数字高压兆欧表设计.doc

摘要

在工业生产过程中，为保证设备生产安全，在低压电气装置的实验中，常温下，电动机、配电设备等装置的绝缘电阻常常都有要求，一般不得低于0.5兆欧，我们统称这样的电阻为绝缘电阻。绝缘电阻作为设备电路中的重要参数之一，为满足测量的准确性，因此要设计高精度的兆欧表。兆欧表也叫绝缘电阻表，是测量绝缘电阻最常用的仪表。兆欧表主要用于测量电力设备的绝缘电阻，判断设备绝缘是否合格，然后决定该设备是否进行绝缘性能试验和耐压试验，为后续试验提供安全保障。原来的绝缘电阻测量设备是以半机械式的兆欧表为主，其测量精度差，显示阻值低等缺点限制了其使用范围。随着电子产品的普及，传统仪表中的的机械电子线路以慢慢被以单片机为主体的新型智能化仪表所代替。这种改变可以容易地将先进计算技术与精确地测量控制技术结合在一起，形成新型智能化测量仪表，也就是我们所说的数字兆欧表。这种新型的智能化仪表以其测量自动化、高精度测量的特点，更多的应用于生产中。
本论文从兆欧表的背景意义以及国内外的研究现状出发，按照生产所需设计了整个过程。包括直流高压模块的设计、取样电路的设计、采用单片机MSC1210的模拟信号采集与转换以及数据处理电路、数据显示电路四部分；还包括采用Protel 出的原理图和软件编程部分。
关键词：绝缘电阻；直流高压模块；数据采集与处理；单片机MSC1210
Abstract

To ensure the equipment production safety, device insulation resistance often have requirements, that general shall not be lower than 0.5 M in the experiments, which under normal temperature,so we collectively referred to as insulation resistance. Insulation resistance as one of the important parameters equipment circuit, digital high-voltage megohmmeter is design for meeting the accuracy of determination. Megohmmeter which also called insulation resistance meter, is the most common measuring insulation resistance meter.Megohmmeter mainly is used for measuring power equipment insulation resistance, judgeing equipment, and then decide whether qualified insulation on the device is insulation performance test and pressure test, to provide security for the follow-up tests.The original insulation resistance testing equipment is half mechanical megohmmeter primarily, which limits its usage scope with lowing measurement precision and showing the low resistance.
With the popularization of electronic products, the traditional instruments of mechanical electronic circuit is being slowly replaced by new intelligent instrument which mainly isbased on the body of single chip. This change will be easy to combine the advanced technology and the accurate calculational measure control technology combining together, forming the new intelligent measuring instrument and that is what we called digital Megohmmeter。This new type of intelligent instruments can be widely used. in the process automation, for the improvement in automatic measurement,  the accuracy of measuring results data.
This article based on a brief introduction of Megohmmeter on the domestic and international development situation, tells the design of the entire process based on meeting the production.The process includes two parts :hardware design and software design.Hardware design generated mainly by the DC high voltage circuit, sampling circuit, data acquisition and controller, Digital tube display four major components, Software section contains a principle diagram with Protel and programming parts.
　　　Keywords: insulation resistance; Dc high voltage module; Data acquisition and processing; single-chip computer MSC1210.
目 录
摘要 I
Abstract III
目 录 I
第一章 绪论 1
1.1 绝缘电阻测量的意义 1
1.2 绝缘电阻测试仪器的发展 1
1.2.1 绝缘电阻测试仪器的发展史 1
1.2.2 国内外的发展现况 2
1.3 本论文主要内容和结构 2
第二章 系统总体设计思想 5
2.1 系统要实现的功能 5
2.1.1数字高压兆欧表要实现的功能和性能 5
2.1.2系统功能模块的划分 5
2.2 主要技术选择 5
2.3 系统总体结构设计 7
2.4 本章小结 8
第三章 系统硬件设计 9
3.1 直流高压产生电路设计 9
3.1.1 多谐振荡的设计 10
3.1.2 变压器的设计 12
3.1.3 倍压整流电路的设计 13
3.1.4 电路其他器件的设计 16
3.2 取样电路设计 18
3.3 模拟信号采集与转换以及数据处理电路设计 20
3.3.1 A/D转换器的选择 20
3.3.2 放大器的选择 22
3.3.3 MSC1210的介绍及其口线分配 22
3.3.4 晶振和复位电路的设计 24
3.4 数码管显示电路设计 26
3.5 本章小结 28
第四章 系统软件设计 29
4.1 系统总流程设计 29
4.1.1 通道选择软件设计 31
4.1.2 数据采集模块软件设计 32
4.2 数据采集与处理及数码管显示程序 33
第五章  总结 39
参考文献 40
致 谢 42
附录一 43
设计总电路图 43
附录二 44
设计总原理图 44