DC side filters for multiterminal HVDC systems

Multiterminal HVDC power transmission systems present challenges in the specification and design of suitable DC side filtering. This document examines the existing experience and addresses the particular technical problems posed by multiterminal systems. The filtering requirements of small taps are discussed, as is the potential use of active filters. Aspects of calculation and design are considered and recommendations made to guide the planners and designers of future multiterminal schemes.