Research Of Inverter AC Square-Wave Submerged Arc Welding System

In the preface of this paper, the features, history, present situation of researching of submerged arc welding are introduced; the advantages of soft-switch inverted circuit and differences between analogue circuit controlling system and digital circuit controlling system are analyzed, then indicate that digital controlling is the developing direction of the inverter submerged arc welding. What follows next is the introduction of operating principle and controlling system of submerged arc welding and advantages of AC square SAW, dissertation of theory and impacting reasons of speed-changed wire-feed system, analysis the stability of the welding arc in the situation of speed-changed wire-feed, and these provide theoretical foundation for the design of inverter AC square submerged arc welding system.The digital controlling is the developing direction of the inverter submerged arc welding. This paper employs the MCU+DSP to control the entire welding process exactly. The design strategies and power supplying circle, current and voltage feedback circle, minimized system of controlling chips, communication circle, protecting circle of main board are introduced in detail in the paper. Electromagnetism disturbances can't be avoided in the process of welding machine. Reliability and noise designs are covered in the circles and manufacturing PCB board. Software design is a crucial factor of the stability of welding. In the paper, software design thinking and circuits of controlling system are introduced and several methods are employed to fight the noise.At last, experiments of the controlling system are done in this paper. The results of experiments indicates that the controlling can meet the request of power source and process controlling of SAW. And the controlling system has many advantages such as simple circuit, high control precision, strong anti-interference ability, intelligible dialogue between people and machine and reliable performance. Comprehensive performance of the welding machine and automatic degree are improved.The inverter AC square submerged arc welding source designed by this paper displays the good output characteristic and controlling performance and it can be used for submerged arc welding and hand-arc welding. The power source use the AC square and real time controlling of the entire welding process, then the arc is steady and the quality of welding is good.