摘要

在工業(yè)生產(chǎn)過程中，為保證設備生產(chǎn)安全，在低壓電氣裝置的實驗中，常溫下，電動機、配電設備等裝置的絕緣電阻常常都有要求，一般不得低于0.5兆歐，我們統(tǒng)稱這樣的電阻為絕緣電阻。絕緣電阻作為設備電路中的重要參數(shù)之一，為滿足測量的準確性，因此要設計高精度的兆歐表。兆歐表也叫絕緣電阻表，是測量絕緣電阻最常用的儀表。兆歐表主要用于測量電力設備的絕緣電阻，判斷設備絕緣是否合格，然后決定該設備是否進行絕緣性能試驗和耐壓試驗，為后續(xù)試驗提供安全保障。原來的絕緣電阻測量設備是以半機械式的兆歐表為主，其測量精度差，顯示阻值低等缺點限制了其使用范圍。隨著電子產(chǎn)品的普及，傳統(tǒng)儀表中的的機械電子線路以慢慢被以單片機為主體的新型智能化儀表所代替。這種改變可以容易地將先進計算技術與精確地測量控制技術結合在一起，形成新型智能化測量儀表，也就是我們所說的數(shù)字兆歐表。這種新型的智能化儀表以其測量自動化、高精度測量的特點，更多的應用于生產(chǎn)中。
本論文從兆歐表的背景意義以及國內外的研究現(xiàn)狀出發(fā)，按照生產(chǎn)所需設計了整個過程。包括直流高壓模塊的設計、取樣電路的設計、采用單片機MSC1210的模擬信號采集與轉換以及數(shù)據(jù)處理電路、數(shù)據(jù)顯示電路四部分；還包括采用Protel 出的原理圖和軟件編程部分。
關鍵詞：絕緣電阻；直流高壓模塊；數(shù)據(jù)采集與處理；單片機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 錄
摘要 I
Abstract III
目 錄 I
第一章 緒論 1
1.1 絕緣電阻測量的意義 1
1.2 絕緣電阻測試儀器的發(fā)展 1
1.2.1 絕緣電阻測試儀器的發(fā)展史 1
1.2.2 國內外的發(fā)展現(xiàn)況 2
1.3 本論文主要內容和結構 2
第二章 系統(tǒng)總體設計思想 5
2.1 系統(tǒng)要實現(xiàn)的功能 5
2.1.1數(shù)字高壓兆歐表要實現(xiàn)的功能和性能 5
2.1.2系統(tǒng)功能模塊的劃分 5
2.2 主要技術選擇 5
2.3 系統(tǒng)總體結構設計 7
2.4 本章小結 8
第三章 系統(tǒng)硬件設計 9
3.1 直流高壓產(chǎn)生電路設計 9
3.1.1 多諧振蕩的設計 10
3.1.2 變壓器的設計 12
3.1.3 倍壓整流電路的設計 13
3.1.4 電路其他器件的設計 16
3.2 取樣電路設計 18
3.3 模擬信號采集與轉換以及數(shù)據(jù)處理電路設計 20
3.3.1 A/D轉換器的選擇 20
3.3.2 放大器的選擇 22
3.3.3 MSC1210的介紹及其口線分配 22
3.3.4 晶振和復位電路的設計 24
3.4 數(shù)碼管顯示電路設計 26
3.5 本章小結 28
第四章 系統(tǒng)軟件設計 29
4.1 系統(tǒng)總流程設計 29
4.1.1 通道選擇軟件設計 31
4.1.2 數(shù)據(jù)采集模塊軟件設計 32
4.2 數(shù)據(jù)采集與處理及數(shù)碼管顯示程序 33
第五章  總結 39
參考文獻 40
致 謝 42
附錄一 43
設計總電路圖 43
附錄二 44
設計總原理圖 44