DocumentCode :
419960
Title :
Determination of frequency variation effect on DFT-based algorithms for harmonic and flicker measurements
Author :
Chen, M.T. ; Yu, Z.M.
Author_Institution :
Nat. Kaohsiung Univ. of Applies Sci., Taiwan
Volume :
1
fYear :
2003
fDate :
7-12 Sept. 2003
Firstpage :
422
Abstract :
Harmonic distortion and voltage flicker are among the major causes resulting in growing concerns about electric power quality, and DFT-based algorithms have been widely used in their instrumentation and measurement. Though the pit-falls of DFT had been noticed, the effects of system frequency variation on the accuracy of the measurements have never been clearly determined. In this paper, to facilitate the accurate application of DFT under the situation of ever-changing system frequency, the effects are theoretically derived from the harmonic and flicker computations for the case of constant sampling time interval and truncating duration. The results show that the discrepancies in amplitude of individual harmonic and in total harmonic distortion factor over the normal system frequency variation range of 60±0.1 Hz are trivial, but the errors in harmonic phase and flicker are much more serious. In addition, different harmonic-distorted and flicker-modulated waveforms are simulated, and the effects of the system frequency variation on their measurements are evaluated. The results accord with those in theory.
Keywords :
discrete Fourier transforms; harmonic distortion; power supply quality; power system harmonics; power system measurement; DFT-based algorithms; discrete Fourier transform; electric power quality; flicker measurements; frequency variation effect; harmonic distortion; system frequency variation; voltage flicker; Discrete Fourier transforms; Distortion measurement; Frequency measurement; Instrumentation and measurement; Power measurement; Power quality; Power system harmonics; Sampling methods; Total harmonic distortion; Voltage fluctuations;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Transmission and Distribution Conference and Exposition, 2003 IEEE PES
Print_ISBN :
0-7803-8110-6
Type :
conf
DOI :
10.1109/TDC.2003.1335261
Filename :
1335261
Link To Document :
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