Designing Passive Harmonic Filters for an Aluminum Smelting Plant

This paper presents the results of harmonic analysis and harmonic filter design for a grid-connected aluminum smelting plant. Harmonic-penetration-analysis studies are carried out to determine the system resonance frequencies and the individual and total harmonic voltage distortions for a wide range of possible system operating conditions including scenarios with N-1 and N-2 generation, an outage of a harmonic filter, and an outage of a rectifier transformer. A conceptual harmonic-filter-design procedure for the filters required for the smelting plant is presented. The suitability and robustness of the proposed harmonic filter configuration in terms of the filter´s component current and voltage ratings and corresponding rms values are investigated.