超高压输电线路架空地线复合绝缘子断裂分析

Analysis of Composite Insulator Fracture of Overhead Ground Wire of Extra-high Voltage Transmission Line

分析超高压输电线路全绝缘架空地线复合绝缘子断裂原因,提出改造措施,确保线路安全稳定运行。通过对绝缘子进行断面特征及内部解剖检查,并结合绝缘子拉力试验和受力分析结果,认为由于压接式U型联结头设计裕度不足,在覆冰的情况下绝缘子承受横向切力,使U型联结头与三角联板互卡,横向切力足够大时导致绝缘子断裂。在绝缘子接地端和联板之间增加直角挂板,使绝缘子与联板间有足够活动裕度,有效缓冲了不平衡荷载,解决绝缘子断裂问题。该方法简单、有效,经济可靠,在今后的全绝缘地线建设、改造中可借鉴实施。

Reasons of composite insulator fracture of full insolation overhead ground wire of extra-high voltage transmission line are analyzed. Modified measures are proposed which guaranteed the security operation of transmission line. By inspecting the fracture surface characteristics and internal anatomy, and combining with results of insulator tension test and force analysis, it is considered that the design margin of crimp U type connecting head is not sufficient, and insulators are under the transverse shear force in the ice covering situation which cause the stuck of the U type connecting head with the triangle connecting plate, and insulators will be broken if the transverse shear force is big enough. Right angle hanging plate is added between the U type connecting head and the triangle connecting plate to make enough movement space which can slow down the unbalance load and solve the insulator fracture problem. The proposed method is simple, effective, economic and reliable which can be referenced and implemented in the construction and modification of full insulation overhead ground wire in future.