Abstract: Real 110 kV capacitor group equipment in an UHV substation was tested in this study on a simulated seismic vibration test bench. Through the white noise random excitation, dynamic characteristics of the real equipment is clearly defined, while the acceleration, strain and displacement parameters of key parts of the equipment in the case of earthquake are measured by standard time-history wave excitation, and consequently seismic responses of capacitor banks are determined. Our test results show that the first-order frequencies in two horizontal directions of the capacitor bank equipment are 2.27 Hz and 2.31 Hz respectively, so they are highly seismically vulnerable. When inputting a standard time-history wave form with a peak acceleration of 0.4g in the test, the maximum stress of insulator at root of the capacitor bank is 40.80 MPa, which is less than the stress to cause material failure. Test results also show that an amplification effect to seismic acceleration exists in each layer structure of the capacitor bank. Under the action of seismic, the pillar insulator of the equipment becomes a vulnerable part in earthquake. In this regard, the anti-seismic capability of the insulator can be strengthened by improving the strength of materials and the stiffness of concerned connections.

Key words: UHV substation, capacitor bank, seismic vibration test bench, seismic response