Development of Digitally Controlled SCR Arc Welding Power Source with the Dual-step Characteristics

摘要

In this paper, the main circuit of the SCR arc welding power source with balance reactor of doublernreversed star connection is designed. According to the principle of optimality, the main transformer which isrnlight in weight ,cheap in cost and energy saving is manufactured. With the SCR arc welding power sourcernbased on the 8031 single chip microcomputer being in use, the hardware and software of the control system arerndeveloped. Welding voltage and welding current negative feedback is adopted in the control system in order tornrealize the dual-step static characteristics of the SCR arc welding power source. The digital PID algorithm isrnadopted in the control system with both static and dynamic characteristics take into consideration. Interferencernis avoided by means of software and hardware. The static characteristics are tested and welding technologyrnexperiment of manual metal arc welding and automatic submerged arc welding are carried out . The resultsrnshow that the arc welding power source designed can be used in the manual metal arc welding and submergedrnarc welding and has realized the dual-step characteristics. The power source is multifunctional and achievesrnthe expected goal in the reliability and stability.