GMAW Welding Power Digital Supply System Based On DSP Waveform Control

Since GMAW welding with high efficiency, no welding slag, wide application and suitable for all position welding, GMAW was applied more widely in the automotive and manufacturing industry. Low energy input welding that can reduce weld deformation, sufficient penetration and poor appearance of the weld during the welding of thin plate, as a result, the method attracted the attention of a growing number of welding workers. The traditional GMAW can’t weld thinner plate, due to the reason that welding arc heat input and force was inseparable and heat and mass transport was performed at the same time. In order to achieve welding process which stable, precise controllability, the scheme that separated welding arc heat input and force have to be done. This article introduced GMAW welding power supply system based on DSP waveform control. The power supply system matches with the push-pull feeding system precisely and low energy input and little spatter was achieved in the end.By means of the mechanical tension and the appropriate current complete droplet transfer in short-circuits times, the heat input decreased significantly. However, the high quality power supply source and wire feeding machine is needed in push-pull wire feeding system. Push-pull frequency is usually more than50HZ in feeding system. Not only the wire feeding machine with high quality, but also the welding power source with control system fast response time and matching control scheme is needed. The MCS-06C41wire feeder and AC servo driver with high performance was selected in paper, which can obtain higher push-pull frequency. Digital inverter technology appearing, especially DSP was applied in the welding power source control system, makes the response speed of welding power source has been greatly improved, which is more accessible with welding based on push-pull feeding.The hardware system, the software programming with the welding power source and the wire feeding mechanism are introduced in this paper. The hardware system mainly includes DSP (TMS320LF2812) minimum system, sampling circuit, parameter display and preset circuit and protection circuit etc. Special development software Code Composer Studio v4was adopted in the programming. Welding process current waveform, voltage waveform was controlled by software way in various periods, as a result, hardware circuit is more simple, program debugging is convenient and have good adaptability and scalability. The wire movement was set in the actual welding process. The wire feeding process was completed by push-pull wire feeder and constant wire feeder.Finally, some primary welding experiment was done. Through the detection of welding process, the welding results was optimized and analyzed. In this paper, waveform control method is applied to GMAW welding based on push-pull feeding, which has the important research value in reducing the heat input, spatter and welding deformation etc.