To provide a partial discharge source discrimination device of an oil-immersed transformer, which discriminates a type of a discharge source, whether it is bubble discharge or foreign material discharge.
An electromagnetic wave radiated by internal discharge at an internal antenna 2 provided on a flange part 1a of a transformer container 1 is detected as an electrical signal, and the electrical signal is subjected to FFT process by an FFT (fast Fourier transformation) processing device 4 to obtain FFT processing data. The signal discrimination part 5 determines the bubble discharge by bubbles in insulating oil when data with signal intensity greater than a noise level only in a frequency region of less than a predetermined frequency exists, and determines the foreign material discharge by foreign material in the insulating oil when the data with signal intensity greater than the noise level in a frequency region beyond the predetermined frequency exists. The type of the discharge source is discriminated by focusing on a difference of frequency characteristics of the radiated electromagnetic wave according to the discharge source of partial discharge.
TSUJI TAKAMASA
WADA KOTARO
Masuo Oiwa
Toshihide Kodama
Takenaka Ikuo
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