某学校供电及保护系统设计

摘 要

变电站在整个电力运输的过程中有着不可或缺的地位。简单地说，从发电厂发出的高压电到客户用的低压电，没有变电所，这个过程是不可能实现的。下面，简述一下本次毕业设计需要注意的步骤：本次设计是某学校的供电及保护系统设计，要完成本次毕业设计就必须先了解这个学校的负荷工作情况，在哪些区域的负荷比较大，那个区域的负荷工作最重要。其次，还需要了解的是这些负荷之间的电气主接线以及变压器的分布情况。

在设计主接线的时候，必须要要进行短路计算及其它的保护线路。避免由于小面积的短路而造成一些比较大的麻烦。必要的的时候，可以进行分段或者分级保护。在选择电气设备时，需要考虑的因素是经济、节能、安全可靠。另外就是，选择合适的电气设备是依据自身的需求，既不能额定负荷功率过小，造成用电荒，也不能额定运行功率过大，而造成资金的比必要浪费。

保护线路，是依据负荷的等级从而有所不同。通常只会采取分级保护，如果有必要还会采取分段保护。

配电站的分配电能，取决于每个区域的负荷功率的大小。配电站的下一个步骤就是变压器，它是把高电压转变成负荷的额定电压。

从变电站买进电，然后进到自己的配电所，分配电能，到各个区域的变压器，由变压器向负荷直接供电。这样就会形成整个学校的供电网络。其中会涉及到电气设施的选择、保护以及整个供电网络的保护等。

关键词：变压器 ;保护 ;安全可靠; 主接线

Abstract

Substation plays an indispensable role in the whole process of electric transport in. Simply speaking, from the power plant to customers with the high voltage low voltage, no substation, this process is not possible. Below, introduce the graduation design need to pay attention to the steps: This design is the design of power supply and protection system of a school, to complete the graduation design, we must first understand the work load of the school, in which the regional load is relatively large, the most important load in the area. Secondly, also need to know is the load between the main electrical wiring and distribution transformer.

In the design of the main wiring, must be short circuit calculation and protective circuit of the other. To avoid the short circuit of small area caused by the relatively large number of trouble. When necessary, can be segmented or classified protection. In the choice of electrical equipment, consideration is the economic, energy saving, safe and reliable. In addition, select the appropriate electrical equipment according to their own needs, neither the rated load power is too small, resulting in a shortage of power, also rated power can not be too large, resulting in the waste of money than necessary.

The protection circuit is based on the load level, which is different. Usually adopt grading protection, if necessary, will take the segment protection.

The electric distribution station, load power depends on the size of each region. The power station the next step is the high voltage transformer, it is converted to the rated voltage of the load.

Buy electricity from the substation, and then into their distribution, distribution of power transformer, to each area, from the transformer to the direct power supply load. The power supply network which will form the whole school. Which involves the choice of electrical facilities, as well as the protection of the power supply network Key Words： Safety main wiring transformer protection

目 录

摘要 ...................................................................Ⅰ Abstract ............................................................... Ⅱ 1. 绪论 ................................................................. 1 2. 负荷计算 ............................................................. 2

2.1 负荷计算的有关内容 ............................................. 2 2.2 负荷计算的过程 ................................................. 2 3. 变压器的选择 ......................................................... 5

3.1 主变压器的确定 ................................................. 5 3.2 补偿电容器的选择 ............................................... 6 4. 电气主接线的选择 .................................................... 7

4.1 电气主接线的设计要求与设计原则 ................................. 7 5. 短路电流计算 ......................................................... 9 5.1 短路的类型 ..................................................... 9

5.2 短路电流的计算 ................................................ 10 6. 主要电气设备的选择及校验 ............................................ 15

6.1 选择条件 ...................................................... 15 6.2 高压设备的选择 ................................................ 16 6.3 35kv电缆进线柜的主要设备校验 .................................. 17 6.4 35kvJDZX－35电压互感器的校验 .................................. 19 6.5 低压侧设备选择及校验 .......................................... 21 7. 防雷与接地 .......................................................... 24 7.1 防雷保护措施 .................................................. 24 7.2 接地种类 ...................................................... 25 8. 供电系统的继电保护 .................................................. 26

8.1 概述 .......................................................... 26 8.2 保护的设置 .................................................... 27 总结 ................................. …… 此处隐藏：8530字，全部文档内容请下载后查看。喜欢就下载吧 ……