Impact of welding equipment on power quality

In an industrial facility, many electrical consumers can affect the quality of electricity. Therefore, the freedom from interference sources of these devices and equipment can be crucial for quality and uninterrupted electricity supply. Electric welding equipment is also a possible source of interference. The electrical harmonic injections created by welding equipment into the electrical network can affect the operation of other consumers connected to the given distribution points and cause unjustified overheating and shutdowns of some network components. The aim of the research is to analyse the current harmonic injection of welding equipment of different types and modes of operation connected to the internal distribution network of the industrial facility. The effectiveness of the active harmonic filter built into the welding equipment was also examined in the paper. The results showed that the built-in active harmonic filter of the DC045 laser welding equipment was ineffective because the total harmonic distortion(THD) was about three times the 8% allowed by IEEE 519-2022 standard.The current harmonic injection of MIG 320 and MM403 type welding equipment was more than five times the permissible value of 5%. The current harmonic distortion of the PLAS140 type plasma-jet cutter equipment was below the 5% value allowed in the standard, thus it complied with it. Based on the measurement results, it can be concluded that the use of protection against harmonics is also necessary for welding equipment. Finally, proposals were made in the paper to reduce the effect of harmonics.