【正文】 摘要 .............................................................................................................................................IABSTRACT ...............................................................................................................................II1 緒論 ..........................................................................................................................................1 功率因數(shù)研究意義 ........................................................................................................1 國內(nèi)外的研究現(xiàn)狀 ........................................................................................................1 本文的主要研究內(nèi)容 ....................................................................................................22 系統(tǒng)的工作原理 ......................................................................................................................3 異步電機的工作原理 ....................................................................................................3 旋轉(zhuǎn)磁場 .................................................................................................................3 旋轉(zhuǎn)磁場的轉(zhuǎn)向 ....................................................................................................5 影響功率因數(shù)的主要因素 ............................................................................................6 負載變化對電動機功率因數(shù)的影響 ....................................................................6 電壓變化對電動機功率因數(shù)的影響 ....................................................................6 功率因數(shù)測量原理 ........................................................................................................6 測量全阻抗法 ........................................................................................................7 直讀法 ....................................................................................................................7 相角差法 ................................................................................................................7 直流分量法 ............................................................................................................7 沖擊系數(shù)法 ............................................................................................................8 本文采用的測量方法 ...................................................................................................93 硬件電路設(shè)計 ........................................................................................................................11 系統(tǒng)的整體結(jié)構(gòu)圖 .....................................................................................................11 5V 直流電源電路 ................................................................................................12 12V 直流電源電路 ...........................................................................................15 變壓器的選擇 ......................................................................................................18 驅(qū)動電路設(shè)計 ..............................................................................................................20 晶閘管的觸發(fā)系統(tǒng) ..............................................................................................20 觸發(fā)脈沖的要求 ..................................................................................................21 驅(qū)動電路設(shè)計 ......................................................................................................22 控制部分電路設(shè)計 ......................................................................................................23 AT89C51 芯片簡介 .............................................................................................23 晶振電路 .............................................................................................................25 復(fù)位電路 .............................................................................................................28 電壓過零檢測電路 ..............................................................................................34 電壓和電流的信號提取電路 ..............................................................................34 顯示電路 ......................................................................................................................37 CD4511 七段譯碼器簡介： ...............................................................................37 LED 數(shù)碼管 .........................................................................................................394 軟件設(shè)計 ...............................................................................................................................42 編程軟件介紹 ..............................................................................................................42 程序主題設(shè)計思路 ......................................................................................................425 系統(tǒng)的抗干擾設(shè)計 ...............................................................................................................43 硬件抗干擾措施 ..........................................................................................................43 軟件抗干擾措施 ..........................................................................................................44結(jié)論 ...........................................................................................................................................46致謝 ...........................................................................................................................................47參考文獻 ...................................................................................................................................48附錄 .....................................................................4901 緒論 功率因數(shù)研究意義隨著我國經(jīng)濟的日益發(fā)展,電力需求不斷提高,伴隨而來的突出問題是能源無效的巨大消耗,資源利用率低下電力系統(tǒng)是一龐 大的系統(tǒng),其電能損耗的數(shù)值相當可觀,能源的合理配置是極需解決的問題。因此本設(shè)計通過分析研究功率因數(shù)與電機各項參數(shù)以及運行條件的關(guān)系，論證構(gòu)成電機的功率因數(shù)控制系統(tǒng)，達到節(jié)能目的。通常有兩大類 PFC 技術(shù)：一類是無源 PFC 技術(shù)；另一類是有源 PFC 技術(shù)。另外，第二級的設(shè)計也易于優(yōu)化，進一步提高性能。這種 PFC 技術(shù)在諸多文