Contents I. Introduction
With the steadily increasing amount of the harmonic pollution, the detection of the sources of distortion has become one of the topical issues for power quality assurance and for the attribution of responsibility between customers and utilities for disturbances affecting the power systems. The scientific debate is still open on this issue and several methods have been proposed for the harmonic sources detection [1]–[6]. They can be classified in single-point and multi-point methods and they make use of different quantities and indices, which are evaluated starting from voltage, current or power measurements. As regards this last quantity, the harmonic active power is often considered, but it was shown that also the nonactive power components can provide some useful information for the localization of the sources of distortion [7]–[8]. As regards the electric power quantities to be used in nonsinusoidal conditions, the only available standard is the IEEE Std. 1459, updated on March 2010 [9]. It provides a set of power definitions (both active and nonactive), in order to quantify the flow of electrical energy in single-phase and three-phase systems under sinusoidal, non-sinusoidal, balanced, and unbalanced conditions. The aforesaid definitions are meant to give guidance for the quantities to be measured or monitored for revenue purposes, engineering economic decisions, and determination of major harmonic polluters. The approach of the IEEE Std. 1459 is based on the separation of the fundamental components from the harmonic content of voltage and current. This approach allows to measure the traditional quantities used for the current billing strategies (active, reactive and apparent powers and energies, and related power factor), and to introduce some other power quantities which can be used to assess the harmonic pollution level at the metering section. In literature some papers can be found concerning the measurements based on the IEEE Std. 1459 [10]–[18].
