Mechanical Defect Field Detection for Operational GIS Equipment Based on Vibration Signal Analysis

GIS(Gas Insulated Switchgear) equipment is one of the most important equipment in power system, which plays an important role in the safe and stable operation of power grid. In addition to electrical fault, mechanical fault is also one of the main reasons endangering the safe operation of equipment, and vibration detection is a fast, effective and accurate method to detect and quantify mechanical defects of GIS equipment. Therefore, this paper first developed a set of portable equipment for mechanical vibration detection of GIS equipment. Then, the vibration detection of GIS equipment with abnormal noise and mechanical defects was carried out. Finally, the signals of different measuring points, distance and abnormal noise degree were compared and analyzed. Results show that the equipment can effectively detect the normal vibration and abnormal noise vibration of GIS equipment. When there are mechanical defects in GIS equipment, the frequency doubling component with 100Hz as the fundamental wave will be generated. The more abundant the frequency component is, the more intense the vibration will be, and the attenuation of the vibration signal along the axial propagation is obvious. Especially when the human ear can not hear the noise produced by abnormal noise and vibration, the device can also effectively detect and identify the abnormal noise and vibration state of GIS equipment, and can find the defect state of GIS equipment earlier.