The Current-related Parameter Analysis And The Control To Generate Stable Currents In The Pulsed MIG Welding

The tandem pulsed MIG welding system attracts more and more attention from the field of industrial applications on account of its several advantages,such as high efficiency and fast welding speed.Considering the drawbacks of easy effecting by extra disturbance and deturning of parameters in this system,an improved pulsed-voltage controller based on active disturbance rejection control(ADRC)method is proposed,which is applied to improve the disturbance rejection performance and obtain a better welding capability.The tandem pulsed MIG welding system is mainly composed of the electric load part,arc length variation part and power control part.By building the mathematical model of these three parts separately,the mathematical model of pulsed MIG welding system is obtained.Then,a simulation system using MATLAB/Simulink is built to generate the designed push-pull-type voltage and current.According to the functional relation between pulsed output voltage and electric arc voltage,a traditional proportional integral(PI)controller and an ADRC controller are designed separately.By applying the designed controller to regulate the abovementioned simulation model,the entire tandem pulsed MIG welding simulation system is completed.The comparative simulation results between the PI controller and ADRC controller reveal that the proposed ADRC controller owns a better pulse-voltage generating performance and a stronger disturbance rejection capability.Moreover,the performance to generate pulsed voltage and current under different parameters(various pulsed frequency,various duty cycle,different top voltage reference and low voltage reference)is analyzed.The results prove that the influence from the pulsed frequency and duty cycle is remarkable.Hence,to obtain the best performance,these parameters should be regulated in a certain range.