【正文】 質(zhì)量下降。電網(wǎng)的損耗、電壓及功角穩(wěn)定性與無功功率快速、有效提供有關(guān)。關(guān)鍵詞：無功補(bǔ)償,單片機(jī),低電壓ABSTRACT What this article studies is based on the alteration of reactive power pensation of low voltage, then design an equipment for reactive power pensation of low voltage. As a kind of reactive power pensation, this equipment is basis on the electrical work monitor data ，and provides reactive power for city’s low voltage power grids. This thesis has discussed the importance of the reactive power pensation for the power grids ，and introduced the hardware and software of the controller. This device’s hardware core is AT89C52 SCM ，which has many merits such as high operating speed. This monolithic integrated circuit is the low voltage which American ATMEL Corporation produces, a high performance CMOS 8 monolithic integrated circuits；The software uses the assembly language to carry on the translation；The manmachine operation contact surface uses the LCD demonstration, the demonstration effect is quite good。作為一種非實(shí)時(shí)的無功補(bǔ)償裝置，該裝置以定時(shí)的電網(wǎng)監(jiān)測數(shù)據(jù)為依據(jù)，以低壓電網(wǎng)的無功補(bǔ)償為對象。本文主要研究了無功補(bǔ)償對電網(wǎng)性能的改善，以及控制器的軟硬件的配置。 A/D transformation uses ADC0809 ， it is a section of quite practical A/D switching device. This equipment may track the electrical work reactive power the change and the automatic pensation, and this installment has the volume to be small, the precision is high, the price pared to the higher merit.KEY WORDS: reactive power pensation，SCM(Single Chip Micyoco)，low voltage目 錄摘 要 ...............................................................................................................................IABSTRACT ..................................................................................................................II目 錄 ............................................................................................................................III第 1 章 前言 ..................................................................................................................11．1 無功補(bǔ)償裝置必要性 .................................................................................11．2 無功補(bǔ)償裝置的發(fā)展史 .............................................................................21．3 設(shè)計(jì)提要 .....................................................................................................4第 2 章 無功補(bǔ)償?shù)睦碚摲治?......................................................................................52．1 無功補(bǔ)償?shù)脑?.........................................................................................62．2 低壓電網(wǎng)中的幾種無功補(bǔ)償?shù)姆绞?.........................................................82．3 確定補(bǔ)償容量的幾種方法 .........................................................................92．3．1 從提高功率因數(shù)需要確定補(bǔ)償容量 ..........................................92．3．2 從降低線路有功損耗需要來確定補(bǔ)償容量 ..............................92．3．3 從提高運(yùn)行電壓需要來確定補(bǔ)償容量 ....................................10第 3 章 硬件設(shè)計(jì) ........................................................................................................123．1 無功補(bǔ)償裝置的技術(shù)要求 .......................................................................123．1．1 補(bǔ)償控制應(yīng)符合技術(shù)條件 ........................................................123．1．2 測量精度 ....................................................................................123．1．3 控制器原理 ................................................................................123．2 硬件介紹 ...................................................................................................133．2．1 微處理器 ....................................................................................133．2．2 A/D 轉(zhuǎn)換器選型 ......................................................................173．2．3 看門狗 ........................................................................................203．2．4 LCD 顯示 .................................................................................213．3 模擬信號調(diào)理電路 ...................................................................................233．3．1 電流電壓互感器 ........................................................................233．3．2 電壓、電流采樣及信號處理電路 ............................................243．4 輸出控制電路 ...........................................................................................253．4．1 控制電路 ....................................................................................253．4．2 固態(tài)繼電器 ................................................................................26第 4 章 軟件設(shè)計(jì) ......................................................................................................274．1 功率因數(shù)計(jì)算 ...........................................................................................274．2 投切原則 ...................................................................................................29第 5 章 結(jié)論與展望 ....................................................................................................31致謝 ..............................................................................................................................32參考文獻(xiàn) ......................................................................................................................33附錄 1：硬件結(jié)構(gòu)圖 ...................................................................................................34附圖 .....................................................................................................................34附錄 2：軟件程序 .......................................................................................................35第 1 章 前言1．1 無功補(bǔ)償裝置必要性目前，我國輸配電網(wǎng)無功缺乏，備用容量嚴(yán)重不足，無功補(bǔ)償裝置缺少靈活的調(diào)節(jié)能力，其中由于無功不足原因而產(chǎn)生電壓降落、電能傳輸損耗大、線路輸送容量降低和網(wǎng)絡(luò)穩(wěn)定性下降等問題表現(xiàn)尤為突出 [1]。我國互聯(lián)電網(wǎng)已經(jīng)進(jìn)入了大電網(wǎng)、大機(jī)組時(shí)代，大量的無功在網(wǎng)間傳送，造成了巨大的網(wǎng)絡(luò)損耗。對這些大沖擊非線性負(fù)荷或不對稱負(fù)荷應(yīng)進(jìn)行就地?zé)o功補(bǔ)償和用電污染治理，即對該類污染從源頭進(jìn)行治理，以達(dá)到電能質(zhì)量治理、節(jié)能降耗、增加產(chǎn)量和提高產(chǎn)品質(zhì)量的目的。無功功率對供電系統(tǒng)和負(fù)荷的運(yùn)行都是十分重要的 [2]。無功補(bǔ)償可以提高功率因數(shù)，是一項(xiàng)投資少，收效快的降損節(jié)能措施。同步補(bǔ)償器的實(shí)質(zhì)是同步電機(jī)，當(dāng)勵磁電流發(fā)生改變時(shí)，電動機(jī)可隨之平滑的改變輸出無功電流的大小和方向，對電力系統(tǒng)的穩(wěn)定運(yùn)行有好處。晶閘管的出現(xiàn)標(biāo)志著電力電子技術(shù)的誕生，并以此為起點(diǎn)，隨著半導(dǎo)體制造技術(shù)和變流技術(shù)的發(fā)展，新型的電力電子器件不斷問世，由此引發(fā)了眾多行業(yè)的變革，如交流變頻調(diào)速技術(shù)的蓬勃發(fā)展。現(xiàn)代并聯(lián)電容器補(bǔ)償裝置中的輸出回路就引進(jìn)了該項(xiàng)技術(shù)。(3)