绝缘子表面流注发展特性受伞裙形状的影响

Influence of Curved Profiles on Characteristics of Streamer Propagation along the Insulator Surfaces

绝缘子沿面闪络是电力系统中的常见事故,威胁着电力系统的安全可靠运行。本文将从抑制流注放电的角度,探讨绝缘子伞裙形状的设计。在"三电极"结构中,利用光电倍增管测量了不同伞裙形状的绝缘子表面流注传播特性参数:流注稳定传播电场、流注传播速度、流注发光强度。试验结果表明:绝缘子伞裙阻挡了"沿面"分量的传播,使其不能传播到达阴极板,而"空气"分量可以越过伞裙到达阴极板。此外,伞裙形状对沿面流注的传播特性有很大的影响。具体来说,伞裙外形弧度越大,沿面流注稳定传播场强越小,相同电场强度下的流注传播速度和发光强度越大。

The flashover along the insulator surfaces is common accident in electric power system. It threatens the safe and reliable operation of the power system. In the paper, the design of shed profiles of insulators is considered from the perspective of inhibiting streamer discharge. In three-electrode arrangement, the characteristic parameters of streamer propagation along insulators with different shed profiles are measured by photomultipliers, such as streamer stable propagation electric field, streamer propagation velocity and luminous intensity from streamer. The test results show that the ＇surface＇ component of streamer can not cross over the shed of insulator and never reachs the cathode, only the ＇air＇ component crosses the gap to reach the cathode. Furthermore, the shed profiles of insulators have a great influence on streamer propagation. Specifically, the electric field required for streamer stable propagation is in inverse proportion to the curved of shed profiles of insulators. Under the same electric field, the streamer propagation velocity and luminous intensity is in proportion to the curved of shed profiles of insulators.