中文摘要：

针对现有开关电源的动特性限制,难以实现高频（≥20 kHz）脉冲电流输出.采用新型主电路拓扑结构,辅以DSP（数字信号处理器）和CPLD（复杂可编程逻辑器件）为控制核心的数字化控制系统,研制了数字控制复合型高频脉冲TIG焊接系统.设计有效的时序控制方案和电源外特性控制方案并配合切实有效的控制算法及保护电路,实现了与现有TIG焊工艺过程的有效复合,可进行稳定的高频焊接.结果表明,复合型高频脉冲TIG焊具有良好的工艺特性,表现为铝合金焊缝熔合线两侧的气孔显著减少,并在熔合线母材侧形成明显细晶区.从而开创了一种新型高品质焊接热源.

英文摘要：

The high frequency current pulse（≥20 kHz） output is difficult to achieve because of dynamic characteristic limit.The digital control TIG welding system with high frequency pulse assembled has been proposed in this research.This system adopts novel power circuit with DSP and CPLD control.By which the system can achieve high frequency pulse welding according to special scheduling and external characteristic control.This stable welding processing can decrease the number of blowholes during aluminum alloy welding,increase grain refining efficiency and improve the performance of welding joint.A novel high quality welding heat source has been created.