and control the quality of submerged arc welding, this paper establishes a dynamic model to describe the burning of arc and the feeding of wire during the welding process. By using the welding arc as a feedback parameter, a linear proportional circuit and a Buck DC/DC converter are combined to form a mechatronic closed loop. The Buck DC/DC converter as the power supply for wire feeder is modulated via pulse-width modulation, and the closed loop as the fundament of system control is described by a differential equation. Moreover, a hybrid time constant considering the wire feeder, the welding arc and the electronic control circuit is presented as the major parameter reflecting the adjustment rate of the system. Analytical results show that, whatever the initial value is, the welding arc voltage Uare would reach a set value.

Key words: submerged arc welding, mechatronics, dynamic model