The Impacts of AC Filters to Power Grid Harmonic in UHVDC Converter Station

The UHVDC converter station is usually equipped with multiple sets of AC filters and capacitors, which can filter out harmonics at the AC side and make compensation for the reactive power consumed by converters. The impedance-frequency characteristic of the parallel sets of AC filters and capacitors is complex, which can easily lead to harmonic amplification in some frequency ranges. Therefore, it is urgent to make research about the overall filtering performance and partial harmonic amplification of AC filter sets at present. The admittance-frequency characteristics of the AC filter sets are used to analyze the overall filtering performance and partial harmonic amplification of AC filter sets. A practical case of an UHVDC converter station is presented to analyze the impacts of AC filters to power grid harmonics, and the results of the ETAP simulation model verify the effectiveness of the theoretical analysis.