Research On Soft-Switching Digital Welding Power Source Based On DSP

Through a brief introduction on the present state and development of the welding inverter, this paper analysis the drawbacks of the welding machine and blurts out the meaning of researches the digital characteristics of the welding power supply dand the main circuit of the full bridge high power soft-switching.This paper researches the digital characteristics of the welding power supplyand the main circuit of the full bridge high power soft-switching. First of all, by the theory of the soft-switching, this paper relatively analysis the advantages of the soft-switching and, with the help of the simulation software SWCADâ…¢, analyzes the main circuit of the full bridge shift-phased zero voltage zero current(ZVZCS) soft-switching. Then, the paper gives the on and off theory of the soft-switching, the model of the main circuit, the key point and the parameters of the design.Welding power supply is a key point of a welding machine. The disadvantages of the traditional analogue control circuit have become a blur of the welding power supply. Because of its excellent performance, this paper applies the up-to-date control chip TMS320F2812, which is producted by the American TI(Texas Instrument) company. The TMS320F2812. The control core of the welding power supply outputs four pulses waveform, which is different from each other of their phase position. After the magnifying of the drive module, the output waveform can drive the IGBT and control the on and off of the power device IGBT TX-KA962. Hall sensor samples welding current in real time, and changes the current to the voltage of zero to 3V, which is supported by the TMS320F2812 DSP, and then feedbacks to the AD input of the TMS320F2812, by the PI control algorithm, realize the aim of the control output constant current characteristics of the welding power source. The result is verified by experiment and the power source based on the DSP can meet the need of the welding process.