ROCOV scheme for Fault Detection and Location in HVDC sytems

A reliable DC fault protection system is essential for the development of HVDC grids. Therefore, this paper deals with the voltage derivative ROCOV scheme to locate and detect DC faults. The algorithm is able to differentiate internal and external faults considerably fast. The proposed algorithm is analyzed in a HVDC grid with different fault case scenarios. Finally, the ROCOV protection thresholds are discussed.The authors thank the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE) and GISEL research group IT1083-16), as well as from the University of the Basque Country UPV/EHU (research group funding PPG17/23)

Impact of a resistive superconductive fault current limiter in a multi-terminal HVDC grid

The relevance of multi-terminal HVDC grids is expected to increase in next years. However, there are still several technical, economical and legal limitations that interfere with the construction of those multi-terminal links. One of the main technical obstacles is the handling of DC fault currents, because the interruption of DC currents in HVDC systems is nowadays a challenge. Among other proposals, the application of Superconducting Fault Current Limiters (SFCLs) combined with a mechanical Circuit Breaker (CB) solves technically that issue, according to the analysis and simulation results presented in this paper.The authors thank the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE), the Basque Government (project ELKARTEK KK-2017/00083 and GISEL research group IT1083-16), as well as from the University of the Basque Country UPV/EHU (project EHUA15/25 and research group funding PPG17/23)