Study of wavelet-based ultra high speed directional transmission line protection

A novel wavelet-based directional protection scheme is presented in this paper. Using the theory of wavelet singularity detection as a powerful signal-processing tool, the initial arrival of the traveling wave and its sign can be identified reliably. Characteristics of the proposed directional protection algorithm are analyzed and results of simulation studies are given. The wavelet-based directional protection scheme solves several problems existing in current protective relays and is suitable for use as an ultra high speed UHV/EHV transmission line protective relay.