华北水利水电大学毕业设计(水电厂电气部分初步设计)

摘要

本次设计为水电厂电气部分初步设计，主要讲述了初步设计的基本理论和计算方法，简单介绍了电气设备布置及二次回路方案的规划。主要容分为设计说明书和设计计算书两部分。其中，设计说明书包括五章，分别为（1）电气主接线的论证与确定；（2）厂用电的设计；（3）短路电流的计算；（4）导体与电气设备的选择；（5）电气设备布置及二次回路初步规划。设计计算书包括两章，分别为（1）三相短路电流的详细计算过程；（2）发电厂主要电气设备的选择和校验。

在该次设计中，重点研究问题是电气主接线方案的比较和确定，三相短路电流的计算和发电机引出裸导体与电气设备的选择。最终确定的电气主接线方案为：发电机高压侧采用发电机—变压器联合单元接线，升高电压压侧采用3/2断路器接线，厂用电采用单母线分段接线，厂用高压工作电源从主变压器低压侧引接，厂用备用电源采用暗备用的形式。所选的主要电气设备包括发电机引出裸导体、支柱绝缘子、断路器、隔离开关、电压互感器、电流互感器、保护熔断器、避雷器和消弧线圈。

关键词：水电厂；电气主接线；短路电流；电气设备

Abstract

This preliminary design of electrical part for the hydroelectric power plant mainly narrates the basic theory and calculation method, introduces the arrangement of electrical equipment and the plan of secondary circuit simply. The primary coverage has been divided into two parts: the design instruction booklet and the design account booklet. Among them, the design instruction booklet includes five chapters: (1) the proof and determination of main electrical connection; (2) the design of electricity used by factory; (3) the computation of short-circuit current; (4) the choice of conductor and electrical equipment; (5) the arrangement of electrical equipment and preliminary scheme of secondary circuit. The design account booklet includes two chapters:(1)the detailed computational process of three-phase short-circuit current; (2) the process of main electrical equipment's choice and verification in power plant.

In this design, the key research questions are the comparison and the determination of main electrical connection , the computation of three-phase short-circuit current and the choice of bare conductor and electrical equipment. The main electrical connection determined ultimately is : the side in generator hign-pressur uses generator-transformer joint uint connection; the side of boosting presses uses a 3/2 breaker wiring; single busbar is used in the plant. Hign-voltage power used by plant is drawed from the low pressure side of the connection of the main transformer.

Reserve supply is used in the form of dark alternative. The major electrical equipment selected include bare conductor, pillar insulator, circuit breaker, disconnecting switch, voltage transformers, current transformers, protection fuses, surge arresters and the coil.

Key words: Hydropower plant; main Electrical connection;

Short-circuit current; Electrical equipment

目录

摘要 (Ⅰ)

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

第一篇设计说明书

1 绪论 (1)

2 电气主接线的论证与确定 (3)

2.1 发电机电压接线方式的选择 (3)

2.2 升高电压接线方式的初步选择 (4)

2.3 发电厂主变压器的选择 (9)

2.4 主变压器和发电机中性点接地方式 (11)

3 厂用电的设计 (13)

3.1 厂用电的特点及厂用电的引接 (13)

3.2 厂用变压器的选择 (14)

4 短路电流的计算 (16)

4.1 短路的类型及短路计算 (16)

5 导体与电气设备的选择 (18)

5.1 电气设备选择的一般条件 (18)

5.2 发电机引出裸导体的选择 (19)

5.3 支柱绝缘子的选择 (20)

5.4 断路器的选择 (21)

5.5 隔离开关的选择 (23)

5.6 电压互感器的选择及结果 (24)

5.7 电流互感器的选择及结果 (25)

5.8 保护熔断器的选择 (28)

5.9 避雷器的选择及结果 (29)

5.10 消弧线圈的选择 (30)

6 电气设备布置及二次回路初步规划 (32)

6.1 电气设备布置 (32)

6.2 二次回路的初步规划 (32)

第二篇设计计算书

1 短路电流计算 (34)

2 主要电气设备的选择 (40)