Modeling and Estimating Current Harmonics of Variable Electronic Loads

• Published in: IEEE transactions on power electronics Vol. 24; no. 12; pp. 2803 - 2811
• Main Authors: Wichakool, Warit, Avestruz, Al-Thaddeus, Cox, Robert W., Leeb, Steven B.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Approximation; Diodes; Electric variables control; Electronics; Energy consumption; Estimating; Experiments; Harmonic analysis; Harmonics; Inverse problems; Inverters; Mathematical models; Monitoring; Power consumption; Power system harmonics; Power system modeling; Predictive models; Rectifiers; spectral analysis; switching functions; Variable speed drives
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2009.2029231

This paper develops a model for relating input current harmonic content to real power consumption for variable electronic loads, specifically for loads' actively controlled inverters energized by an uncontrolled rectification of the utility. This model serves as the basis for a method for estimating and disaggregating the power consumption of variable speed drives (VSDs) and rectifier loads from other constant power loads. This method can be used for nonintrusive power monitoring. The approach described in this paper uses the approximate switching function of the rectifier to derive the best estimating function for the fundamental current harmonic from a finite set of current harmonics uniquely associated with the operation of the drive. Experimental results show that the proposed VSD power and harmonic estimator can track VSD power consumption for monitoring given knowledge or an estimate of the input current harmonic content.