Single-End Protection Scheme for LCC- HVDC Transmission Lines Based on High Frequency Components of Transmission Line Current

This paper proposes a single-end protection scheme based on high frequency components of DC line current for protection of transmission lines in LCC-HVDC system. The protection scheme deploys the boundary characteristics of transmission line which eliminates high frequency components of external faults due to presence of filter-reactor unit at the line terminal. The scheme consists of two criteria including fault detection criterion and protection criterion to distinguish between internal and external faults. The performance of the protection scheme is evaluated by performing numerous simulation studies considering different fault locations, fault resistance, length of data window, sampling frequency and change in the transmission line power as well. The simulation results confirm that the proposed protection scheme is capable of discriminating between different types of high resistance internal faults and external faults at DC and AC sides using only rectifier side measurements. Moreover, it is simple, fast and reliable, and does not need communication between transmission line ends.