IEEE 1459-2025

This document provides quantity definitions for designing and using instrumentation for the measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, and unbalanced conditions.

This standard is intended for use in designing and using instrumentation for the measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, and unbalanced conditions. Because there are major differences between this document and its 2010 predecessor, some of the material is pedagogical in nature.

Revision Standard - Active. Definitions used for measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, or unbalanced conditions are provided in this standard. Mathematical formulas for measurements and the appropriate notations for expressing quantity values are given. Informative annexes discuss (A) the measurement observation period, (B) combining Fourier decomposition and phase-sequence components, (C) a systems approach to measurement, (D) filtering, (E) a Trust Metric and a No-trust Metric, (F) Source Apparent Power, and (G) omissions from the previous version of Std 1459. Expressions that were used in the past, as well as new expressions, are listed, as well as explanations of the features of the new definitions.