Exploring Ieee Std. C37.120-2021 Guide For Protection System Redundancy For Power System Reliability

This paper covers principles of protection system redundancy and summarizes the IEEE C37.120-2021, Guide for Protection System Redundancy for Power System Reliability. This guide has been developed to assist users in applying protection system redundancy; to provide information about which factors to consider when designing redundant protection systems; and to address different approaches to applying redundancy depending on application areas and present practices. General considerations for redundancy are presented including its fundamentals, impact on power system reliability, and the factors affecting redundancy application and design. The effects of various protection system components on redundancy are discussed including instrument transformers, dc system elements, and relay and communication systems. Redundancy application considerations for power system equipment such as generators, buses, transmission lines, and power transformers are provided.