The Research Of CO₂ Digitization Welding Inverter

With the development of power electronic technology, the achievement of high-speed digital signals technology and modern control technology, digitization welding inverter comes true.The research presented here is concentrating on the CO₂ welding.In this article, welding theory and welding process is deeply analyzed,then the digitization welding inverter design scheme basing on CO₂ short circuiting arc welding is brought forward,the circuit is design,at last welding control process and control arithmetic is analyzed.Too much spatter and bad-welding bead are the two cirtical problems in CO₂ short circuiting arc welding process.To solve these two problems,an inductance is connected in the output loop of constant voltage characteristic power source in the conventional SCR welding inverter.However,there are different welding characteristics at different welding parameters,which cannot be solved to a satisfying degree.In this article,these methods are used to improve system performance and reduce welding spatter:using IGBT full bridge structure circuit as power curcuit of CO₂ welding system,DSP chip as hardcore of control curcuit,DIP control whose parameters is chosen appropriately as welding control arithmetic.In this paper,at first welding theory and welding static and dynamic charaters is discussed,and the problem and cause of spatter in CO₂ short circuiting arc welding is deeply analyzed.Then, the digitization welding inverter general hardware design scheme is brought forward,meanwhile power transfer circuit,DSP control circuit and peripheral circuits including PWM transfer circuit,current and voltage reactive circuit are designed.At last,the physical model of CO₂ welding is analyzed,and the controling method of CO₂ short circuiting arc welding's current and voltage by using PID control theory.The digitization CO₂ welding inverter is probed in this paper,which provides the foundation of advanced research on wielding robot.