Research Of Digital Arc-welding Power Source Based On DSP Control

As the development of technology, it becomes more and more important for arc welding technology in the use of moderm industry. Arc welding power supply is the key part of electric welding machine, so its performance directly affects the welding quality. Digital invert arc welding power supply has become the main developing aspect of welding power supply because of its advantages such as good welding performance, quick dynamic respond, small cubage, light weight, high efficiency and intelligent control.Main circuit, which applies IGBT full-bridge inverter structure with its frequency of 20 KHz, is made up of rectifier, filter, medium-frequency transformer and output reactance. The key points and parameters of the design are discussed in this article.In the digital control system of the welding power supply, the chip TMS320F2812 as CPU, it has high speed and precision, and provides the ability to realize the digital control system. Under the action of main modules: DSP minimize system , voltage and current real time sampling module and protect module, parameters presetting and display module ,real time close loop control and real time protect of the welding power is applied. Using universal PWM method means to control output power and output characteristic through controlling IGBT switch on time. The system real time sample output current and welding Voltage, and use PID control algorithm realize the purpose of control output characteristics of welding power.This paper also expounds the resource distribution and the function of outer circuits. Aim to typical problems in welding process, including over voltage, lack voltage, over current, over heat, corresponding protection circuit are designed.For the main circuit and control circuit in the paper, we construct the simulated model through Matlab/Simulink tools, And gives the simulation waveforms of arc welding power source load, An analysis of the waveform. Final, it is analysis and design with the reliability and anti-jamming measures of the control system, it is taken by the hardware anti-jamming measures and Software anti-jammingtechnology in the relevant circuit.