Boundary Protection Scheme for HVDC Transmission System

HVDC has the advantages of lower cost and stronger controllability, and has been widely used in the optimal configuration of renewable energy and asynchronous interconnection of power grids. The protection of HVDC transmission lines has also become a hot topics. This paper proposed a novel boundary protection for HVDC line. Based on the traveling wave's attenuation effect by the line, the fault area is judged by the difference of the high-frequency voltage and current transient components. If the fault is close to the rectification side, the internal and external faults of the line are identified by the protection of the inverter side, otherwise, the internal and external faults are identified by the rectification side. Finally, a large number of simulation results based on PSCAD prove that the proposed method can accurately identify the internal and external faults of the line and has certain resistance to transition resistance.