逆变CO_2焊接电源动特性对焊缝成形影响分析

Effect Analysis of Dynamic Characteristics of Inverter CO_2 Welding Power on Weld Formation

介绍了逆变CO_2气体保护焊接电源的动特性要求,设计了一种双闭环控制的电子电抗器,内环为电流负反馈,外环为电压负反馈。整个焊接过程中,电压反馈实时监控电弧负载状态,使得系统具有良好的自身调节能力。分析了电子电抗器的控制原理,在短路过渡的短路阶段和燃弧阶段使用不同的电子电抗器参数,使两个阶段电源动特性合理匹配。通过试验研究了在恒定电弧平均电压和恒定送丝速度下,电源动特性对焊缝成形的影响规律,结果表明,随着燃弧阶段时间常数与短路阶段时间常数的变化,电流平均值也发生相应变化,导致焊缝熔深变化。随着燃弧阶段时间常数的增大,焊接平均电流减小,焊缝熔深减小,而随着短路阶段时间常数增大,焊接平均电流增大,焊缝熔深增大。

The requirement of dynamic characteristics of inverter CO2 gas shielded welding power source was introduced,a electronic reactance which had double closed-loop was designed,the inner loop was negative current feedback,the outer loop was negative voltage feedback.Throughout the welding process,voltage feedback monitored the arc load status in real time,which makes the system have a good self-regulation capability.The control principle of electronic reactance was analyzed.Different parameters of the electronic reactor were used in the short circuit and arcing stages of the short circuit transition,which makes the dynamic characteristics of the two stages match reasonably.The effects of the dynamic characteristics of the power supply on the weld formation were experimentally analyzed under constant arc average voltage and constant wire feeding speed.The results show that as the time constant of the arcing stage and the time constant of the short-circuit stage change,the average value of the current changes,resulting in the change of the weld depth.With the increase of the time constant of the arcing stage,the average welding current decreases,the weld depth decreases.With the time constant of the short-circuit stage increasing,the average welding current increases,the weld depth increases.