Primary and backup fault detection techniques for multi-terminal HVdc systems: A review

Abstract

Fault detection and location estimation in a multi-terminal high voltage direct current (MTdc) transmission systembased on voltage source converter (VSC) technology plays a vital role in enabling the interconnection of renewable energysystems in Europe. In this study, a comprehensive overview of the development of fault detection and location estimationtechniques in the area of VSC-based MTdc network is given. The progress in various primary and secondary protectionalgorithms is introduced and compared in terms of high fault resistance, complexity, and communication. Besides, this studyinvestigates the suitability of existing fault detection techniques, compares techniques, and highlights their shortcomings.Additionally, this study also suggests unconventional ways to improve backup protection techniques and discusses futuristicmethods to improve the fault diagnosis process.