Approved & Proposed IEEE Smart Grid Standards
PC37.237 - Recommended Practice for Time Tagging of Power System Protection Events
This is a recommended practice for time tagging protection events and associated analog and derived measurements in electric power systems. It defines the meaning of a time tag, and defines reference times for common events and time-varying quantities. It provides methods to describe measurement and transport delays, and the overall accuracy of time tagging. Potential problems caused by delays in ancillary equipment and the use of different time scales in different locations (local time zones, for example) are identified and addressed.