# Study on Seismic Performance of a Mold Transformer through Shaking Table Tests
## 1 Introduction
Based on the test results, the dynamic characteristics in terms of the fundamental frequency and damping ratio, and dynamic amplification were assessed and compared between the non-structural elements with and without anti-seismic solutions. In addition, the seismic response of the tested prototypes was also evaluated in terms of fragility curves. Nonetheless, the studies on electrical and mechanical components, such as switchboards or transformers commonly used in structural buildings for power systems, are still limited [9; 10; 11; 12; 13]. [PERSON] et al. [9] performed a series of quasi-static cyclic loading and shaking table tests to investigate the behavior of a prototype diesel generator equipped with a restrained vibration isolation system. The test results indicated that the failure modes of the restrained isolators were severe fatigue damage of the connection between the vertical restraint rods and top plate, together with the pull-out failure of the vertical restraint rods. In addition, the incorporation of snubbers into the vibration system could provide more restrains, which resulted in effectively preventing the restrained isolators from plastic deformation and severe damage. [PERSON] et al. [10] performed a seismic fragility analysis of electrical equipment in a typical electric substation in the eastern United States by using actual earthquake damage data. The fragility analysis results revealed the expected performance of electrical equipment in the substation and provided the necessary data for the seismic performance evaluation of an entire electrical substation for reliability analysis. Moreover, [PERSON] et al. [12] experimentally investigated the seismic performance of an isolation system supporting heavy mechanical equipment. A centrifugal liquid chiller was used as a prototype specimen supported by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE)-type isolation system consisting of coil springs and rubber snubbers constraining vertical and horizontal displacement. The test results showed that the isolation system could effectively reduce the response of specimens by energy dissipation and reduce the amplification of the peak acceleration response at the center of the chiller mass with an increase of the peak input acceleration. In addition, the influence of parameters such as the gap size and rubber pad thickness on the seismic performance of the prototype was also analyzed and discussed in detail. In the present study, dynamic shaking table tests were carried out to investigate the seismic vulnerability of mold transformers, with the aim of expanding the knowledge of the behavior of mechanical and electrical non-structural components. A 1000 kVA hybrid mold transformer was selected as the test specimen, with conventional anchoring details connecting it to a concrete slab. The input acceleration time histories were artificially generated to match the requirements proposed by the International Code Council Evaluation Services Acceptance Criteria ICC-ES AC156 code [14], with different scaling factors. Moreover, random input signals were also used for dynamic system identification, according to FEMA 461 [15]. Based on the test results, the damage stages and dynamic characteristics of the mold transformer during tri-axial acceleration, simulating earthquake load, were evaluated and investigated in terms of the fundamental frequency, damping ratio, acceleration time history responses, and maximum displacement response, as well as dynamic amplification factors.