A New Filtering Scheme for HVDC Terminals Based on Damped High-Pass Filter

This paper presents the design and application of a recently developed damped high-pass (DHP) filter for the line-commuted converter HVDC terminals. The DHP filter can damp resonance at the noncharacteristic harmonic frequencies commonly encountered by multipulse HVDC links. A design method is developed to address two unique issues faced by HVDC filter design: a wide range of system impedances seen by a HVDC terminal and a variable reactive compensation configuration at the terminal. Both are challenging filter design problems even for traditional filter banks. Using realistic industry case and sensitivity studies, this paper has shown that the proposed filtering scheme and design method can result in saving in filter costs and space requirements without sacrificing performance in comparison with the common filtering schemes used at HVDC terminals. In addition, the proposed design concepts are also applicable to the design of other filters facing the same design issues.