The Anti-Interference Method of Michelson Optical Fiber Interferometer for GIS Partial Discharge Ultrasonic Detection

Optical interferometer acoustic sensors for GIS partial discharge detection are proposed in recent years. However, the stability of the sensing system for actual apparatus PD detection is less of a concern, especially for actual GIS. In this paper, an optical fiber acoustic sensing system based on Michelson interferometer for GIS PD detection was developed. And the influence mechanism of environmental noise on the stability of the sensing system was analyzed. And then, a method of phase tracking feedback to resist noise interference was proposed. The Michelson optical fiber interferometer with the phase feedback system worked as a high-pass filter. And the cut off frequency was 1.8 kHz in the design. Lastly, the antiinterference performance of the optical fiber interferometer was tested in an actual 126kV GIS. With the designed phase feedback control system, the stability was ensured for the on-site application of the optical interferometric acoustic sensing system.