Fiber Optic MEMS Ultrasonic Sensor and its Application in Partial Discharge Detection

In this paper, an optical fiber based ultrasonic sensor was designed and applied to the detection and position of partial discharge (PD). The Fabry-Perot interferometer with a micro-electromechanical system (MEMS) diaphragm has been proven to have high sensitivity, with broadband acoustic frequency response up to 500 kHz and wide directivity. In the PD detection experiment, the minimum detectable pressure (MDP) of the fiber optical MEMS sensor is achieving 0.455μPaHz^-1/2. In addition, four ultrasonic sensors are arranged around the ultrasonic source to conduct localization experiments. The results show that the system has excellent localization performance in x, y and z directions. The favourable acoustic performance of the MEMS sensor provides a high-sensitivity and high signal-to-noise ratio (SNR) detection method for PD detection.