Abstract: In order to analyze the structural characteristics and seismic performance of composite electrical equipment, a seismic shake table test is conducted on two types of ±800 kV composite post insulators used in the electric power projects, i.e., post structure with support and post structure without structure. The displacement, strain and acceleration responses of the key parts of the equipment are measured through white noise and seismic test. A comparative analysis is made of the seismic responses of the composite post insulators with/without support. The experimental results show: 1) the support slightly reduces the first order frequency while increasing the damping ratio of the test equipment, but has less influence on the damping ratio of the flexible equipment; 2) the stress and displacement responses are basically linear under the seismic excitation of 0.1 g to 0.4 g; 3) the support dynamic amplification coefficients of stress, displacement, acceleration and spectral acceleration are all less than 1.30 with the amplification coefficient of peak acceleration being the largest; 3) the support amplifies the spectrum of seismic waves in the part of high frequency, and 4) the structural frequency distribution of equipment on the seismic wave spectrum curve is positively related to the amplification factor of the support stress, and the support slightly enlarges the equipment displacement.

Key words: composite material, post insulator, support dynamic magnification factor, shake table test, seismic performance