Title :
Diagnosis of moisture in oil/paper distribution cables - Part I: Estimation of moisture content using frequency-domain spectroscopy
Author :
Neimanis, R. ; Eriksson, R.
Author_Institution :
Programma Electr. AB, Taby, Sweden
Abstract :
Dielectric spectroscopy (dielectric response measurements) has been applied for nondestructive estimation of humidity in oil-paper cable insulation. The experiments have been based upon two field-aged cables, 20 and 50 years old. Paper samples from these cables have been characterized and subjected to environments with different relative humidity. Dielectric loss and capacitance have been measured in a frequency range 1 MHz to 1 kHz and related to the moisture content determined by Karl Fisher titration. A method has been verified where the moisture content is correlated to the minimum value of loss tangent (tanδ). A number of field measurements have been performed where the method has been applied to estimate the moisture content in the distribution cables.
Keywords :
capacitance measurement; dielectric loss measurement; distribution networks; moisture measurement; oil filled cables; paper; permittivity measurement; power cable insulation; 1 kHz to 1 MHz; Karl Fisher titration; capacitance; dielectric loss; dielectric response measurement; dielectric spectroscopy; distribution cables; frequency-domain spectroscopy; mass impregnated cable; moisture content estimation; moisture diagnosis; nondestructive humidity estimation; oil-paper cable insulation; Cable insulation; Dielectric loss measurement; Dielectric measurements; Dielectrics and electrical insulation; Electrochemical impedance spectroscopy; Frequency estimation; Humidity measurement; Moisture measurement; Oil insulation; Petroleum;
Journal_Title :
Power Delivery, IEEE Transactions on
DOI :
10.1109/TPWRD.2003.820417
