الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Welding machines causes excessive harmonic current and undesirable voltage distortion in the electrical distribution system and causes a malfunction of other equipment, especially when an adjacent manufacturing facility with extensive electronic controls exists. With the presence of harmonics, power transformers generates additional power losses are appearing in such electrical equipment and hence extra heating in the phase winding.
The different traditional and modern harmonic solutions are presented. The harmonic mitigation solution chosen was the shunt active filter. This work demonstrates effective use of active low-pass filter with the PWM carrier strategy to control the current of the active filter. The method is based on frequency domain. The studied systems and the active filter are simulated in PSIM softwares. Simulation results show that the proposed filter is very effective in harmonic mitigation of welding machines. In this study, harmonic measurements and analysis of flash butt welding machine and Arc welding machine. The results of harmonic analysis were compared with IEEE 519 limits. It was found that the total harmonic distortion of the input current exceeded the limits.