Effect of Low Harmonic Current Under Large Transformers on Harmonic Resonance Assessment in Industrial Systems

Abstract

This research suggests suppressing and preventing the effects of small harmonic currents generated by ac drives compared to the size of the transformer. However, it can produce resonance and high destructive power. The harmonics being measured today cannot predict phenomena or interpret what is happening in the system. As a result, the design of the circuit to improve the power factor and compensate for reactive power does not meet the requirements. The incorrectly designed output is installed on an existing system. This results in a capacitor explosion that directly affects the electrical system. The study of the incorrect design results was carried out in collaboration with ten industrial factories. Every plant had a small harmonic current generated by the ac drive compared to a transformer. Moreover, there were reports of capacitor explosions causing severe damage. Methods of system-wide verification and design of power factor correction systems using harmonic filter circuits and the new design results have been reported. Finally, this paper demonstrates how to suppress the resonance harmonics problem in a simplified way by choosing a tuned filter.