Functional integration in modern distance relays improves the reliability of power systems

Modern distance-type protection relays include many protection elements such as overcurrent, overvoltage, undervoltage, underfrequency, overfrequency, breaker failure, synchronism check, out-of-step blocking and tripping, pilot protection schemes, digital relay-to-relay communications capability, programmability, and math functionality. Functional integration in modem numerical distance-type relays provides protection engineers the tools and flexibility to design more secure and dependable protection and control schemes. There are many applications of effective use of integrated functions in modern distance-based protection devices to improve the reliability and security of protection and electric power systems. In this paper, however, we present only a few of these applications.