输电线路直流短路融冰的临界电流分析  

Analysis of Critical Ice-melting Current for Short-circuit DC Transmission Line

作　　者：蒋兴良[1] 范松海[1] 胡建林[1] 张志劲[1] 孙才新[1] 

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044

出　　处：《中国电机工程学报》2010年第1期111-116,共6页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2009CB724501);重庆市自然科学基金项目(2008BB6157)~~

摘　　要：根据导线覆冰后短路融冰的物理过程,分析直流融冰的基本条件,通过融冰的热平衡过程分析,建立直流临界融冰条件的物理数学模型,提出计算冰面温度和临界融冰电流的方法,分析影响冰面温度和临界融冰电流的因素,并在人工气候室对建立的模型和提出的方法进行了试验验证,试验结果和计算结果基本吻合。分析计算和试验结果表明:在进行直流短路融冰时,融冰电流必须大于临界融冰电流,并根据覆冰和环境条件合理选择融冰电流;临界融冰电流是冰面温度、导线直径和覆冰厚度的函数,冰面温度决定了临界融冰电流,冰面温度与风速、覆冰厚度、导线直径和环境温度等均有关;覆冰厚度虽对临界融冰电流有影响,但不明显,影响临界融冰电流的主要因素是环境温度和风速。According to the ice-melting process for ice-covered line with short-circuit current method, this paper analyzes the basic conditions of ice-melting. Then based on heat balance analysis of the ice-melting process, a physical and mathematical model indicating the ice-melting critical condition is established, and a method to calculate the ice surface temperature and threshold current is put forward. Then the factors affecting both the threshold current and the external surface temperature of ice-layer are analyzed The model and methods are tested by experiment in ＇artificial climate chamber, and the results of them are basically consistent with each other. Both calculation and experiment show that the ice-melting current should be greater than the threshold current, and should be reasonably selected according to the ice thickness and the environmental conductions. The ice-melting threshold current is a function of three factors as the external surface temperature of ice-layer, the diameter of conductor and the ice thickness. The threshold current is determined by external surface temperature of ice layer, while the later is related to the factors such as wind velocity, ice thickness, conductor diameter and the environment temperature or atmospherical factors. Among them, the atmospherical temperature and wind velocity are the main factors, while the influence of ice thickness is not so obvious.

关 键 词：直流输电线路 融冰 临界电流 冰面温度 

分 类 号：TM852[电气工程—高电压与绝缘技术]