With the rise of GIS voltage level and the popularization of its application

more and more GIS abnormal sound vibration problems appear on site.The GIS site abnormal sound vibration is caused by poor assembly

but also caused by the intrusion of high-frequency signals

and more puzzling is the strong or weak abnormal sound vibration that varies with the different GIS operation mode.This paper aims to analyze the causes of the strong or weak abnormal sound vibration

so as to prevent vibration from the source.This paper firstly theoretically analyzes the electric force and electromagnetic force existing between the conductor and the shell of GIS with no-load and load

and deduces the mathematical expressions of electric force and electromagnetic force varying with the applied voltage value

the carrying current value and the power frequency.In the no-load operation of GIS

only electric field force exists between the conductor and the shell

and the higher the voltage level is

the greater the electric field force will be.Therefore

abnormal sound vibration usually occurs in the field debugging and no-load running of ultra-high voltage level GIS.After the current is loaded

as the direction of electromagnetic force is opposite to that of electric field force

the resultant force between conductor and shell will be decreased

which weakens the abnormal sound vibration.The magnitude of the current determines the degree which the abnormal sound vibration is weakened

which presents the phenomenon that the abnormal vibration is strong or weak in GIS different operation modes.In order to avoid the abnormal sound vibration of GIS

the structural parameters should be adjusted in the GIS structure design so that the natural frequencies of the GIS shell and the long straight conductor can avoid the resonance zone of the forced vibration frequency

and this paper provide its fast calculation method.Through the theoretical analysis of GIS abnormal vibration and the research of structural design method

this paper provides the technical basis for antivibration design of GIS in the future.