超高压输电线路覆冰舞动的静态特性研究

【作者】 黄敏；

【导师】 徐红兵； 庄毅；

【作者基本信息】 电子科技大学 ， 控制工程， 2010， 硕士

【摘要】 架空输电线的覆冰灾害是一个国际上普遍关心的问题。随着超高压、特高压线路的建设,对输电线的防雪灾、冰灾提出了更高的要求,因此有必要借鉴超高压电网的运行经验,对输电线覆冰舞动的静态力学特性进行深入的研究。本文首先对四川省凉山地区500kV二滩-自贡输电线路运行十年来的覆冰事故进行相关现场调研和统计分析,得出了分裂导线在高海拔、重冰区发生覆冰事故的特点和规律:覆冰事故主要发生在30mm冰区以上的重冰区,其后果是造成大量绝缘子和间隔棒的损坏,其原因是分裂导线的覆冰舞动和脱冰跳跃;接着分析了高海拔山区分裂导线的空气动力效应,得出由于尾流效应,分裂导线较单根导线而言,不仅较易发生舞动,且舞动时伴有很强的纵向和横向运动,此外由于间隔棒的约束还易引发导线的翻转,因而危害较大,但微风振动危害较小,并可通过加装减振器进一步降低其危害。根据直接平衡法,推导了分裂导线的基本动力学体系——导线段静平衡控制微分方程、动态位移控制微分方程及导线段的静态有限元方程,其后,运用无抗弯导线段的控制微分方程,得出了有覆冰情况下的加装有间隔棒及防舞器的导线的静态构形和张力的解析表达式,可据此求出导线构形与张力的大致分布,应用于工程实例,可对间隔棒的布置、防震锤的选择作出参考。最后,分析了线路参数对导线抗覆冰扭转的影响,并通过对覆冰事故实例的分析和计算,得出了提高导线覆冰扭转稳定性的工程措施。鉴于输电线路舞动的复杂性,为了解决工程实践中采取何种措施可防止覆冰舞动的问题,设计了基于改进BP神经网络的防舞动专家系统,为防舞动措施的设计提出了一些新的思路。更多还原

【Abstract】 Along with the development of Extra-high Voltage (EHV) and Ultra-high Voltage (UHV) transmission lines as well as the increase of the long-span transmission lines, the harms of icing-caused galloping and ice-shedding jumping in overhead transmission lines were extensively concerned. It is necessary to make a deep investigation and study in accordance with experience in the operation of EHV electric network.Analysis of site investigations and accidents were carried out in view of the galloping and ice-shedding of 500kV overhead transmission lines from Ertan to Zigong in the Liangshan area. The characteristics and laws of occuring accidents due to the galloping and ice-shedding of overhead transmission lines were summarized in high altitude area with serious ice covering.Furthermore, the effect of aerodynamics and the vibration characteristics as well as the stabilization calculation on bundled conductor line with galloping and ice-shedding were researched,Finally ,the analytical studies performed at Ontario Hydro can be used to conduct a parametric study of the Er-Zi lines. Furthermore, the related measures to improve the torsional stability for overhead transmission lines were proposed by the analysising of several accidents in this paper. After the increase in number of spacers, the torsional stability is increased. The resistance of the bundle to overturning can be increased by means other than spacer dampers, namely increasing the subconductor tension difference, lowering the center of mass of the bundle( by adding weights), and the installation of horizontal interphase spacers.更多还原