新型变极性焊接电源二次逆变电路及其控制技术

A novel secondary inverting circuit of the variable polarity welding power supply and its control technology

提出了一种用于变极性焊接电源的新型半桥式二次逆变电路拓扑,它由续流耦合电感、IGBT半桥电路及其RC缓冲电路组成.该电路既能确保在极性切换过程中获得快速的焊接电流换向速度,又能够通过硬件电路本身提供足够高的再燃弧电压,用以在焊接电流过零瞬间重新引燃电弧.针对新型半桥式二次逆变电路的特点,研究了开关切换控制策略以及换向电流控制策略.结果表明,电源系统在具有良好的变极性输出性能的同时,还有硬件电路结构简单、成本低、系统效率高等优点,具有很好的产业化应用前景.

A novel topology of half-bridge circuit,which is used as the secondary inverter of a variable polarity welding power supply,is proposed,and it is composed of a coupling inductor,a half-bridge circuit realized by two IGBTs and their RC snubber circuits.This kind of secondary inverting circuit could provide a high commutation rate of welding current from one polarity to another during the process of polarity exchange,and it could also generate a high enough voltage to re-ignite the arc when current zero-crossing.The control strategies of switches exchange and exchange current are also researched for the better and reliable control of the welding power supply system.Experimental results show that the welding power supply system developed here has an excellent polarity exchange performance and the advantages of simple structure,low cost and high efficiency,and thus has broad prospects of production application.