Evaluation of Methodologies for Measuring Harmonics and Inter-Harmonics in Photovoltaic Facilities

The increase in electric power demand in face of environmental issues has intensified the participation of renewable energy sources such as photovoltaics, in the energy matrix of various countries. Due to their operational characteristics, they can generate time-varying harmonic and inter-harmonic distortions. For this reason, the application of methods of measurement based on traditional Fourier analysis, as proposed by IEC 61000-4-7, can provide inaccurate results. Considering the aspects mentioned herein, came the idea of the development of this work which aims to present the results of a comparative evaluation between a methodology arising from the combination of the Prony method with the Kalman filter and another method based on the IEC 61000-4-30 and IEC 61000-4-7 standards. Employed in this study were synthetic signals and data acquired through measurements in a 50kWp photovoltaic installation.

Authors:

• Anésio de Leles F. Filho
• Wesley R. de Oliveira
• Jéssica S. G. Pena
• Jorge A. C. Angarita

Keywords:

• Harmonics
• inter-harmonics
• IEC61000-4-7
• parametric estimators
• photovoltaic generation.

References:

[1] Reis, A. (2014) Uma Contribuiçãopara o ControleOperativo de
UnidadesEólicas: Modelagem, Regulação de Tensão e Minimização das
DistorçõesHarmônicas. (Tese) Doutorado - Universidade Federal de
Uberlândia, 2014.
[2] Ribeiro, P.F.; Paulillo, G. Aspectos da Qualidade da EnergiaElétrica no
Contexto das RedesInteligentes. RevistaQualidade de Energia, Cap. X,
p.40-50, Ed. 93, 2012.
[3] Baghzouz, Y. et al. “Time-varying harmonics: Part I - Characterizing
measured data”, IEEE Transactions on Power Delivery, v. 13, n. 3, p.
938-944, July 1998.
[4] Costa, F. F. (2005) Estimação de Harmônicos e Inter-
HarmônicosemSistemasElétricos. (Tese) Doutorado – Centro de
Ciências e Tecnologia, Universidade Federal de Campina Grande, 2005.
[5] Leonowicz, Z.; Lobos, T.; Rezmer J. “Advanced Spectrum Estimation
Methods for Signal Analysis in Power Electronics”, IEEE Transactions
on Industrial Electronics, v. 50, n. 3, p. 514-519, June 2003.
[6] Sachin K. J.; Singh S.N. “Review Harmonics estimation in emerging
power system: Key issues and challenges,” Electric Power Systems
Research 81. p. 1754–1766, June 2011.
[7] IEC 61000-4-7, 2002, Testing and measurement techniques – General
guide on harmonics and inter-harmonics measurements and
instrumentation, for power supply systems and equipment connected
thereto.
[8] IEC 61000-4-30, 2011, Testing and measurement techniques – Power
quality measurement methods.
[9] Hanzelka, Z.; Bién, A. Harmonics: 3.1.1 Inter-harmonics. Produced in:
AGH University of Science and Technology, July, 2004. In: Leonardo
Power Quality Initiative (Org. & Ed.) “Power Quality Application
Guide”, Available online in (30/03/2014):
http://admin.staging.copperalliance.eu/docs /librariesprovider5/powerquality-
and-utilisation-guide/311-interharmonics.pdf?sfvrsn=4.
[10] Marple Jr., S. L. Digital Spectral Analysis with Applications.
Englewood Cliffs: Prentice- Hall, 1987. ISBN 0-13-214149-3.
[11] Gelb, A. et al. Applied Optimal Estimation. London: M.I.T. Press, 1974.
[12] Kalman, R. “A new approach to linear Filtering and prediction
problems,” Trans. of the ASMEJ. Basic Eng., v. 82, p. 35-45, March
1960.
[13] Block, P. A. B. et al. “Power Quality Analyses of a Large Scale
Photovoltaic System,” The fifth International Renewable Energy
Congress - IREC, Tunisia, March 2014.