A new non-communication protection technique for transmission lines

TLDR

The authors propose a new non‑communication protection technique for transmission lines. The method detects fault‑generated high‑frequency current transients, applies a multi‑channel filter to isolate specific frequency bands, and compares their spectral energies to distinguish internal from external faults. The technique eliminates the need for a communication link, preserves the robustness of transient‑based protection against fault type, position, path resistance, and inception angle, and is unaffected by CT saturation, busbar short‑circuit levels, or source network configuration.

Abstract

This paper proposes a new noncommunication protection technique for transmission line protection. The technique relies on firstly the detection of fault generated high frequency current transient signals. A specially designed multi-channel filter unit is then applied to the captured signals to extract desired bands of high frequency signals. Comparison between the spectral energies of different bands of the filter outputs determines whether a fault is internal or external to the protected zone. In addition to the saving in costs through negating the need for a communication link, the technique also retains many advantages of the 'transient based protection' technology, such as insensitivity to fault type, fault position, fault path resistance and fault inception angle. It is also not affected by CT saturation, the power frequency short-circuit level at the terminating busbar or the precise configuration of the source side networks.