输电线路直流融冰时间的计算和试验验证.docx

输电线路直流融冰时间的计算和试验验证范松海，刘馨，聂鸿宇，刘睿(四川电力科学研究院,成都610072)Experimental Investigation of Ice-Melting and its Temperature Characteristic of Iced Conductor with DC FAN Songhai, LIU Xin, NIE Hongyu, LIU Rui(Sichuan Electric Power Research Institute, Chengdu 610072)摘要： 2008年初中国南方发生大面积冰灾之后，中国一直在研发输电线路直流融冰技术。为防止导线上冰荷载过重而造成电网冰灾事故，需根据规定的融冰时间安排融冰设备。因此，融冰时间的估算是制定直流融冰方案的必要环节。本文根据导线融冰的物理过程，分析了融冰过程中冰层在重力作用下逐步下移以及其与导线之间气隙的增长过程，首次提出了椭圆形气隙－冰层界面移动融冰模型，并在人工气候室中对模型的计算结果进行了试验验证。结果表明，在融冰过程中明，随着冰层的融化，融冰水从空隙流失，冰和导线之间将形成椭圆形的气隙；融冰时间主要受电流密度、风速、环境温度以及冰厚等因素的影响。关键词：冰灾；输电线路；融冰电流密度；融冰时间Abstrac: Ice-melting with direct current (DC) is one of the key technologies to prevent Chinese power grid from ice-storm. Especially after the severe ice storm in the southern part of China in early 2008, DC ice-melting technology has drawn much more attention than ever before. However, there are few satisfactory methods to select correct parameters, so the ice-melting project rarely achieve desired effect in some cases when applied in Hunan, Guizhou and other provinces in China sometimes. Therefore, it is of great significance to develop a method to estimate parameters which is applicable in the practical situation for DC ice-melting. To handle this, the factors such as wind velocity, ambient temperature, current density and ice-layer thickness were analyzed and then a DC ice-melting model is put forward in this paper. Both the results of simulations and experiments show that the ice-melting process can be divided into three stages composed of temperature rising, ice melting and ice shedding, among which the ice melting is the key stage costing most of the ice-melting time. In this stage, an elliptic air-gap is formed and widened gradually with influence on both the ice-melting time and the temperature of conductor. The experiments in the artificial climate chamber demonstrate that the results of the presented model are consistent with those of the experiments generally, so it can be employed to estimate the parameters