Discharge acoustic signal detection in insulating oil using the optical fiber Sagnac interferometer

In this paper, an optical fiber sensor (OF sensor) utilizing the principal of the Sagnac interferometer was proposed to detect the discharge acoustic signals which generated from a needle‐sphere electrode system in insulating oil. The performance of the OF sensor was checked by a sinusoidal calibration signal generated by a PZT actuator at 198 kHz. The detected discharge signals consisted of the acoustic signal and electrical noise. The noise signal could be removed by a digital low‐pass filter. It was demonstrated that the OF sensor in this research had a possibility to detect the discharge acoustic signals in the power apparatus.