Title :
Studies of elastic waves caused by corona discharges in oil
Author :
Sakoda, T. ; Arita, T. ; Nieda, H. ; Ando, K. ; Otsub, M. ; Honda, C.
Author_Institution :
Dept. of Electr. Eng., Kumamoto Inst. of Technol., Japan
fDate :
12/1/1999 12:00:00 AM
Abstract :
In order to diagnose the deterioration of insulation and evaluate its location in oil-filled pole transformers, measurements of elastic waves brought by corona discharges in oil were performed, based on an acoustic emission (AE) technique. The detected signals in these measurements were analyzed by means of a fast Fourier transform (FFT) and their properties were discussed theoretically. It was found that the AE signals due to the Lamb waves of symmetric mode caused in a thin steel tank could be recognized easily by the FFT analysis of initial stages of the detected AE signals. This suggests that the accuracy on location of the AE sources in the transformer would be improved. Also, it was shown that a low pass filter was effective in improving the location accuracy
Keywords :
acoustic emission testing; corona; elastic waves; fast Fourier transforms; insulation testing; low-pass filters; surface acoustic waves; transformer oil; Lamb wave; acoustic emission signal; corona discharge; elastic wave; fast Fourier transform; low pass filter; oil insulation; oil-filled pole transformer; steel tank; Acoustic emission; Acoustic measurements; Corona; Fault location; Oil insulation; Performance evaluation; Petroleum; Power transformer insulation; Signal analysis; Signal detection;
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
