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.