Fully monitoring protection and control systems

Modern microprocessor-based IEDs offer many functions, which are underutilized by the industry. This paper will discuss using IED functionality to fully monitor the protection and control system, which will identify problems within the system before they manifest themselves by miss-operation. This paper will also discuss the use of these monitoring systems to lengthen the time intervals required for periodic testing of the protection and control system. Some of the monitoring techniques to be discussed include: trip coil, close coil, and lockout relay monitoring, usage of IED self-test alarm contacts, instrument transformer failure detection using analog GOOSE messaging & other level detection/comparison methods, station battery monitoring, oscillography cross-triggering, automated contact input & output testing and natural testing by event analysis.