中文摘要

针对目前运行的大型电力变压器冷却控制装置存在的控制回路复杂、可靠性

低、故障率高、控制误差大等问题，提出并研制了一种新型的变压器强迫油循环风

冷控制装置。装置以西门子S7－200（CPU224）型PLC作为控制器构建了变压器冷

却控制系统；系统以变压器顶层油温为被控量，提出了有差值裕度的投、切温度阀

值的控制策略；提出了按冷却器的持续运行和累积运行时间自动均衡投切冷却器的

控制方法；此外装置还具有通信及远方监视、故障定位、信息显示等功能。目前，

装置已经在福建漳州莆美、角美220kV变电站投入使用。运行表明，该装置可靠性

高、控制精确、并能延长冷却器组寿命，满足了大型变压器冷却控制装置智能化控制

的要求。

关键字：变压器，冷却控制系统，可编程序控制器，负反馈控制

Abstract

To the problem exit in the cooling control device for large capacity transformer,

such as the complicated control circuit,low reliability,high fault rate,large control error,

the principle and implementation of a cooling control device for forced oil-circulated

air-cooled large capacity transformer based on PLC is presented in this paper.The device

use siemens S7-200 PLC(CPU224)as controller,construct the cooling control system for

transformer;the transformer temperature as the control system’s controlled variable,use

control strategy of switch on and off value,which have margin in them,combine the

accumulate operating time and continual operating time of cooling units,realize

balanced,integrated auto control of cooling device.Beside this,the device has other

functions such as,communication and remote surveillance,fault locating,information

display.The devices have been used in Pumei and Jiaomei 220kV transformer substation,

Zhangzhou,Fujian province.The results of operations show that the device is of high

operation reliability,accurate control,can prolong the service life of the cooling unit.

The requirements of the intelligent control for large capacity transformer cooling device

are satisfied.

Li Huabo(School of electric engineering)

Directed by prof.Liu Zongqi

KEY WORDS:transformer,cooling control system,PLC,negative feedback control华北电力大学硕士学位论文

目录

中文摘要

英文摘要

第一章引言...........................................................1

1.1论文的背景和意义.................................................1

1.2冷却控制装置研究现状.............................................2

1.3课题研究工作......................................................2

第二章强迫油循环冷却及控制系统运行分析...............................4

2.1强油循环风冷却器及控制器的结构和工作原理........................4

2.1.1风冷却器....................................................4

2.1.2风冷控制装置................................................5

2.1.3现行大型变压器冷却装置的配置和特点.........................7

2.1.4风冷却器控制线路存在的问题.................................7

2.2大型油冷变压器发热和散热计算.....................................8

2.2.1变压器损耗计算..............................................8

2.2.2变压器散热方式..............................................9

2.2.3变压器散热计算..............................................9

第三章冷却控制装置的功能和控制方法..................................12

3.1电力变压器运行规程中关于冷却控制的规定.........................12

3.1.1对变压器的冷却装置的要求..................................12

3.1.2变压器温度限值.............................................12

3.1.3强迫油循环冷却变压器的运行条件............................12

3.2变压器冷却控制装置的功能设计....................................13

3.3冷却控制装置功能模块设计........................................14

3.4控制方法和策略研究..............................................15

3.4.1变压器油温自动控制的控制方法..............................16

3.4.2综合投、切控制策略.........................................16

3.4.2.1控制策略原理...........................................17

3.4.2.2控制参数的整定.........................................17

3.4.3按运行时间投切的控制方法..................................18

第四章冷却控制装置的硬件设计........................................20

4.1电气元件及在装置中的应用........................................20

4.1.1凝露温度监控器.............................................20

4.1.2电动机保护器...............................................21

4.1.3开关器件...................................................21

1华北电力大学硕士学位论文

4.2可编程序控制器..................................................21

4.2.1可编程序控制器的输入输出..................................22

4.2.2可编程序控制器的选择.......................................23

4.3装置电气连接.....................................................24

4.3.1电源监控和凝露温度监控部分电气接线........................24

4.3.2冷却器电动机保护控制电气接线..............................26

4.3.3可编程序控制器的输入输出连接..............................27

4.3.3.1 CPU224的输入输出连接.................................27

4.3.3.2 EM223的输入输出连接..................................29

4.3.3.3 EM221和EM222的输入输出连接...........................30

4.4通讯连接.........................................................31

第五章软件设计......................................................32

5.1可编程序控制器编程..............................................32

5.1.1软件总体设计...............................................32

5.1.2电源和三侧开关处理.........................................34

5.1.3投入计时处理、超时和切除计时处理..........................35

5.1.4投切判断和投切处理.........................................35

5.1.5通讯处理...................................................36

5.2上位机监视软件设计..............................................37

5.2.1监视软件总体设计...........................................37

5.2.2串口设置和打开.............................................38

5.2.3线程的建立及串口数据的读取、解析和显示....................39

结论和展望...........................................................41

1结论...............................................................41

2展望...............................................................41

参考文献..........................................................43

致谢.................................................................46

在学期间发表的学术论文和参加科研情况.................................47基于PLC的大型电力变压器冷却控制装置的研究