Vibration Characteristics of GIS Under Multi-Frequency Sinusoidal Steady Current

When the new source and load are connected to the grid, many harmonic components are generated, and the harmonics will affect the vibration characteristics of the gas insulated switchgear (GIS). Firstly, the types and components of the harmonics generated when the new sources or loads are connected to the grid are analyzed and summarized. Then the vibration mechanism of the GIS busbar shell is analyzed and the relationship between vibration-related physical quantities and excitation current is investigated. Finally, the simulation model is established based on the existing GIS single-phase busbar shell in the laboratory as a prototype, and the vibration characteristics of GIS under the excitation of multi-frequency sinusoidal current are simulated. Through simulation calculations, it is found that the vibration amplitude of the GIS shell is roughly symmetrically distributed in the axial direction. And the electromagnetic force on GIS is proportional to the frequency of excitation current and the square of the excitation current amplitude. The vibration acceleration frequency of GIS is twice the frequency of the excitation current. When there are multiple harmonic currents, its vibration frequencies are richer and it is easier to cause mechanical resonance. The vibration under current excitation of 50 Hz, 100 Hz, 150 Hz, 200 Hz and 300 Hz is relatively weak, and the maximum vibration acceleration under these five excitation frequencies is 0.58 mm/s
²
. But under the excitation of the 5th harmonic (250 Hz) current, the vibration acceleration of the GIS busbar shell is about 80 mm/s
²
, which is much greater than the results under other frequency excitations.