Triggering tradeoffs for recording dynamics [in power systems]

Dynamics recording devices (DRDs) that monitor and record the transient or dynamic response of power systems are installed across power systems. DRDs that have been installed in the last decade have increasingly used digital computer implementation-these include digital relays, digital fault recorders, integrated electronic controls for substation automation and many digitally implemented controls such as excitation system controls and stabilizers. Here, the authors describe how DRDs and monitoring systems need triggering algorithms and settings that dependably and securely detect unusual events in the presence of normal power system events.