220kV大截面电缆结构设计

220kV大截面电缆结构设计

摘要

随着中国经济的快速发展，城市现代化水平的不断提高，电力电缆作为城市电网中的重要设备，发展速度极快，平均年增长量达到百分之三十五。近几十年来，电能需求量的不断增长，远离工业中心的大型水电站的开发，更需远距离输送电能，使输电电压水平迅速上升。交联聚乙烯绝缘电力电缆以其合理的工艺结构，优良的电气性能和安全可靠的运行特点，近年来在国内外获得了迅猛的发展。尤其在高压输电领域更取得了巨大的发展。超高压、大长度、大截面和高可靠性已成为当今电力电缆技术发展热点。在这里介绍了高压大截面电缆的用处，高压大截面电缆的在国内外的应用，并举出了实例，描述了高压大截面电缆的发展前景。对220kV2500mm2的电缆进行了设计，2500mm2截面的电缆线芯采用的是分割导体，详细的计算了电缆的绝缘厚度、缓冲带、纵向阻水层、绝缘屏蔽、金属护套和外护套的外径厚度尺寸。并计算了电缆的电气参数，其中有导电线芯直流电阻的计算，电缆交流电阻的计算，电缆绝缘电阻的计算，电缆电容的计算，电缆电感的计算，绝缘介质损耗的计算，金属护套损耗的计算，电缆各部分热阻的计算，电缆连续允许载流量的计算以及电缆允许短路电流的计算。

关键词 220kV；大截面；电缆；应用；设计

220kV large cross-section cable structure design

Abstract

Along with the rapid development of China's economy, City modernization level unceasing enhancement, power cable in the grid as a city of important equipments, the speed of development fast, average annual growth reached thirty-five percent. In recent decades, the growing demand for electricity, away from the center of the industry development of large hydropower station, need more to long-distance transmission of electricity, make the transmission voltage level up rapidly. Crosslinked polyethylene insulated power cables with its reasonable technical structure, excellent electrical properties, safe and reliable operation characteristics, in recent years at home and abroad and the development of the obtained rapidly. Especially in the high voltage electricity field in more made great development. High pressure, big length, large cross-section and high reliability has become the power cable technology development hot spots. Here introduces the high voltage large cross-section cable use and the high pressure large cross-section cable in the application of both at home and abroad, and the examples,describe the high pressure large cross-section cable development prospects.In 220 kV2500mm2 cable to carry on the design, 2500 was the section cable core USES is the segmentation conductor,

Keywords 220kV; Large cross-section; cable；application；design

目录

摘要 ...................................................................................................................... I Abstract ............................................................................................................... II

第1章 绪论 ........................................................................................................ 1 1.1 课题背景 .................................................................................................. 1 1.2 大截面电缆在国内外的应用 .................................................................. 1 1.3 设计内容 .................................................................................................. 2 第2章 220kV2500mm2电缆结构 ....................................................................... 3 2.1 分割导体的股块构成。 .......................................................................... 4 2.1.1 2500mm2五芯分割导体结构设计及制作 ......................................... 5 2.1.2分割导体关键参数的选取和设定 .................................................... 5 2.1.3填充系数的选取和成缆外径的设定： ............................................ 5 2.1.4计算单个股块的截面积SA ................................................................ 6 2.1.5单线直径选取。 ................................................................................ 6 2.2 绝缘厚度的确定 ...................................................................................... 7 2.2.1 按照冲击场强计算绝缘厚度 ........................................................... 7 2.2.2 按工频场强计算绝缘厚度 ............................................................... 8 2.3 缓冲带和纵向阻水层结构确定 .............................................................. 9 2.4 绝缘屏蔽层 ............................................................................................ 10 2.5 金属护套的选择 .................................................................................... 10 2.5.1 金属护套的种类 ............................................................................. 10 2.6 金属护套选用的一般原则 .................................................................... 11 2.7 外护套选择 ............................................................................................ 12 2.8 基本参数 ................................................................................................ 12 第3章 220kV2500mm2电缆各参数的计算 ...................................................... 14 3.1 导电线芯的直流电阻 ............................................................................ 14 3.2 电缆的交流电阻 .................................................................................... 14 3.3 电缆的绝缘电阻 .................................................................................... 15 3.4 电缆电容 ................................................................................................ 15 3.5 电缆的电感 ............................................................................................ 16 3.6 绝缘介质损耗 ........................................................................................ 17 3.7 金属护套损耗 ........................................................................................ 17 3.8 电缆各部分热阻计算 ............................................................................ 18 3.8.1 绝缘热阻T1 ..................................................................................... 18