Measurement of Complex Dielectric Permittivity in Oils from High-Voltage Transformers Using a Coaxial Probe
This work presents the results obtained in the measurement of complex dielectric permittivity of some samples of oil from high voltage transformers within a frequency range comprised between 100 MHz and 3 GHz. Three types of oil samples were considered: new, used and those used samples that have undergone a filtering process for their recovery and new use. The measurements were performed by using a low-cost probe adapted from an open-ended SMA coaxial connector. The values obtained in a vector network analyzer of the reflection coefficient, measured on the contact surface between the probe and the oil are used to calculate the real and imaginary part of the complex dielectric permittivity by using theoretical models of the cable’s open end. The results obtained permit assigning trust to this measurement and characterization method of the oils according to the value of the complex dielectric permittivity, given that it agrees with some values reported in the literature obtained through different methods.
Agilent Technologies, “Agilent Basics of Measuring the Dielectric Properties of Materials,” Notes of Application, June. 2006.
E. Piuzzi; C. Merla, “A Comparative Analysis Between Customized and Commercial System for Complex Permittivity Measurements on Liquid Samples at Microwave Frequencies,” IEEE Transactions on Instrumentation and Measurements, vol. 62, n5, pp. 1034-1045, May. 2013.
J. Baker, “Analysis of an Open-Ended Coaxial Probe with Lift-Off for Nondestructive Testing,” IEEE Transactions on Instrumentation and Measurements, vol. 43, n5, pp. 711-717, Oct. 1994.
M. Kuhn; M. Awida, “Open-Ended Coaxial Probe Measurements for Brest Cancer Detection,” IEEE Radio and Wireless Symposium, pp. 512-515, Jan. 2010.
A. García, J. L. Torres, “Dielectric Characteristics of Grape Juice and Wine,” Biosystem Engineering, vol. 88, n3, pp. 343-349, Jul. 2004.
J. Vrba and D. Vrba, “Temperature and Frequency Dependent Empirical Models of Dielectric Properties of Sunflower and Olive Oil,” Radio-engineering, vol. 22, n4, pp. 1281 -1287, Dec. 2013.
C. T. Dervos, C. Paraskevas, “A Complex Permittivity Based Sensor for the Electrical Characterization of High-Voltage Transformer Oils,” Sensors, vol. 5, pp. 302 -316, May. 2005.
S. Seewattanapon, P. Akkaraekthalin, “A Broadband Complex Permittivity Probe Using Stepped Coaxial Line,” Journal of Electromagnetic Analysis and Applications, vol. 3, pp. 312 -318, Aug. 2011.
A. P. Gregory, “Table of Complex Permittivity of Dielectric Reference Liquids at frequencies Up to 5 GHz,” ResearchGate, Technical Report, Jan. 2012.
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