A Fabry–Perot (F-P) fiber acoustic sensor, which can work under high-temperature harsh environment with temperature self-compensation, is designed and prepared. A condenser was used to maintain the sensor to work in a stable temperature environment. Because of the special structure of the sensor and the function of the condenser, the cavity variation of the sensor caused by changes of external temperature from −10°C to 500°C would not exceed 8 nm. The experimental results show that the sensor has a good frequency response in a range of 1 to 5 kHz and the field experiment results show that it could be used for hydraulic decoking online monitoring by judging the acoustic frequency spectrum.
One of the most important equipment in high voltage power grid system is power transformer, however there are still some limitations on traditional methods of online partial discharge monitoring. Considering the advantages of optical fiber sensing technology, in this paper we do some research on fiber optics F-P sensing which can be used in transformer on online partial discharge monitoring. It also contributes to the improvement of the reliability of power system safety monitoring. This paper designs an equipment scheme for fiber optics F-P sensor, strictly fabricates the sensor according to the fabrication procedure. Moreover, we build a reasonable signal demodulation system for fiber optics F-P sensing, doing a preliminary analysis of online partial discharge signal monitoring,Partial discharge online monitoring system including different intensity discharge with a same sensing distance and a same intensity discharge with different sensing distances. Finally we make a detailed analysis of experimental result.