An Optoacoustic Sensor System for Simultaneous Detection of Power Equipment Voiceprint and Discharge

Voiceprint and discharge ultrasonic detection are commonly used sensing methods for power equipment diagnosis in substations. Because of the relatively high cost and large size, they were generally only deployed for power equipment of great importance, such as power transformers. In this research, we designed a prototype of an optoacoustic sensor system consisting of wideband micro-electro-mechanical-system microphones and a visible camera. We also laid a signal processing framework to obtain the voiceprint of the power equipment and discharge ultrasonic emission. A testing platform was built to verify the performance of the proposed design. The results showed that the optoacoustic sensor system could simultaneously detect the voiceprint of the power equipment and ultrasonic discharge pulses. A significant signal-to-noise ratio (SNR) improvement can be achieved by employing FIR filtering and beamforming. The voiceprint SNR was improved by 2-fold, and the ultrasonic discharge emission SNR was improved by 32-fold. The optoacoustic sensor system can also locate the sound source by overlaying the acoustic field distribution on the visible photo.