This newly developed guide compiles information on the application considerations ofprotective relays to ac transmission lines. The guide describes accepted transmission lineprotection schemes and the different electrical system parameters and situations that affect theirapplication. Its purpose is to provide a reference for the selection of relay schemes and to assistless experienced protective relaying engineers in their application.

The study of transmission line protection offers an opportunity to examine many fundamental relaying considerations that apply, in one degree or another, to the protection of other types of power system equipment. Each electrical element, of course, will have protection problems unique to itself; however, the concepts associated with transmission line protection are fundamental to all other electrical devices and provide an excellent starting point to examine and appreciate the implementation of all power system protection. The basic relaying characteristics of reliability, selectivity, local and remote backup, zones of protection, coordination, and speed ar...

Provide a reference document to be utilized by those responsible for the relay protection of transmission lines.