Defects in the secondary circuit of relay protection

Malfunctions include the operation of output relays and watchdog contacts, the reset of microprocessors, alarm or trip indication, acceptance of corrupted information over the communication link and the corruption of saved information or settings. On this basis, many researchers have proposed a large number of related technologies and research to improve the reliability of relay protection secondary circuit and quickly. Selectivity is a mandatory requirement for all protection, but the importance of it depends on the application. For example, unselective protection operation during a medium voltage network fault will cause an outage for an unnecessarily large number of consumers. While this is bad, It's not a. The performance of protective relay is affected by maintenance. [pdf]