摘要
通过电信号采集平台,对焊机输入输出端电信号进行同步采集.分析弧焊电源整流电路,对输入电信号进行整流处理得到输入电压与电流,最终计算得到弧焊电源的输入功率.经过对比发现输出电流与瞬时输入功率峰值变化趋势基本一致.论述了变分模态分解(VMD)原理及方法,并对瞬时输入功率进行分解,得到一系列特征BLIMFs信号.通过对不同过渡模式(大滴过渡、短路过渡和混合过渡)下瞬时输入功率信号、特征IMF信号和焊接输出电流信号在频域上的对比分析,发现VMD能够有效得到低频(IMF1)、中频(IMF2)和高频信号(IMF3),且中频和高频信号表现出了焊机不控整流的脉动信息(300 Hz)以及电网的干扰.而低频IMF1信号与焊接输出电流信号频域一致性良好,并在时域上也有良好的一致性.结果表明了通过对输入瞬时功率的VMD,其低频分量能够有效表征焊接过程,从而为从输入端评定过渡过程稳定性提供了一种新思路.
The input and output signals of a welder were collected synchronously through the electrical signal acquisition platform.The rectifier circuit of arc welding power supply was analyzed,the input voltage and current were obtained by rectifying the input electrical signal,and the input power of arc welding power supply was calculated.It was found that the variation trend of output current and the peak value of instantaneous input power was basically the same by comparison.The principle and method of variational mode decomposition(VMD)were discussed,and the instantaneous input power was decomposed into a series of characteristic band-limited intrinsic mode functions(BLIMFs)signal.The instantaneous input power signal,characteristic intrinsic mode function(IMF)signal,and welding output current signal in different transition modes(e.g.,large-droplet transition,short-circuit transition,and mixed transition)were compared and analyzed in the frequency domain.The results revealed that VMD can effec-tively obtain low-(IMF1),medium-(IMF2),and high-frequency signals(IMF3).The medium-and high-frequency signals were found to exhibit pulsation related to the uncontrolled rectification of the welder(300 Hz)and disturbance from the grid.Furthermore,the low-frequency IMF1 signal agreed well with the welding output current signal in both the frequency and time domains.This elucidates the ability of the low-frequency component of the instantaneous input power obtained through VMD to effectively characterize the welding process,thereby providing new insights about the stability of the transition process as assessed from the input terminal.
作者
吕小青
苏浩洋
LüXiaoqing;Su Haoyang(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300350,China)
出处
《天津大学学报（自然科学与工程技术版）》
EI
CAS
CSCD
北大核心
2024年第4期394-402,共9页
Journal of Tianjin University：Science and Technology
基金
国家自然科学基金资助项目(52075372).
关键词
MAG焊
瞬时输入功率
变分模态分解
频谱分析
MAG welding
instantaneous input power
variational mode decomposition(VMD)
spectrum analysis
