Feasibility study of ac and dc-side active filters for hvdc converter terminals

This paper evaluates the technical and economic feasibility for active filtering of dc-side voltage harmonics and the ac-side current harmonics produced by a HVDC converter. The following designs for the active filter concepts are compared with the existing ac-side and dc-side passive filters used at the Dickinson terminal of the CU HVDC transmission line proiect: the dc-side active filter consisting of a capacitor coupled current injection source to actively “neutralize” the 12th, 24th and the 36th harmonics and, • the ac-side active filter designed to provide the same fundamental frequency reactive VARs as the existing passive filters. Controlled currents are injected to actively filter the 11th and the 13th harmonic currents. A cost comparison is made between these active filter designs and the cost of the existing passive filters supplied by the United Power Association (UPA).