输电线路地线融冰的热平衡分析与计算  

Heat Balance Analysis and Calculation of Ground Wire Ice-Melting in Transmission Line

作　　者：李铁鼎 李健[1] 吕健双[1] 黄欲成[1] 

机构地区：[1]中南电力设计院,武汉市430071

出　　处：《电力建设》2015年第4期70-76,共7页Electric Power Construction

基　　金：中国电力工程顾问集团科技项目(DG1-D03-2013)

摘　　要：根据我国电网覆冰的现状,结合国内外融冰的实践经验,在分析地线融冰机理的基础上,结合传热学的原理,建立椭圆融冰的数学计算模型,从工程应用的角度出发,研究最小融冰电流的计算方法。通过计算LBGJ-100-20AC、LBGJ-120-20AC、LBGJ-150-40AC这3种铝包钢绞线的地线融冰电流,分析覆冰厚度、风速、环境温度以及融冰时间等因素对地线融冰的影响;计算不同地线材料与融冰电流的关系;最后,通过该文提出的计算模型计算目前输电线路工程常用地线材料的最小融冰电流。计算结果与目前工程应用较多的布尔斯道尔夫融冰电流计算公式对比,发现2种方法的计算结果吻合较好。分析计算结果表明:在架空输电线路直流融冰过程中,融冰电流是由覆冰厚度、环境温度、风速和地线材料等参数共同决定,其中,环境温度、覆冰厚度和地线材料对地线短路电流融冰均有显著影响,但风速的影响相对较小。该文提出的融冰电流计算模型,为输电线路地线融冰电流的选择及融冰装置的设计,提供了有效的参考。According to the present situation of ice cover of pow er system in China,combined w ith the practical experience of ice melting at home and abroad,this paper analyzed the mechanism of ground w ire ice melting. On this basis,an elliptic mathematical calculation model w as set up for ice-melting,combined w ith the theory of heat transfer. In the light of the engineering application,the calculation method of minimum ice-melting current w as studied. Through the ice-melting current calculation of three kinds of aluminum clad steel w ires（ LBGJ-100- 20 AC,LBGJ-120- 20 AC,LBGJ-150-40AC）,this paper analyzed the impact of ice thickness,w ind speed,ambient temperature,ice melting time and other factors on ground w ire ice-melting; calculated the relationship betw een different w ire materials and ice melting current.Finally,the proposed calculation model w as used to calculate the minimum ice-melting current of ground w ire materials commonly used in transmission line engineering. Through the comparison of the calculation results w ith those results of Bauers Dolf ice-melting current calculation formula w hich w as commonly used in transmission line engineering,it show s that tw o kinds of calculation results are in good agreement. The analysis and calculation results show that the ice-melting current is determined collaboratively by ice thickness, ambient temperature, w ind speed and ground w ire material; ambient temperature,ice thickness and ground w ire material all have obvious influences on the ground w ire ice-melting current,but the influence of w ind speed is relatively small. The proposed calculation model of ice-melting current can provide useful and valid reference for the selection of ground w ires ice-melting current and the design of defroster.

关 键 词：输电线路 地线融冰 热平衡 椭圆融冰模型 工程应用 

分 类 号：TM755[电气工程—电力系统及自动化]