Seismic Response and Failure Mechanism of Radiator and Conservator Connections in a 154 kV Transformer Based on Shaking Table Tests

Transformers are critical components in power systems, and their functionality must be maintained during seismic events. This study conducted multi-directional shaking table tests on a full-scale 154 kV transformer to investigate the seismic response and failure mechanisms of radiator and conservator connections. Measurements of relative displacement, acceleration, and test response spectra (TRS) indicated stable responses of 0.5–1.2 g for the transformer body, whereas the bushings and radiators exhibited amplified accelerations of up to 4 g and 2 g, respectively, along with relative displacements exceeding 20 mm. Under the 500-year return period input motion, leakage was observed at the lower radiator elbow, which is attributed to the combined effects of concentrated relative displacement, acceleration amplification, frequency-dependent energy concentration, and local structural discontinuities. The observed damage patterns were consistent with leakage incidents reported during the 2024 Noto earthquake in Japan. Based on the experimental findings, this study discusses seismic performance enhancement measures for radiator connections and provides experimental evidence to support the seismic safety evaluation of transformers with similar configurations.