逆变弧焊电源低频磁场辐射的分析

Investigation of low-frequency magnetic field radiation on inverter welding power source

关键词:  逆变弧焊电源  低频磁场  测量  电磁曝露

Key words:  inverter welding power source  low-frequency magnetic field  measurement  magnetic filed radiation exposure

摘要:

分析了焊接电源和焊接电缆周围磁场产生的机理,并通过测量来验证分析的准确性.结果表明,由于逆变焊接电源内部的整流和逆变模块对电流的多次调制作用,导致焊接电源周围形成工频磁场、整流单元和逆变单元产生磁场的叠加效应;电缆周围的磁场频率主要与IGBT(isolated gate bipolar transistor)工作频率有关,电缆周围低频时变磁场强度跟电流的纹波近似成正比,而与距离近似成反比.电缆的弯曲或者操作人员紧靠电缆都会对操作人员造成额外的电磁辐射,所以对弧焊环境电磁辐射的定量描述和认识,对于规范焊接操作,尽可能降低从业人员电磁曝露的影响具有重要意义.

Abstract:

The mechanisms of two kinds of magnetic field mainly distributed around power source and cables are analyzed,and their accuracy is verified through measurements.It's found that several modulation effects on current from rectifier to inverter module in the power source result in stacking effect of magnetic field among power-frequency magnetic field and magnetic fields generated by the rectifier and inverter module.Furthermore,the magnetic field frequency around the cables strongly depends on the frequency of IGBT;low-frequency and time-varying magnetic field strength increases as the current ripple increase,but varies inversely as distance approximately.Extra electromagnetic radiation to operator results from closing to and bending the cables,therefore,it's great significant to further understand and descript the electromagnetic radiation under welding environment to standardize the welding criteria and also to reduce magnetic filed radiation exposure as far as possible.