A novel composite control based active DC filter applied in HVDC system

How to eliminate harmonics is one of the key technologies of high-voltage direct current transmission systems. This paper details the principle of the active DC filter applied in the HVDC system, and proposes a two-degree-of-freedom composite control strategy. The results of both simulation based on EMTDC/PSCAD and experiment on a 30 kVA HVDC system validate that the proposed control system is feasible and capable of canceling the harmonics efficiently.