变电站复合材料绝缘子的动力特性与地震易损性研究

DYNAMIC PROPERTIES AND SEISMIC FRAGILITY OF SUBSTATION COMPOSITE INSULATORS

复合材料在变电站绝缘子上的应用,有望提高电气设备的抗震性能。测试了复合材料绝缘子的动力特性、弯曲刚度和承载能力;运用测试结果,建立了该复合材料绝缘子构成的电气设备的有限元模型;基于概率地震易损性分析理论,研究了电气设备的地震易损性。结果表明,复合材料绝缘子中套管与金属法兰的胶装连接段是抗弯承载力的薄弱部位,该段抗弯刚度明显小于套管刚度;该绝缘子组成的电气设备在0.4 g等级地震下发生中度和重度失效的概率较小,但轻度失效的概率达38%,提高胶装段抗弯能力是提高抗震性能的关键;以失效概率为指标的易损性分析实现了电气设备抗震性能的概率化评价。

The adoption of composite materials in substation insulators is expected to improve the seismic performance of electrical equipment. The dynamic properties, bending stiffness, and strength of a composite insulator are tested, and the results are employed in FE modeling of electrical equipment which uses the composite insulator. The seismic fragility of the equipment is analyzed based on the theory of Probabilistic Seismic Fragility Analysis （PSFA）. The results show that adhesive joints between composite tube and metal flange are a weak point in bending, and the stiffness of the adhesive joint is smaller than that of composite tube. When subjected to a 0.4 g level ground motion, seismic fragility of the equipment formed by composite insulators is small for moderate and severe levels of damage, but as large as 38% for minor level of damage. Increasing the flexural strength of adhesive joint can be effective in improving seismic performance. Taking the failure probability as index of seismic fragility, the paper presents a probabilistic evaluation of eletrical equipment＇s seismic performance.