10kV配网电缆温度场和载流量计算分析.pdf

理论研究电工技术
10kV配网电缆温度场和载流量计算分析
张华富,秦波
(1.国网上海电力公司金山供电公司,上海200540:2.上海电力学院,上海200090
摘要:为确保电缆能安全、正常エ作,又充分发挥电缆的输送能力,米用精确方法预计地下电缆的载流量具有重
要意义。针对10kV配网常用三芯电力电缆,结合传热知识对10kV配网直埋电筑温度场进行分析,构造出載流量和
热流密度间的换算关系和边界条件,建立直埋三芯电力电缆的温度场模型,对电缆温度场和载流量进行仿真计算。在
此基础上,基于IEC60857给出的解析计算式进行验证分析,误差不超过0.6%,且与QGDW512-2010《电力电缆
线路运行规程》中规定的载流量值相差不大,误差不超过4%。最后,利用建立的地下直埋电缆温度场模型,分析了
影响土壞直埋电缆载流量的影响因素及各因素对载流量的影响规律,为工程实际提供参考依据。
关键词:配网电缆;解析法;有限元法;温度场;載流量
中图分类号:TM757.3
Calculation an Anlysisi of Temperature Iield and Current Carrying Capacity of
Cables in 10 KV Distribution Network
ZHANG Huafu, QIN Bo
(1. State Grid Shanghai Jinshan Power Supply
Shanghai 200540, Ch
2. College of Flectric Engineering, Shanghai University of Electric Power, Shanghai 200090, China)
Abstract: In order to ensure the safe and normal operation of the cables and give full play to the cable transmission capaci
ty, it is important to predict the current carrying capacity of the underground cable by using an accurate method. For the
three-core cables commonly used in 10 kv distribution network, combined with the heat transfer knowledge, the tempera
ture ficld of the dircct-buricd cables in 10 KV distribution nctwork is analyzed, so as to construct the conversion relation-
ship and boundary conditions bet ween the current carrying capacity and the heat-low density. Then the temperature field
model of the direct buried three-core power cable is established, moreover the temperature field and current carrying ca
pacity of cables are simulated. On this basis, the verification and analysisi are carried out based on the analytical cal
tion formula given by IEC 60837. The error does not exceed 0. 6%, and it is not much different from the current-carrying
value specified in Q/GDW 512 2010"Code of Operation for Power able Line",with the error not exceeding M%. Final
ly, using the established temperature field model of underground buried cable, the influencing factors affecting the current
carrying capacity of direct buried cable and the influence law of each factor on the current carrying capacity are analyzed
which provides a reference for engineering practice.
Key words: cables in distribution network; analytic method; finite clement method; temperature field; current
carrying capacity
0引言
在运行过程中不公因超温而损坏1。电缆正常运行时,
导体的温度取決于坏境温度、土壊热阻系数、空气白然对
随着社会的发展,电力电缆的敷设量在电力系统中所流、敷设方式等条件,而导体允许的长期最高工作温
占的比重越来越大,特別足在城市中心地区,地下电缆化度决定了领定载流量的大小。只有准确确定地下电缆的载
率史足逐提高。电缆在过高温度下工作,将会导致绝缘流量,才能在保证电缆安令运行和使用寿命的前提下尽可
材料川速と化,所以需了解地下散热条件,确保电缆绝缘能提高屯缆的传输容量,获得最大的经济效益。
基金项目:国网上海市电力公司科技项目(編号 SGSHJS
IEC602837标准に-将电缆载流量计算分为损耗计算、
00ECJS1803209)
热阻计算及载流量计算,以热物理性能为基准,可通过解
收稿日期:2019-01-25
析计算获得力也缆的载流量。该算法相对简单,工程
作者简介:张华富(198-),硕士,研究方向为配网电力电缆的用性好,叮粗略估计也缆的载流量。随着数俏计算技术的
维护与运行等。
快速发展,运用计算机来解决工程问题逐渐成为一和主流
201913期13