瑞安高新区35KV降压变电所电气一次部分初步设计

摘要

变电所是电力系统中对电能的电压和电流进行变换、集中和分配的场所。为保证电能的质量以及设备的安全，变电所还应进行电压调整、无功补偿、潮流控制，并保障输配电线路和主要电气设备的正常运行。所以变电所电气一次部分的初步设计就显得尤为重要，它是建设一个变电所的关键环节。

    本文首先根据系统原理图与所有负荷的参数，对原始资料进行分析和负荷计算，并由此确定了主变压器台数，容量及型号。接着，从安全，经济及可靠性方面考虑，确定了35kV和10kV的主接线方式。最后，根据最大持续工作电流及短路计算的计算结果，对高压断路器，隔离开关，母线，绝缘子和穿墙套管，电流互感器，电压互感器，避雷器进行了选型并根据动稳定性和热稳定性对其进行校验，从而完成了35kV变电所电气一次部分的初步设计。

关键词：变电所；变压器；主接线；电气设备选型

目录

摘要······················································3

第1章设计任务书·········································6

1.1设计题目··········································6

1.2变电所基本资料····································6

1.310kV用户负荷统计资料······························6

1.4变电所与电力系统的连接情况························6

1.5设计任务··········································6

1.6设计中采用的原始资料及数据························6

第2章无功补偿与负荷的计算·······························8

2.1无功补偿与负荷的计算······························8

   2.1.1无功补偿的计算·······························8

   2.1.2负荷计算·····································9

2.2主变压器容量的计算································11

2.3所用变压器容量的计算·····························11

第3章变电所主电路的设计·································13

3.1变电所电气主接线的设计····························13

   3.1.1主接线设计的依据·····························13

   3.1.2主接线设计的基本要求·························13

   3.1.3变电所主接线设计的基本原则···················13

   3.1.4变电所6—10kV侧短路电流的限制···············14

   3.1.5主接线中的设备配置···························14

3.2电源进线选择与比较·······························15

3.3变电所主变压器的选择与确定·······················19

第4章电气设备的选择····································20

4.1电气设备的选择···································20

   4.1.1断路器的选择·································20

   4.1.2隔离开关的选择·······························21

   4.1.3母线的选择···································21

4.2配电装置的选型···································22

   4.2.1概述········································22

   4.2.2外配电装置的安全净距························23

4.3互感器的配置·····································23

4.4继电保护的设计···································24

4.5直流系统·········································24

4.6测量表记·········································25

4.7电缆设施及电缆···································25

4.8防雷接地设计·····································25

   4.8.1雷电的危害···································25

   4.8.2变电所的防雷保护·····························25

   4.8.3接地装置的作用·······························26

参考文献················································27

致谢····