Transient vibration study of GIS bus based on FEM

With the development of the economy, gas-insulated metal-enclosure switchgear (GIS) is widely used for its good economic benefits and other advantages. At the same time faults of GIS equipment occur occasionally in the field. Mechanical failure has become one of the common failures of GIS. At present, the study of GIS's vibration mostly is analyzing the vibration signal of the shell acquired by the piezoelectric acceleration sensor. Aiming at the working three phase enclosed horizontal gas insulated bus (GIB), the electromagnetic force of the shell was calculated by principles of electromagnetism. A three-dimensional numerical calculation model of horizontal GIB was built with the finite element method (FEM) software ANSYS to conduct transient vibration analysis. By exerting alternating electromagnetic force obtained through the electromagnetic analysis, the spatial distribution and time-varying characteristics of the metal shell's vibration were obtained. Results show the distribution of vibration accelerated speed is consistent with that of the velocity, and the value of the former is much bigger. The vibration signal on the two sides of the metal shell is more remarkable compared with other locations, and the frequency is the same with that of the electromagnetic force. These were both checked in the experiment. There are some high frequency components in the accelerated velocity signal of the nodes at both the top and the bottom of the shell. And closer the node is from the restrained end, smoother the accelerated speed wave is. The calculation model and analysis results can be used for the vibration analysis of GIS., condition monitoring and fault diagnosis.