IEEE Guide for Protection System Redundancy for Power System Reliability

This guide is developed to assist users in selecting the appropriate level of protection system redundancy for power system reliability based on the best industry practices. It defines protection system redundancy and examines the effect of protection system components on redundancy. Different concepts of redundancy as related to physical location, instrument transformer, relay scheme, and communication systems are discussed. Redundancy application considerations for various power system elements are presented. (An errata for this standard is available at https://standards.ieee.org/wp-content/uploads/2022/12/C37.120-2021_errata.pdf)