Control System Based On Dsp Inverter Dc Welding Machine

The welding arc is a kind of complex load and the electric specification of welding source must adapt its characteristic. In order to meet the new craft of arc welding, we must research a new welding power source to correspond arc electrical specification. Welding inverter that works at the frequency between 20 K to 100 KHz has a much less volume and weight, and it is the base of precise control of welding inverter.Because analog circuit is widely adopted in welding inverter control, the control precision in output amplitude value is little enhanced. The research presented here is concentrating on digital control of welding inverter, aiming at enhancing control precision and flexibility. Starting from analyzing the requirements of electric arc for electrical characteristics of arc welding power source, the paper puts forward the totality plan and the designing principles of the control system. In this system, the core control chip is TMS320LF2407, produced by TI Company. Its formidable date-handling capacity, the high speed (40MHz), the high precision (16bits), and adding the strong control characteristic of SCM, which have provide the ability to realize the digital control system of welding inverter power source. In this paper, some primary parts of welding inverter power source are designed. We established a Matlab model for welding inverter. With this Matlab model we simulate the working processes of welding inverter and digital controller predicted the control precision and effect. Welding inverter external characteristic and dynamic characteristic are also simulated and analyzed in this dissertation. In the control arithmetic, the digital PID algorithm is adopted. The simulation model is established about PID algorithm, credible and applied parameters are provided.