Reliability of Microprocessor-Based Relay Protection Devices: Myths and Reality

Abstract

The article examines four basic theses about the ostensibly extremely high reliability of microprocessor-based relay protection (MP) touted by supporters of MP. Through detailed analysis based on many references it is shown that the basis of these theses are widespread myths, and actually MP reliability is lower than the reliability of electromechanical and electronic protective relays on discrete components.