外文翻譯--一種基于單片機(jī)的新型三相多費(fèi)率電能表的設(shè)計(jì)

1、<p><b>　　附件C：譯文</b></p><p>　　一種基于單片機(jī)的新型三相多費(fèi)率電能表的設(shè)計(jì)</p><p>　　Jishun Jiang Lanlan Yu</p><p>　　School of Electric and Electronic Enginee

2、ring School of Electric and Electronic Engineering</p><p>　　Shandong University of Technology Shandong University of Technology</p><p>　　Zibo, 255091, China

3、 Zibo, 255091, China</p><p>　　jandj8@sina.com yulanlan124@163.com</p><p><b>　　摘要：</b></p><p>　　隨著社會(huì)的發(fā)展，對(duì)電力的需求變得越來(lái)越大。在不同時(shí)間的電力不平衡現(xiàn)象日益嚴(yán)

4、重。為了合理調(diào)整電力負(fù)荷，節(jié)約能源，我們提出了一個(gè)新的多速率設(shè)計(jì)三相電度表。這種新型多速率三相電度表的設(shè)計(jì)原理是在AT89LV5基礎(chǔ)上提出的。硬件和軟件流程設(shè)計(jì)，以及實(shí)驗(yàn)數(shù)據(jù)的分析，詳細(xì)介紹。通過(guò)審判淄博億電子有限公司制造，它表明這種多速率三相電度表具有特色，是步行的精度，準(zhǔn)確測(cè)量，自動(dòng)抄表，靈活的時(shí)間設(shè)置，成本低。因此，這種新型三相多費(fèi)率電度表具有廣闊的應(yīng)用前景。</p><p>　　關(guān)鍵詞：多速率，三相電度表

5、，AT89LV52</p><p><b>　　一.引言</b></p><p>　　計(jì)算機(jī)技術(shù)的發(fā)展和應(yīng)用推動(dòng)了電表的智能化轉(zhuǎn)型。由于電力的需求增大，在不同時(shí)間的電力需求不平衡的現(xiàn)象越來(lái)越嚴(yán)重，電力公司鼓勵(lì)人們使用復(fù)費(fèi)率電度表[1]，以合理調(diào)整電力負(fù)荷，節(jié)省能源。傳統(tǒng)的復(fù)費(fèi)率電度表總是采用機(jī)械馬口鐵來(lái)衡量。也有一些不足之處，測(cè)量精度低與機(jī)械磨損快，單一的時(shí)間內(nèi)設(shè)置需

6、要強(qiáng)大的人力資源[2]。在本文中，我們?cè)贏T89LV52的基礎(chǔ)上提出一個(gè)新的多速率三相電度表。這種多速率三相電度表采用測(cè)量AD7752。它的特點(diǎn)是分時(shí)計(jì)量，計(jì)量準(zhǔn)確，液晶顯示直觀器，自動(dòng)抄表，靈活的時(shí)間設(shè)置，及時(shí)校正，成本低，設(shè)計(jì)新穎。</p><p><b>　　二.結(jié)構(gòu)和工作原理</b></p><p>　　本文提出的新穎的多速率三相電度表是基于AT89LV52單

7、片機(jī)[3]。 AT89LV52具有8K字節(jié)，三級(jí)加密程序存儲(chǔ)器，256字節(jié)的RAM，32個(gè)可編程I / O線(xiàn)，3次/ 16位和一個(gè)6向量2級(jí)停止計(jì)數(shù)器的RAM。該接口電路采用I2C總線(xiàn)的單位，是一個(gè)8位具有良好的性能和價(jià)格合適的單片機(jī)。該系統(tǒng)結(jié)構(gòu)圖見(jiàn)圖1。</p><p><b>　　圖1。系統(tǒng)結(jié)構(gòu)圖</b></p><p>　　這種多費(fèi)率電度表讀數(shù)的原則是多速率一次

8、使用RS485總線(xiàn)段并記錄在X25045然后接管RS485總線(xiàn)時(shí)鐘并將該時(shí)鐘寫(xiě)入CMOS芯片S3530A。三相交流電壓和電流通過(guò)電位儀和互感分別以生產(chǎn)小信號(hào)，傳送到AD7752完成測(cè)量。時(shí)鐘芯片S3530A提供了時(shí)鐘的自動(dòng)移動(dòng)過(guò)程中每秒的信息和分析這種時(shí)鐘屬于哪個(gè)時(shí)期根據(jù)預(yù)先設(shè)定的時(shí)間在X25045的時(shí)間然后保存在RAM存儲(chǔ)器電能按照相應(yīng)的時(shí)間期限。我們把它寫(xiě)的X25045的通訊地址，當(dāng)電能達(dá)到1度，以使多速率測(cè)量成真。這種電度表具有明

9、確的液晶顯示功能，缺相檢測(cè)，負(fù)荷控制，停止用電檢查和存儲(chǔ)，自動(dòng)抄表等</p><p>　　三．系統(tǒng)硬件電路的設(shè)計(jì)</p><p><b>　　A 電能計(jì)量</b></p><p>　　三相電能計(jì)量由ADI公司的低耗能CMOS芯片AD7752來(lái)實(shí)現(xiàn)了。在AD7752內(nèi)部，除了采用的ADC，濾波器和乘法電路，還有可以有效地消除噪聲的數(shù)字電路。采

10、樣過(guò)程中的電壓和電流的三相交流電源回路如圖2所示，其中IA代表A相電壓采樣。對(duì)B相和C相的取樣電路類(lèi)似A相。電源積分后轉(zhuǎn)化為電脈沖輸出。脈沖從CF口通過(guò)光電絕緣4N25進(jìn)入到空位的AT89LV52的INT0。 CPU測(cè)量電能[4]。我們通過(guò)S1和S2的聯(lián)系調(diào)節(jié)CF的脈沖數(shù)。電力能源和脈沖的轉(zhuǎn)換關(guān)系是W = MC的。其中，W是同千瓦時(shí)電能的單位，M是總脈沖數(shù)，C是電表脈沖數(shù)。我們選擇C=3000即每千瓦小時(shí)，，每千瓦時(shí) 3000脈沖。&l

11、t;/p><p>　　圖2。電度表的電路原理圖</p><p><b>　　B 液晶顯示器</b></p><p>　　該液晶顯示器[6]通過(guò)盛群公司的CMOS芯片對(duì)HT1621的實(shí)現(xiàn)12位數(shù)字顯示。HT1621是128段（32 × 4）內(nèi)部存儲(chǔ)器，LCD驅(qū)動(dòng)器。在HT1621內(nèi)部由控制電路和時(shí)間，內(nèi)存，液晶驅(qū)動(dòng)器和計(jì)時(shí)器。它有體積小

12、，成本低的優(yōu)點(diǎn)，使其使用于電度表。我們使用串行接口，在HT1621和AT89LV52之間只有4條線(xiàn)。詳細(xì)的連接如圖3所示。AT89LV52的P20,P21,P22,P23分別連接到CS,RD,WR并分別與數(shù)據(jù)使用翻新的RAM顯示。對(duì)HT1621驅(qū)動(dòng)器芯片已在48個(gè)節(jié)點(diǎn)的COM0，串口COM1，COM2端口，COM3連接到公共端和驅(qū)動(dòng)器的LCD和SG0，的SG1，SG2的，SG3連接到驅(qū)動(dòng)器輸出的每個(gè)部分分別輸出。此外，一個(gè)20kΩ的電阻

13、可調(diào)之間放置VDD和VLCD來(lái)調(diào)整液晶顯示對(duì)比度。實(shí)驗(yàn)表明，VDD= 5V比VLCD= 4V的更好。</p><p><b>　　C 串行存儲(chǔ)器</b></p><p>　　串行存儲(chǔ)器采用了XICOR公司的低功耗芯片X25045。它有三個(gè)功能看門(mén)狗定時(shí)器,電壓監(jiān)控和串行存儲(chǔ)器E2PROM的有512個(gè)字節(jié)?？撮T(mén)狗定時(shí)器可以設(shè)置的200ms，600ms和1400ms的時(shí)

14、間間隔。該軟件程序被讀入X25045。在正常運(yùn)行的程序，看門(mén)狗定時(shí)器收到的時(shí)間間隔，以確保程序的正常運(yùn)行觸發(fā)信號(hào)。如果看門(mén)狗定時(shí)器在時(shí)間間隔沒(méi)有收到觸發(fā)信號(hào)，X25045將輸出高級(jí)復(fù)位線(xiàn)。觸發(fā)電度表復(fù)位，以防止程序飛走。由于串行存儲(chǔ)器芯片，512 X25045的字節(jié)用于存儲(chǔ)的電能表的代碼，時(shí)間多速率時(shí)期，電力頂點(diǎn)，平滑用電，低谷電，上月和本月總電力。存儲(chǔ)可以分為兩個(gè)相同的地方。一個(gè)是作為數(shù)據(jù)存儲(chǔ)。另一種是用于備份。對(duì)存儲(chǔ)的數(shù)目可以修改1

15、0萬(wàn)次。數(shù)據(jù)可存儲(chǔ)100年。它是采用SPI總線(xiàn)連接AT89LV52。連接如圖3所示。</p><p>　　圖3。電度表的數(shù)字電路部分</p><p><b>　　D 時(shí)鐘電路</b></p><p>　　時(shí)鐘電路是由S3530A芯片完成。這是一個(gè)低功耗時(shí)鐘芯片，支持I2C總線(xiàn)。它通過(guò)CUP發(fā)送給RS485的數(shù)據(jù)來(lái)設(shè)置時(shí)鐘和日歷。同時(shí)，它繼續(xù)

16、走自己的振蕩時(shí)間。32.768 kHz的晶體振蕩器是把XIN和S3530A 的XOUT連接鎖定的CPU。 SDA的腳和SCL腳分別連接到AT89LV52的P1.6和P1.7。有兩個(gè)中斷的腳可作為第二分鐘輸出或輸出同步脈沖在一秒的時(shí)間內(nèi)供應(yīng)中斷信號(hào)給AT89LV52。單片機(jī)系統(tǒng)將讀出通過(guò)I2C通信接口當(dāng)前時(shí)間根據(jù)這一信號(hào)，并計(jì)算出這一段時(shí)間的電能，從而實(shí)現(xiàn)在不同時(shí)期的電能測(cè)量[5]。該時(shí)鐘電路用鋰電池。該電源VCC在正常供電線(xiàn)路是3.6V

17、的鋰電池電氣化供電。當(dāng)有電源關(guān)閉時(shí)，系統(tǒng)會(huì)自動(dòng)轉(zhuǎn)換成鋰電池供電的時(shí)鐘電路。時(shí)鐘仍在運(yùn)行準(zhǔn)確，即使關(guān)閉了電源。</p><p>　　E RS485通訊</p><p>　　MAX485芯片可實(shí)現(xiàn)RS485多費(fèi)率電能表通信控制。 MAX485芯片有RS485通訊協(xié)議。它可以在128 hypogenous電腦傳輸。它的傳輸距離大于1公里，其傳輸速率可達(dá)每秒250kb。該電度表連接通過(guò)RS48

18、5總線(xiàn)單元控制器。每個(gè)單元有一個(gè)單元控制器可以管理128多費(fèi)率電能表。該單元控制器連接到電腦的電源管理。每個(gè)電度表只有一個(gè)8位16進(jìn)制數(shù)米。電工應(yīng)寫(xiě)入用戶(hù)的信息和米數(shù)，然后導(dǎo)入到初次安裝電源管理的計(jì)算機(jī)，以便完成廣告的用戶(hù)和管理計(jì)算機(jī)的連接。管理計(jì)算機(jī)發(fā)送廣播通信地址信息并設(shè)定一段時(shí)間，沒(méi)有地址信息就沒(méi)有時(shí)鐘信息。電腦通過(guò)調(diào)用地址的方式更新資料。</p><p>　　F 缺相檢測(cè)和繼電器控制</p>

19、;<p>　　它可以實(shí)現(xiàn)繼電器控制[7] AT89LV52的P27。 P27可以控制繼電器使用4N25光電隔離器，以完成電源和功率控制。缺相檢測(cè)得到的信號(hào)是75K的電阻連接到1引腳的光電隔離器輸出的，分別通過(guò)二極管半波整流和濾波電容。我們發(fā)現(xiàn)了通過(guò)4引腳的隔離，以確定是否存在著缺相。如果有缺相，我們?cè)俅伟l(fā)現(xiàn)2秒后超時(shí)。我們打破立即關(guān)閉電源，如果有缺乏權(quán)力后，兩次確認(rèn)。在電源保護(hù)電路，它使用AT89LV52 INT1中斷腳檢

20、測(cè)信號(hào)。當(dāng)有一個(gè)突然斷電，INT1的跳躍進(jìn)入低電壓和INT1中斷進(jìn)入到電源保護(hù)方案，對(duì)儲(chǔ)能電容器依靠保存數(shù)據(jù)。在該系統(tǒng)中，AD7752的輸出脈沖，繼電器控制端口和缺相檢測(cè)的投入都用光電隔離器4N25。它發(fā)出的光耦合，可提高抗干擾能力電信號(hào)。</p><p><b>　　四.軟件設(shè)計(jì)</b></p><p><b>　　A 資源的分配</b>&

21、lt;/p><p>　　該軟件設(shè)計(jì)包括主程序，X25045的讀寫(xiě)程序，RS485串行通信程序，中斷服務(wù)程序，定時(shí)器處理程序，對(duì)HT1621顯示控制方案，在不同時(shí)間和不同功率的電能測(cè)量了保護(hù)方案，系統(tǒng)自檢與反干擾的處理方案。中斷系統(tǒng)資源的分布如下：INT0中斷的是AD7752脈沖測(cè)量，為檢測(cè)同步，計(jì)時(shí)器T0的INT1的使用時(shí)間為100毫秒，T1的為1ms的時(shí)間，并作為串行通信程序T2的波特率發(fā)生器。RS485的異步通信

22、設(shè)置為接收和發(fā)送中斷檢查信息。</p><p><b>　　B 模塊設(shè)計(jì)</b></p><p>　　主要程序流程圖如圖4所示。該電度表應(yīng)能在每個(gè)功率初始化時(shí)間。該計(jì)劃包括設(shè)置初始化工作模式定時(shí)器，串行氣孔和AT89LV52中斷，寫(xiě)入X25045的，S3530A和和對(duì)HT1621控制字。該系統(tǒng)設(shè)置三個(gè)時(shí)間段。該單片機(jī)每秒從S3530A讀取時(shí)鐘值，然后分析這些時(shí)鐘屬

23、于哪個(gè)時(shí)期，根據(jù)預(yù)先設(shè)定的時(shí)間在X25045的時(shí)間然后保存在RAM存儲(chǔ)器，電能按照相應(yīng)的時(shí)間期限。我們把它寫(xiě)入X25045的通訊地址，當(dāng)電能達(dá)到1度時(shí)。16位液晶顯示屏顯示的時(shí)間，并反過(guò)來(lái)顯示電能信息。</p><p><b>　　圖4。主程序流程圖</b></p><p><b>　　五.測(cè)試結(jié)果</b></p><p>

24、;　　測(cè)量誤差和運(yùn)行測(cè)試已在淄博億電子有限公司取得。epigenous計(jì)算機(jī)完成時(shí)間的管理和設(shè)置。這里有三種費(fèi)率的時(shí)間段。第一階段的時(shí)間是低峰期從00點(diǎn)00分鐘到06點(diǎn)30分鐘。時(shí)間的第二個(gè)時(shí)期是用電高峰期從06點(diǎn)30分鐘到22點(diǎn)30分鐘。第三階段的時(shí)間是正常用電時(shí)期從22點(diǎn)30分鐘到24點(diǎn)00分鐘。設(shè)置各個(gè)時(shí)間的用電效率并發(fā)送到計(jì)算機(jī)管理系統(tǒng)，電力公司根據(jù)國(guó)家政策調(diào)整并保存到X25045。用電高峰期，正常用電，用電低峰期，每月電力總讀

25、數(shù)保存在電能表，并通過(guò)單元控制器發(fā)送到epigenous計(jì)算機(jī)。通訊波特率是9600比特每秒。 0.1級(jí)標(biāo)準(zhǔn)的電子式電能表是標(biāo)準(zhǔn)的校驗(yàn)表并且是多費(fèi)率電能表的測(cè)試儀表。淄博億電子公司根據(jù)不同的負(fù)荷運(yùn)行已進(jìn)行了測(cè)試。在30kW的負(fù)荷下測(cè)量的數(shù)據(jù)見(jiàn)表1。</p><p>　　表一比較普通電能表和多費(fèi)率電能表</p><p>　　測(cè)試結(jié)果表明，該復(fù)費(fèi)率電度表誤差小于1％，屬于1.0級(jí)。反復(fù)讀數(shù)電能

26、精度和校正的時(shí)間是及時(shí)和正確的。通過(guò)測(cè)試，對(duì)降低用電計(jì)量誤差的方法可以得到。第一，調(diào)整AD7752采樣電阻的準(zhǔn)確值。其次，需要這個(gè)電阻值隨溫度變化的較少。第三，在電力計(jì)量的過(guò)程中，當(dāng)電力尾數(shù)部分不足0.01，其余的脈沖應(yīng)該在一起訪問(wèn)，從而累積誤差不足0.01度，能量損失是可以避免的。</p><p><b>　　六.結(jié)論和展望</b></p><p>　　多費(fèi)率電能表

27、在不同的時(shí)間根據(jù)不同的設(shè)置完成電能計(jì)算。它采用485串行通信，實(shí)現(xiàn)自動(dòng)抄表和實(shí)時(shí)校正。淄博億電子公司生產(chǎn)的結(jié)果表明，在本文的多速率三相電度表有新穎的設(shè)計(jì)技術(shù)，精確測(cè)量的特點(diǎn)，靈活的時(shí)間設(shè)置。各項(xiàng)技術(shù)指標(biāo)達(dá)到國(guó)家智能卡電能表的技術(shù)標(biāo)準(zhǔn)。因此，它具有廣泛的應(yīng)用前景。</p><p><b>　　譯文原文出處：</b></p><p>　　Jishun Jiang ; La

28、nlan Yu ; Sch. of Electr. & Electron. Eng., Shandong Univ. of Technol., Zibo, China . Design of a New Three-Phase Multi-Rate Watt-Hour Meter Based on Singlechip . Computational Intelligence and Software Engineering,

29、2009. CiSE 2009. International Conference on .</p><p><b>　　參考文獻(xiàn)：</b></p><p>　　[1] Bu Zhengliang, Yin Xianggen, Tu Guangyu. “Development of HV Watt-hour meter.” Automation of Electric

30、 Power Systems, 2006, 30(19): 89-93.</p><p>　　[2] Kosukegawa M., Sakumoto Y. “Traceability system of electric energy standard and tendency in static watthour meter development in Japan.” Sixth International

31、Conference on Metering Apparatus and Tariffs for Electricity Supply, 1990,4: 259-263.</p><p>　　[3] Xuehai Li. Applied tutorial of singlechip. Electronic industry publishing company, 2003.</p><p>

32、;　　[4] Al-Khateeb Tarik, Blundel Martin. “An electronic meter for measuring the saving in electrical power.” The Ninth Arab International Conference on Solar Energy (AICSE-9), Kingdom of Bahrain, 2007,4 (209):328-333.<

33、;/p><p>　　[5] Liu Ying, Liu Qingyu. “Development of a self-calibration precision electrical measuring meter.” Proceedings of the 1998 Conference Precision Electromagnetic Measurements, 1998,7:276.</p>&l

34、t;p>　　[6] Gao Yun-Peng, Teng Zhao-Sheng, Liu Peng. “Design of three-phase multi-functional harmonic energy meter.” Journal of Hunan University Natural Sciences, 2008, 35(9): 53-57.</p><p>　　[7] Qu Qingcha

35、ng. “Key technology to three-phase electric meter and high voltage electric power measurement.” Acta Metrologica Sinica, 2007, vol28: 25-30.</p><p><b>　　英文原文：</b></p><p>　　Design of

36、a New Three-phase Multi-rate Watt-hour Meter Based on singlechip</p><p>　　Jishun Jiang</p><p>　　School of Electric and Electronic Engineering</p><p>　　Shandong University of Technol

37、ogy</p><p>　　Zibo, 255091, China</p><p>　　jandj8@sina.com</p><p><b>　　Lanlan Yu</b></p><p>　　School of Electric and Electronic Engineering</p><p&

38、gt;　　Shandong University of Technology</p><p>　　Zibo, 255091, China</p><p>　　yulanlan124@163.com</p><p><b>　　Abstract</b></p><p>　　With the development of t

39、he society, the demand of electric power becomes bigger and bigger. The phenomenon of unbalanced electricity in different time is worse and worse. In order to adjust electric power burthen with reason and save energy, we

40、 put forward the design of a novel multi-rate three-phase watt-hour meter. The design principle of a novel multi-rate three-phase watt-hour meter based on AT89LV5 is proposed in this paper. The designs of hardware and so

41、ftware flow, as well as the analysi</p><p>　　Keywords-multi-rate, three-phase watt-hour meter,AT89LV52</p><p>　　INTRODUCTION</p><p>　　The development and application of computer tec

42、hnology push the construction of intellectualized section exteriorly. Because the phenomena of bigger demand of electric power and unbalanced electricity in different time is worse and worse, electric power company has e

43、ncouraged people to use multi-rate watt-hour meter [1] in order to adjust electric power burthen with reason and save energy. The traditional multi-rate watt-hour meter always adopts mechanical tinplate to measure. There

44、 are some sho</p><p>　　STRUCTURE AND WORKING PRINCIPLE</p><p>　　The novel multi-rate three-phase watt-hour meter proposed in this paper is based upon AT89LV52 singlechip [3]. AT89LV52 has the fl

45、ash memorizer with 8k bytes, cryptographical program memorizer with third class, RAM with 256 bytes, 32 programmable I/O lines, three time/ counter with 16 bits and a two class halt with six vectors. The interface circui

46、t adopts I2C bus unit which is a 8 bits singlechip with good performance and suitable price. The system structure diagram is shown in figure 1.</p><p>　　Figure 1. System structure diagram</p><p>

47、;　　The principle of this multi-rate watt-hour meter is reading in the multi-rate time segments using RS485 bus and noting in X25045 then take over correctional clock with RS485 bus and write in clock CMOS chip S3530A. Th

48、e three-phase AC voltage and electric current pass through potentiometer and mutual inductance instrument respectively so as to produce small signal which is sent to AD7752 to complete measurement. The clock CMOS chip S3

49、530A gives clock information per second in the course of automa</p><p>　　according to corresponding period of time. We write it to corresponding address of X25045 when the electrical energy achieves one degr

50、ee in order to make the multi-rate measurement come true. This watt-hour meter has functions of clear LCD display, missing phase detection, burthen control, halt electricity check and storage, automatic meter reading and

51、 so on.</p><p>　　THE DESIGH OF HARDWARE CIRCUIT</p><p>　　A． Electrical energy measurement</p><p>　　The three-phase electrical energy measurement is realized by the low consume CMOS

52、chip AD7752 of ADI company. The inside of AD7752 adopts digital circuit besides ADC, filter and multiplication circuit which can eliminate noises effectively. The sampling course of voltage and electric current in three-

53、phase AC power supply loop is shown in figure 2 in which IA stands for voltage sampling of A phase. The sampling circuits of B phase and C phase are similar to A phase. The power after integral is t</p><p>　

54、　Figure 2. Circuit schematic diagramof watt-hour meter</p><p>　　B． LCD display</p><p>　　The LCD display [6] adopts HT1621 CMOS chip of HOLTEK Company to achieve twelve bits digital display. HT16

55、21 is the LCD drivers with 128 segments (32× 4) inner memorizer. The interior of HT1621 consists of control and time circuits, RAM, LCD drive and watch timer. It has</p><p>　　the merits of small volume

56、and low cost so that it is suit to watt-hour meter. We use serial interface which only has four lines between HT1621 and AT89LV52. The detailed connection is shown in figure 3. P20, P21, P22 and P23 of AT89LV52 connect t

57、o CS, RD, WR and DATA respectively with the use to refurbish the display of RAM. HT1621 drive CMOS chip has 48 nodes in which COM0, COM1, COM2, COM3 connect to the communal end and drive output of LCD and SG0, SG1, SG2,

58、SG3 connect to drive output of ev</p><p>　　C． Serial memorizer</p><p>　　Serial memorizer adopts low power consumption chip X25045 of XICOR company .It has three functions which are watchdog time

59、r WTD, voltage supervision and serial memorizer E2PROM with 512 bytes. WTD can be set 200ms, 600ms and 1400ms time intervals. The software program is read into X25045. During the normal running of program, WTD receives t

60、he trigger signal in time intervals in order to ensure the normal running of program. X25045 will output a high potential through RESET line if WTD does not r</p><p>　　D． Clock circuit</p><p>　　

61、The clock circuit is completed by S3530A chip. It is a low power consumption clock chip that supports I2C Bus. It sets the clock and calendar according to the data received by CUP communicating with RS485. At the same ti

62、me, it continues to walk time by its own oscillation. The crystal oscillator of 32.768 kHz is put between Xin and Xout of S3530A which is connected with CPU through latching. SDA foot and SCL foot connect to P1.6 and P1.

63、7 of AT89LV52 respectively. There are two interrupt alarming</p><p>　　Figure 3. Partial circuit figure of watt-hour meter</p><p>　　E． RS485 Communication </p><p>　　MAX485 chip can i

64、mplement RS485 communication control of multi-rate watt-hour meter. MAX485 chip has RS485 communication protocol. It can take 128 hypogenous computers. Its transmission distance is greater than 1km and its transfer rate

65、is up to 250kb per second. The watt-hour meter connects with the unit controller through the RS485 bus. Each unit has a cell controller can manage 128 multi-rate watt-hour meter. The cell controller connects to power man

66、agement computer. Each watt-hour meter has </p><p>　　F． Lack Phase detection and relay control</p><p>　　It can achieve relay control [7] with P27 of AT89LV52. P27 can control relays using 4N25 p

67、hotoelectricity isolator so as to complete power supply and power control. Lack Phase detection gets the signal from fan-out of the relay and connects to 1 foot of photoelectricity isolator after passing a 75K resistance

68、, the diode half-wave rectifier and capacitive filtering respectively. We detect the 4 foot of isolator to determine whether there is the lack of phase. If there is lack of phase, we detect </p><p>　　When th

69、ere is a sudden power off, INT1 jumps into a low voltage and the INT1 interrupt enters to the power protection program relying on the energy storage capacitor to save data. In the system, pulse output of AD7752, relay co

70、ntrol port and the inputs of lack phase detection all use photoelectric isolator 4N25. It sends electrical signal by light coupling which can enhance the ability of anti-jamming.</p><p>　　THE DESIGN OF SOFTW

71、ARE</p><p>　　A．The distribution of resource</p><p>　　The software program includes main program, X25045 read and write program, RS485 serial communication program, interrupt serve program, timer

72、 handling program, HT1621 display control program, electrical energy measurement in different period of time and power down protection program, and system self-checking and anti-interference handling program. Interrupt r

73、esource distribution of system is: INT0 interrupt is used as AD7752 pulse measurement, INT1 as synchronization detecting, timer T0 as 100 m</p><p>　　interrupt and check information for sending.</p>&l

74、t;p>　　B． Module desigh</p><p>　　The flow chart of main program is shown in figure 4. The watt-hour meter should be able to initialize at each power up time. The initializing program includes setting worki

75、ng mode of timers, serial stomata and interrupts for AT89LV52, writing control word into X25045, S3530A and</p><p>　　HT1621. This system sets three periods of time. The singlechip reads clock value from S353

76、0A per second then analyze this clock belongs to which period of time according to advance periods of time set in X25045 then save the electrical energy in RAM memorizer according to corresponding period of time. We writ

77、e it to corresponding address of X25045 when the electrical energy achieves one degree. The LCD display with 16 bits shows period of time and electrical energy information in turn. </p><p>　　Figure 4

78、. Flow chart of main program</p><p>　　TESTING RESULT</p><p>　　Error measurement and running test have been made in Zibo Billion Electron Co., Ltd. The epigenous computer completes the setting of

79、 time management. There are three-rate period of time. The first period of time is vale electricity from 00 point 00 minute to 06 point 30 minutes. The second period of time is apex electricity from 06 point 30 minutes t

80、o 22 point 30 minutes. The third period of time is smooth electricity from 22 point 30 minutes to 24 point 00 minute. The setting of rate period of </p><p>　　TABLE I. COMPARE OF NORMAL METER AND TESTING METE

81、R</p><p>　　The testing result indicates that the error of this multi-rate watt-hour meter is less than 1%, belongs to 1.0 grade. The return reading of electrical energy is precision and the emendation of tim

82、e is timely and right. By testing, the method of decreasing errors for electricity metering can be obtained. Firstly, adjust the sampling resistance of AD7752 to accurate value. Secondly, the value of this resistance is

83、needed less varying with temperature. Thirdly, during electricity metering progress,</p><p>　　VI. CONCLUSION AND EXPECTATION</p><p>　　The multi-rate watt-hour meter achieves electrical energ

84、y computation in different time according to different time setting. It adopts RS485 for serial communication and realizes automatic meter reading and real-time emendation. The results of production in Billion Electron C

85、ompany show</p><p>　　that the multi-rate three-phase watt-hour meter proposed in this paper has the characteristics of novel design technique, accurate measurement, and flexible time period setting. Various

86、technical indexes achieve the technique standard for national intelligent card watt-hour meter. Therefore, it has wide application.</p><p>　　REFERENCES</p><p>　　[1] Bu Zhengliang, Yin Xianggen,

87、Tu Guangyu. “Development of HV Watt-hour meter.” Automation of Electric Power Systems, 2006, 30(19): 89-93.</p><p>　　[2] Kosukegawa M., Sakumoto Y. “Traceability system of electric energy standard and tenden

88、cy in static watthour meter development in Japan.” Sixth International Conference on Metering Apparatus and Tariffs for Electricity Supply, 1990,4: 259-263.</p><p>　　[3] Xuehai Li. Applied tutorial of single

89、chip. Electronic industry publishing company, 2003.</p><p>　　[4] Al-Khateeb Tarik, Blundel Martin. “An electronic meter for measuring the saving in electrical power.” The Ninth Arab International Conference

90、on Solar Energy (AICSE-9), Kingdom of Bahrain, 2007,4 (209):328-333.</p><p>　　[5] Liu Ying, Liu Qingyu. “Development of a self-calibration precision electrical measuring meter.” Proceedings of the 1998 Confe

91、rence Precision Electromagnetic Measurements, 1998,7:276.</p><p>　　[6] Gao Yun-Peng, Teng Zhao-Sheng, Liu Peng. “Design of three-phase multi-functional harmonic energy meter.” Journal of Hunan University Nat

92、ural Sciences, 2008, 35(9): 53-57.</p><p>　　[7] Qu Qingchang. “Key technology to three-phase electric meter and high voltage electric power measurement.” Acta Metrologica Sinica, 2007, vol28: 25-30.</p>