为提高大功率双丝熔化极气体保护焊( GMAW) 的焊缝成形质量，提出了双脉冲波形控制方法，利用DSP 内部集成的脉宽调制( PWM) 模块，以软件方式实现了并联式主从机PWM 信号的直接数字化控制，从而实现主从机的双脉冲波形调制． 利用DSP 的I /O通信方式建立双脉冲多相位协同控制系统，实现大功率双丝GMAW 两路脉冲同步、交替和独立3 种输出形式的协同控制． 试验结果表明: 所设计的双脉冲多相位协同控制系统满足设计要求，焊接过程稳定，双电弧干扰小，飞溅小，焊缝成形良好，双脉冲焊缝表面呈鱼鳞状，能很好地实现大功率双丝GMAW 工艺．

In order to improve the forming quality of welding seam during the high-power twin-wire GMAW ( Gas Metal Arc Welding) ,a double-pulse waveform control method is proposed.The proposed method adopts the PWM ( Pulse Width Modulation) modules integrated in DSP ( Digital Signal Processor) to implement the direct digital control of PWM signals for the parallel master and the slave power supply in a software mode,so that the corresponding double-pulse waveform modulation is further achieved.Moreover,a double-pulse multi-phase coordinative control system is developed by using the I /O communication of DSP,and the coordinative control of synchronous,alternate and independent phase outputs of two pulses for high-power twin-wire GMAW is realized.Test results demonstrate that the developed double-pulse multi-phase coordinative control system meets the design requirements well and helps to achieve stable welding with decreased twin-arc interference,little splash and perfect welding seam with scaly appearance.