SHUNT ACTIVE FILTER FOR HARMONIC MITIGATION OF A RESISTANCE SPOT WELDING MACHINE

Abstract

This paper introduces a design and simulation of an adaptive shunt active filter (SAF) for harmonic mitigation of a resistance spot welder RSW. This type of welding machines causes unacceptable current distortions in the utility electrical distribution system, especially when an adjacent manufacturing facility with extensive electronic controls exists. This paper demonstrates effective use of active low-pass filter with the PWM carrier strategy to control the current of active filter. The method is based on frequency domain. In this study, a model of a typical power system coupled with RSW is presented. The studied system and the active filter are implemented in PSIM software, representative waveforms and spectral analysis is presented, simulation results show that the proposed active filter is very effective in harmonic elimination of the RSW.