IEEE 1564-2014

This guide identifies appropriate voltage sag indices and characteristics on electrical power and supply systems as well as the methods for calculating them. Methods are provided for quantifying the severity of individual voltage sag events (single-event characteristics), for quantifying the performance of multiple events at a specific location (single-site indices), and for quantifying the performance of multiple events for the whole system (system indices). The methods are appropriate for use in 50/60 Hz transmission, distribution, and utilization electric power systems, though there may be applications to systems with other fundamental frequencies.