Significant Revisions to Power Quantity Definitions and Instrumentation Standards

Reactive power and power factor have been challenging to measure for a century. The revised IEEE Standard 1459 is intended to address the problems. In fact, two measurement-related standards have been revised. IEEE Standard 120 (Master Test Guide for Electrical Measurements in Power Circuits) deals mainly with instrumentation. It has been extensively revised and updated to reflect modern digital techniques. Standard 1459 (Standard Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions) deals with measurement. The power quantities in question are power, reactive power, apparent power and power factor. The manner in which these quantities are treated has been extensively revised to reflect the appropriate considerations of measurement science. The measurement of waveform period has been added as a part of these measurements.