Innovative, robust and secure industrial solutions using microprocessor relays

This paper provides real-world examples of the benefits to industrial systems when aging and obsolete electromechanical relays are replaced with modern, microprocessor-based relays. Microprocessor-based relays eliminate failure and degradation of operations due to moving parts. They also reduce or eliminate the time to detect a failure via internal self-test diagnostics and monitoring, information storage, and communications that immediately publish alarms and alerts. Driving the mean time to detect failures to zero with instantaneous alerts of self-test alarms dramatically improves the reliability of systems that formerly relied on periodic manual tests of devices to detect failure. In fact, any failed electromechanical devices in service today will remain undetected until they are tested or until they fail to operate while in service. IEC and IEEE reliability measures based on time to detect failure and repair or replace are both improved with instantaneous detection and notification. In addition to measurably improved reliability, microprocessor-based relays enable many new and innovative applications within industrial and power plant installations. Self- test information and analytics, sequential events records, event reports, and data and asset condition monitoring support a wealth of applications. Relay networks share information to improve system commissioning and then to manage the plant. Sophisticated load management, load shedding, and voltage regulation are easily deployed with built-in features of modern, microprocessor-based relays and information processors. Programmable automation controllers (PACs) are rugged devices with extremely high uptime due to construction methods similar to mission-critical relays. Since PACs perform power system and process control logic equally well, new opportunities exist to combine relays and PACs within the same communications network to improve power system efficiency and process availability. This paper outlines real-world applications that brought value and justification to complete protective relay and PAC upgrades.