In order to realize the wide range of non-contact monitoring and fast and accurate positioning of the voltage breakdown of gas insulated metal-enclosed switchgear (GIS) equipment, and to improve the quality of the installation and commissioning of GIS equipment as well as the progress of the project, the study proposes a non-contact acoustic visualization breakdown positioning technology for GIS equipment. The acoustic sensor array is utilized to collect multi-channel sound signals, extract the abnormal sound image and locate the abnormal sound position. At the same time, a multidimensional filter is designed to filter the noise signal and extract the breakdown signal. Combining the air-domain filtering technology and microphone array signal testing theory, the acoustic visualization algorithm is optimized, the sparse Bayesian solving framework is introduced to accurately solve the unknown source strength, and the diagonal matrix noise reduction is used to suppress the environmental noise and achieve the precise location of the breakdown defects. Experiments show that the frequency band of the breakdown sound signal is about 10Hz~6.7*106Hz, in which the energy attenuation of the audible part is small, which is suitable for non-contact monitoring. Through the improved demodulation scheme, the side-mode rejection ratio is increased by 16.9dB, which effectively improves the accuracy of the detection signal. The system can realize quasi-distributed monitoring with more than 43 probe points, and the positioning accuracy of the middle part of the sensing fiber is up to more than 95%, which effectively reduces the scope of disassembly and overhaul. The research method solves the limitations of traditional ultrasonic localization technology and provides a new technology for efficient fault localization of GIS equipment.
