A Power-Quality Measure

• Published in: IEEE transactions on power delivery Vol. 23; no. 2; pp. 553 - 561
• Main Authors: Katsaprakakis, D.A., Christakis, D.G., Zervos, A., Voutsinas, S.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Area measurement; Cartesian coordinate system; Deviation; Disturbances; dynamic; Electric potential; Electric power generation; Electric variables measurement; Electrical engineering. Electrical power engineering; Electrical power engineering; Entropy; events; Exact sciences and technology; Frequency; Mathematical analysis; measure; Miscellaneous; Operation. Load control. Reliability; power; Power electronics, power supplies; Power measurement; Power networks and lines; Power quality; Power system dynamics; Power system security; quality; security; Spectra; Time measurement; variations; Voltage; Voltage measurement; Voltage measurement; Probabilistic approach; Power system economics; Power electronics; Coordinate system; Shannon theory; Implementation; quality; Graphics; security; measure; Electrical network; variations; Quality control; Pricing; Disturbances; Power markets; Energy quality; dynamic; Economic aspect; Safety; power; Service quality; events
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2007.915974

A power-quality (PQ) measure is introduced in this paper. The proposed measure, based on the Shannon's entropy, expresses the deviation of the examined voltage cycle from the ideal one. Two entropy concepts are introduced - the spectral and the probabilistic entropy. The two entropies, calculated for every voltage cycle, are properly combined to provide the PQ measure. The PQ measure is represented graphically on a 2-D Cartesian coordinate system. The PQ measure is calculated for the most common PQ disturbances. The graphical representation of the calculated PQ measurements leads to the definition of an area of acceptable PQ on the PQ measure 2-D diagram. The PQ of a power system may be evaluated by the proposed measure, by implementing voltage measurements during predetermined time periods in selected network nodes. The produced electricity price may be configured in terms of the measured PQ.