设计简介
摘 要
随着电力工业的发展和电力市场的提高，不间断送电的可靠性越来越受到重视。在现代电力系统中，为满足电网经济运行及可靠供电，电网接线一般使用闭环设计，开环运行，在开环运行的变电站装设备用电源自动投入装置，当主供电源发生故障时，备用电源自动投入，从而立即恢复对用户的供电。本文在对供电企业应用的备用电源自动投入装置的现状以及运行中关心的问题分析的基础上，进行了备用电源自动投入装置的功能实现研究。
首先，给出了备用电源自动投入装置的实现原理；然后设计了自投装置的软件部分。接着深入分析了自投的实现过程。最后，考虑到备用电源自动投入装置一次接线方式较多，有多种运行方式，为适应不同现场的需求，采用了梯形图编程的方法用于开发备用电源自动投入装置。梯形图程序是由梯形图图元按一定的语法规则组合成的、可以表达一定布尔逻辑关系的程序语言，通过改变装置内部的梯形图程序，来适用于不同的各自投方式，实现备自投的动作过程。通过对梯形图编辑环境的语法规则的分析和分段自投动作梯形图的示例，展示了梯形图对适应不同现场多种运行方式的优越性，表明了梯形图可大大提高装置的灵活性和适用性。
关键词：PLC，各自投,备用电源,梯形图
ABSTRACT
With development of the power industry and the power market，more and more attention has been given to the reliability of the uninterrupted power transmission．In modern power systerns，to satisfy the economic operation of network and ensure the reliable power supply,network connection,generally,is designed as the closed loop and operates as the open loop．At the substation with open loop operation,where backup power switchover unit is installed，in case of the main power faults，the backup power will automatically input，thus the power supply for users will be immediately restored．
Based on analysis on the current status of the backup power switchover unit applied by power companies and operation problems involved，the thesis has studied the function realization of the backup power switchover unit．
Firstly,the thesis has put forward the realization theory of the backup power switchover unit；secondly,it has designed the software of the backup power switchover unit；thirdly,it has thoroughly analyzed the realization processes of the backup power switchover；finally,in view of the various primary connection methods and various operation methods of the backup power switchover unit，it has used the ladder program for the development of the backup power switchover uint in order to meet requirements of different spots．The ladder program,combined by the ladder symbols according to the grammatical rules，can express the program language of Boolean logic relation，and apply the different backup power switchover methods to realize the action process of the backup power switchover．Through the analysis on the grammatical rules of the ladder editing surroundings and the demonstration of the sectional backup power switchover action ladder,the thesis has displayed the superiority of the ladder suiting various operation methods of different spots，and shown that the ladder can greatly improve the flexibility andapplicability of the unit．
Key words: Reserve Power Supply Automatic Connection Device，backup power,Ladder
目 录
摘 要 I
ABSTRACT II
第一章 绪论 1
1.1 研究背景 1
1.2 本课题研究解决的问题 1
1.3 本课题研究解决的主要工作 2
1.4 本章小结 2
第二章 备用电源自投装置的原理 3
2.1 备用电源和设备自动投入的基本概念 3
2.2备用电源自动投入装置遵循的基本要求 3
2.3 备用电源的备用方式 4
2.3.1 明备用的控制 5
2.3.2暗备用的控制 5
2.4 备用电源自投装置存在的缺陷及应对措施 6
2.5本章小结 7
第三章 备用电源自动投入装置的硬件电路设计 8
3.1备用电源自动投入的系统框图 8
3.2 硬件结构图 8
3.3 PLC选型 10
3.3.1 PLC型号选择及I/O端子分配 10
3.3.2 FX2N系列可编程程序控制器的基本组成 10
3.3.3 三菱FX2N-128MR-001与 FX2N-8AD特点简介 10
3.4 PLC的输入输出接线图 10
3.5 继电器控制原理 14
3.6 断路器控制原理 15
3.6.1 本方案的暗备用工作原理分析 17
3.6.2 本方案的明备用工作原理分析 17
3.7本章小结 18
第四章 备用电源自动投入装置的软件设计 19
4.1 程序设计流程图 19
4.2 程序设计梯形图 21
4.3 工作原理分析 24
4.4本章小结 26
总结 27
致 谢 28
参考文献 29
