Disturbance Monitoring Equipment [DME]
Devices capable of monitoring and recording system data pertaining to a Disturbance. Such devices include the following categories of recorders* :
• Sequence of event recorders which record equipment response to the event
• Fault recorders, which record actual waveform data replicating the system primary voltages and currents. This may include protective relays.
• Dynamic Disturbance Recorders (DDRs), which record incidents that portray power system behavior during dynamic events such as low-frequency (0.1 Hz – 3 Hz) oscillations and abnormal frequency or voltage excursions
*Phasor Measurement Units and any other equipment that meets the functional requirements of DMEs may qualify as DMEs.