| Title |
Detection of Ultrasonic Characteristics of Oil Corona by Wide-Band AE Sensor |
| Authors |
김인식(Kim, In-Sik) ; 이상우(Lee, Sang-U) ; 이동인(Lee, Dong-In) ; 이광식(Lee, Gwang-Sik) ; 김이국(Kim, Lee-Guk) |
| Keywords |
Acoustic Emission ; Ultrasonic Signal ; Corona Discharge |
| Abstract |
In this paper, using a wide-band AE sensor with the frequency range from 100[kHz] to 1.5[kHz], the frequency spectra of AE signals generated from the corona discharges of the needle-plane gap and from the partial discharges of an epoxy void were analyzed to determine the proper ultrasonic sensor with optimum frequency range according to the patterns of corona discharges. We also examined the propagation characteristics of AE signals in oil and the relationship between the magnitude of corona discharge and the magnitude of AE signals in peak-to-peak value under the application of 60[Hz] ac high-voltage. From these results, the main frequency spectra of AE signals emitted from the corona discharges of the needle-plane gap were about 130[kHz] by the fast fourier transform, but the main frequency spectra appeared to be 230[kHz] in the partial discharges of an epoxy void. The magnitude of AE signals was proportional to the magnitude of corona discharge and discharge current pulse with increasing the applied voltages. |