engleski

Indices for Harmonic Distortion Monitoring of Power Distribution Systems

Among different power quality parameters, the voltage total harmonic distortion is important and is often studied. Different indices have previously been suggested to measure and monitor both the current and the voltage distortion in power systems, but the harmonic characterization of a power system can still not be performed in a satisfactory way. The state of the harmonic distortion is difficult to predict due to variability and a large number of unknowns, such as detailed consumer and system characteristics. In this paper, a new index describing the total harmonic distortion in current measurements, the total rated distortion (TRD), is suggested in order to simplify and standardize harmonic current measurements. Another index representing the increase of harmonic voltage distortion with TRD, the equivalent harmonic impedance zeq, is proposed as an efficient way of characterizing a particular site. It is analyzed when the zeq is increased or decreased with regard to the angle between harmonic voltages and currents. Finally, extensive harmonic measurements of a real distribution system were performed to prove the usefulness of the proposed indices.

harmonic distortion; harmonic analysis; power quality; power system measurements; power system monitoring

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