The Study of Welding Power-Arc System Stability Based on DFCD

Regarding welding power-arc system stability (WPSS) as the research object, the paper uses differential theory and considers the full load conditions from the external circuit on the course of dynamic welding, and some models about WPSS are found, they can obtain the analytic expression of system stability coefficient, and a qualitative analysis of WPSS' conditions is so born, on this basis, by the method of the relative conversion of current deviation, a dynamic factor of current deviation (DFCD) is obtained by analytical equation，then to quantify stability of the system by the way of decay time of deviation. Test's results, based on analysis of voltage and current waveforms, are the same to quantify the WPSS based on DFCD.