国泰220kV一次降压变电所电气部分设计
中文摘要
本文主要对国泰220kV一次降压变电所电气部分进行设计，根据任务书的要求，设计的主要内容包括主变选择、电气主接线的拟定、短路计算、电气设备选择、配电装置的规划、继电保护和自动装置的规划以及防雷保护的规划等主要工作。本文中对主变的选择、电气主接线的拟定、配电装置的规划、继电保护和自动装置的规划进行了详细的说明，特别是对主变继电保护的规划、动作原理等内容进行了深入的研究和思考。本文重点的计算部分包括短路计算、设备的选择校验计算、和避雷针的保护范围计算等部分。其中短路计算包括对称短路计算和不对称短路计算两部分，分别应用了计算曲线和正序等效原则；防雷计算中采用了等针高的计算方式。
本次设计既满足了电力系统的安全、经济、可靠、环保的基本要求，又重视了电力系统的长期规划长远的发展，注重了解和应用电力系统的新技术新设备，变电所进行设计，是一次较为综合性的实践过程。是对以往所学专业知识的系统总结和提高。本设计属于变电所电气部分初步设计，能够基本满足任务书和毕业论文的总体要求。
关键词 变电所，电气系统，短路计算，电气设备
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沈阳工程学院毕业设计
Abstract
In this paper The professional graduate in system in electric power design is once more synthesize of training, it is we will during the period of school a profession for learning knowledge proceed theories and practice very good combination, make use of the theories knowledge proceeds with a profession for learning technical ability engineering design with science study. This graduate design thesis is a 220 kV declining to press to change to give or get an electric shock an electricity parts of first steps design. For the sake of dependable that guarantee the power supply with a request that contented long-term burthen, carries according to the forward the programming proceeding design developments, from but guarantee to change to give or get an electric shock can long-term dependable power supply.
This design not only meets the power system security, economic, reliable, basic requirements of environmental protection, but also to the long-term power system planning long-term development, focusing on understanding and application of new technologies and new power system equipment, substation design, is a more integrated practice. Is the knowledge learned in the past and upgrade the system. This design is part of the preliminary design of electrical substations and can basically meet the overall mission statement and these requirements.
Key Word substation，electric power system， short computing，electricity equipment
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国泰220kV一次降压变电所电气部分设计
目录
中文摘要 .......................................................................................................................................... I Abstract .......................................................................................................................................... II 目录 ............................................................................................................................................... III 第一部分 说明书 ........................................................................................................................... 1 1 主变压器的选择 ......................................................................................................................... 1
1.1 主变选择的有关规定 ....................................................................................................... 1
1.2 主变选择的原则 ............................................................................................................... 1
1.2.1 主变台数的确定 ..................................................................................................... 1 1.2.2 变压器形式的选择 ................................................................................................. 1 1.2.3 主变容量的确定 ..................................................................................................... 2 2 电气主接线的选择 ..................................................................................................................... 3
2.1 概述 ................................................................................................................................... 3 2.2 主接线的设计原则 ........................................................................................................... 3
2.2.1 考虑变电所在电力系统中的地位和作用 ............................................................. 3 2.2.2考虑近期和远期的发展规模 .................................................................................. 3 2.2.3考虑负荷的重要性分级和出线回路数多少对主接线的影响 .............................. 3 2.2.4考虑主变台数对主接线的影响 .............................................................................. 4 2.2.5考虑备用容量的有无和大小对主接线的影响 ...................................................... 4 2.3 主接线设计的基本要求 ................................................................................................... 4
2.3.1 可靠性 ..................................................................................................................... 4 2.3.2 灵活性 ..................................................................................................................... 4 2.3.3 经济性 ..................................................................................................................... 5 2.4 主接线的确定 ................................................................................................................... 5
2.4.1 对原始资料的分析 ................................................................................................. 5 2.4.2 主接线方案的拟定 ................................................................................................. 5
3 短路计算 ..................................................................................................................................... 8
3.1 概述 ................................................................................................................................... 8 3.2短路电流计算的主要目的 ................................................................................................ 8 3.3短路计算中的一般规定 .................................................................................................... 8 3.4电路元件参数的计算 ........................................................................................................ 9
3.4.1基准值 ...................................................................................................................... 9 3.4.2各元件参数标么值计算 .......................................................................................... 9 3.4.3标么值表示的等值网络 .......................................................................................... 9 3.5 三相短路电流周期分量计算 ......................................................................................... 10
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沈阳工程学院毕业设计
3.5.1影响短路电流变化规律的主要因素 .................................................................... 10 3.5.2应用计算曲线的具体步骤如下： ........................................................................ 10
4 电气设备的选择 ....................................................................................................................... 11
4.1 概述 ................................................................................................................................. 11
4.1.1 一般原则 ............................................................................................................... 11 4.1.2 选择的一般问题 ................................................................................................. 11 4.1.3 选择项目的说明 ................................................................................................... 11 4.2 高压断路器的选择 ......................................................................................................... 12 4.3 高压隔离开关的选择 ..................................................................................................... 12 4.4 母线选择 ......................................................................................................................... 13
4.4.1软导线介绍 ............................................................................................................ 13 4.4.2一般要求 ................................................................................................................ 14 4.4.3导体截面积的选择与校验 .................................................................................... 14 4.5 电流互感器 ..................................................................................................................... 14
4.5.1参数选择 ................................................................................................................ 14 4.5.2一次额定电流选择 ................................................................................................ 15 4.5.3电流互感器准确级 ................................................................................................ 15 4.5.4热稳定和动稳定校验 ............................................................................................ 15 4.6 电压互感器 ..................................................................................................................... 16
4.6.1 电压选择 ............................................................................................................... 16 4.6.2 准确度选择 ........................................................................................................... 16 4.7 避雷器 ............................................................................................................................. 17
4.7.1 避雷器的参数 ....................................................................................................... 17 4.7.2 避雷器的配置 ....................................................................................................... 17
5 配电装置 ................................................................................................................................... 19
5.1 屋内外配电装置的安全净距 ......................................................................................... 19
5.1.1 概述 ....................................................................................................................... 19 5.1.2 分类及特点 ........................................................................................................... 19 5.1.3 屋内外配电装置的安全净距 ............................................................................... 19 5.2 屋外配电装置 ................................................................................................................. 21 5.3 设计原则 ......................................................................................................................... 21 5.4 设计要求 ......................................................................................................................... 22
5.4.1 满足安全净距的要求 ........................................................................................... 22 5.4.2 施工、运行和检修的要求 ................................................................................... 22 5.5 配电装置形式的选择 ..................................................................................................... 23 6 继电保护及自动化装置规划设计 ........................................................................................... 24
6.1 继电保护在电力系统中的作用 ..................................................................................... 24 6.2 继电保护的基本要求 ..................................................................................................... 24
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