Seismic Response and Vibration Control of 220 kV Single Pole SF6 Circuit Breaker
The seismic performance of substation porcelain column-type electrical equipment is relatively weak,particularly for circuit breakers across various voltage levels.These circuit breakers are not only crucial and costly but also have a significant head mass,making them highly vulnerable to seismic activity.To address this,a finite element model of a 220 kV single-pole SF6 circuit breaker and bracket system was developed to analyze its seismic response and assess its seismic performance.The study evaluated the seismic response characteristics of key components within the circuit breaker and bracket structure.The analysis revealed that the acceleration and displacement at the top of the circuit breaker interrupter chamber are significant under strong seismic action,and the stress at the base of the ceramic column exceeds the limits specified by current standards.As a result,the seismic performance of the circuit breaker is deemed insufficient.To enhance its seismic capacity,damping controls were introduced at the bottom,middle,and top of the bracket using shock absorbers.The mechanical model of the damping element followed a bilinear approach.A comparative analysis of the seismic response of the circuit breaker,both with and without dampers,showed that all three damper arrangements had a beneficial impact on reducing seismic vulnerability.Among these,the top-of-bracket arrangement proved to be the most effective,followed by the middle arrangement.However,due to practical difficulties in installing shock absorbers at the top of the bracket in real-world applications,the middle arrangement can be considered as a viable alternative.
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