基于ADE7878的智能三相电度表的设计

学号_2008302540101__密级________________武汉大学本科毕业论文基于ADE7878的智能三相电度表的设计院（系）名称：电气工程学院专业名称：电气工程与自动化学生姓名：黄鹤鸣指导教师：蒋云峰副教授二○一二年六月武汉大学本科生毕业论文基于ADE7878的智能三相电度表的设计College：电气工程学院Subject：电气工程与自动化Name：黄鹤鸣Director：蒋云峰Professor二○一二年六月BACHELOR'SDEGREETHESISOFWUHANUNIVERSITYThedesignofsmartthree-phaseelectricitymeterbasedonADE7878College：ElectricalEngineeringCollegeSubject：ElectricalEngineeringandautomationName：HemingHuangDirector：YunfengJiangProfessorJune2012郑重申明本人呈交的学位论文，是在导师的指导下，独立进行研究工作所取得的成果，所有数据、图片资料真实可靠。尽我所知，除文中已经注明引用的内容外，本学位论文的研究成果不包含他人享有著作权的内容。对本论文所涉及的研究工作做出贡献的其他个人和集体，均已在文中以明确的方式标明。本学位论文的知识产权归属于培养单位。本人签名：日期：I摘要随着电网的大规模的改造与建设，电力系统对三相智能电度表的需求不断增长，提出了高精度、多参数测量、谐波功率电能计量，实时测量等技术要求。本文以智能三相电表为研究对象，采用电能计量芯片ADE7878和单片机AT89S52设计三相电度表，介绍了计量电路原理、系统结构特点及硬件电路设计。针对配电网正常负荷情况下的精确计量，提出了分时段计量的远程通信电度表设计方案。本文中智能三相电度表实现的基本思路概述为:1、通过CT与PT，实现七路模拟信号输入计量芯片ADE7878；2、ADE7878通过模数转换、数字信号处理、电能计量、数频转换，实现电量的SPI输出和脉冲输出；3、单片机AT89S52通过对瞬时有功功率的检测，实现了功率的精确计量；通过对时间参数的检测，实现了定时存储和分时计量。本文包括以下三个方面的具体设计：1、实现三相电参量的测量，即电压和电流信号的精确采集；2、系统结构框图的设计；3、系统硬件电路设计，具体包括计量电路的设计，计量芯片ADE7878与单片机AT89S52的接口电路设计，单片机外围电路设计以及显示模块、数据存储、时钟芯片和电源模块的设计。本次设计重点完成了智能三相电度表硬件部分的理论设计和软件部分程序流程图设计。鉴于能力和实验环境的局限，未分别进行各个模块的软件设计、样表的设计及仿真调试。但提出了一种高精度的配电网电力负荷计量电表的设计方案，具有一定的参考性。关键词：ADE7878，AT89S52，精确计量，分时段计量IIABSTRACTWiththelarge-scaleupgradingandconstructionofthepowergrid,powersystemasksforagrowingdemandofthethree-phasesmartenergymeter,andputsforwardahigh-precision,multi-parametermeasurement,harmonicpowerenergymetering,real-timemeasurementoftechnicalrequirements.Theintelligentthree-phaseenergymeterisstudiedanddiscussedinthispaper．WithADE7878aselectricalenergymeasurementICandAT89S52ascontrolunit，theprincipiumofmeasuringcircuit,thedesignofhardwarecircuit,andcharactersofsystemstructureareintroduced．Astoachievingaccuratemeteringundernormalloadforpowersystem，thisPaperpresentsanewstrategyofthree-phaseenergymeterwiththefunctionofsub-periodmeteringandremotecommunication.Inthisarticle,thebasicideawhichsmartthree-phasewatt-hourmeteristoachieveissummarizedasfollows:1、WiththeuseofCTandPT,sevenchannelsofanalogsignalsinputthemeasurementchipADE7878；2、Withtheuseofanalog-to-digitalconversion,digitalsignalprocessing,energymeasurement,anddigital-to-frequencyconversion,themeasurementchipADE7878achieveselectricitySPIoutputandpulseoutput；3、MCUAT89S52achievesaccuratemeteringofpowerbythedetectionoftheinstantaneousactivepower,andcompliestimingstorageandinstantaneousmeasurementbythedetectionoftimeparameter.Thisarticleincludesthefollowingthreeaspectsofthespecificdesign：1、achievingthemeasurementofthethree-phasepowerparameters,whichincludetheaccurateacquisitionofvoltageandcurrentsignals；2、thedesignofthesystemblockdiagram；3、thesystemhardwarecircuitdesign,specificallyincludingthedesignofthemeteringcircuit,theinterfacecircuitbetweenthemeasurementchipADE7878andtheMCUAT89S52,MCUperipheralcircuitdesign,andthedesignofthedisplaymodule,datastorage,theclockchipandpowersupplymodules.Thisdesigncompletedthetheoreticaldesignofthehardwarepartofthesmartwatt-hourmeter.Giventhecapabilitiesandlimitationsoftheexperimentalenvironment,wehaven'tdonethedesignofsoftwarepart,thesamplemeterandsimulationdebugging.However,weproposedakindofdistributiongridelectricityloadmeasurementprogramforthedesignofenergy-meteringmeter,whichhashighaccuracyandsomekindofreferringvalue.Keywords：ADE7878，AT89S52，accuratemetering，sub-periodmeteringIII目录第1章绪论..............................................................................................................11.1概述..................................................................................................................11.2智能电度表技术现状与发展趋势..................................................................21.3本文设计方案的特点和相应需要解决的问题..............................................31.4电度表参数配置..............................................................................................31.5论文组织结构..................................................................................................4第2章电能计算的理论基础.............................................................................52.1电压、电流有效值及谐波参数的计算..........................................................52.2功率与电能的计算..........................................................................................72.4频率的计算......................................................................................................9第3章系统结构框图与设计要求..................................................................103.1结构框图........................................................................................................103.2电表显示内容及其设计要求........................................................................11第4章系统硬件电路设计与实现..................................................................124.1计量芯片ADE7878......................................................................................124.1.1ADE7878引脚配置及功能描述......................................................124.1.2计量电路原理......................................................................................174.2单片机外围电路设计与器件选择..............