2012年重庆理工大学---计控设计---简易交流采样

目录摘要······································································································3Abstract································································································4概述······································································································51.1设计的意义···············································································51.2设计的主要功能·········································································5系统总体方案设计···················································································62.1交流采样原理············································································62.2原理框图及各功能单元之间的逻辑关系···········································72.3设计任务的分析·········································································72.4单片机最小系统·········································································72.5具体模块··················································································7硬件电路具体设计···················································································93.1AT89C52主控制器模块··································································93.1.1AT89C52管脚图·····································································93.1.2管脚说明·············································································93.2ADC0809模数转换模块································································103.2.1ADC0809管脚图···································································103.2.2引脚功能说明·····································································103.374LS245译码模块······································································113.4显示模块··················································································11系统的软件设计····················································································124.1应用软件简介··········································································124.1.1keil简介···········································································124.1.2protues简介······································································134.2设计相关流程··········································································134.1.1程序流程图········································································134.1.2D/A转换子程序流程流程图····················································14系统仿真······························································································15元件清单······························································································16结束语·································································································17参考文献······························································································18附录：源程序························································································19重庆理工大学计算机控制技术综合应用设计论文2摘要随着电力系统的快速发展,电网容量的扩大使其结构更加复杂,实时监控、调整的自动化显得尤为重要。而在电力调度自动化系统中,电力参数的测量是最基本的功能。如何快速、准确地采集各种电力参数显得更加重要。在实现自动化的过程中,最关键的环节是数据采集。根据采集信号的不同,可分为直流采样和交流采样两种。交流采样是按一定规律对被测信号的瞬时值进行采样，再按一定算法进行数值处理，从而获得被测量的测量方法。由于这种方法能够对被测量的瞬时值进行采样,因而实时性好,相位失真小。目前，单片机、DSP及A/D转换器的大量涌现，为交流采样技术提供了强有力的硬件支持。本次设计采用单片机AT89C52现电力调度自动化系统中的简易交流采样,即系统采集的是交流电压和电流，不需变送器进行交直流转换。模数转换器ADC0809对三相交流电压分时进行模数转换，把得到的数字量送入单片机进行数据处理，然后通过LED数码管显示电压的实时值。关键词：数据采集，交流采样，A/D转换器，单片机AT89C52，模数转换重庆理工大学计算机控制技术综合应用设计论文3AbstractWiththefastdevelopmentofpowersystem,powergridcapacityisexpandedsothatitsstructureismorecomplex,realtimemonitoring,adjustingtheautomationisveryimportant.Intheautomationofpowersystemdispatching,powerparametersmeasurementisthemostbasicfunction.Howfast,accurateacquisitionofvariouselectricpowerparameterismoreimportant.Intherealizationoftheautomationofprocess,isthekeylinkindataacquisition.Accordingtothecollectedsignals,canbedividedintoDCsamplingandACsamplingtwo.ACsamplingisregularlymeasuredsignalinstantaneousvaluesampling,andaccordingtoacertainalgorithmfornumericalprocessing,thusobtainedwasthemeasuremethod.Becausethismethodcanmeasuretheinstantaneousvalueofthesample,andgoodreal-timeperformance,phasedistortionissmall.Atpresent,MCU,DSPandA/Dconverterinlargenumbers,forACsamplingtechnologyprovidesapowerfulhardwaresupport.ThisdesignusesasinglechipAT89C52modernelectricpowerdispatchingautomationsysteminsimpleACsampling,namelythesystemacquisitionisACvoltageandcurrent,withouttransmitterforAC/DCconversion.AnalogtodigitalconverterADC0809onthree-phaseACvoltagedividedbytheconversion,thedigitalquantityintothesingle-chipmicrocomputerfordataprocessing,andthenthroughtheLEDdigitaldisplayvoltagerealtimevalue.Keywords:Dataacquisition，ACsampling，A/Dconverter，single-chipAT89C52，analog-to-digitalconversion重庆理工大学计算机控制技术综合应用设计论文4概述1.1设计的意义近年来，随着通信技术和计算机技术的发展，通信电源监控系统开始进入实用阶段。监控系统的主要功能是对设备进行监测、控制，而数据采集又是实现这一功能的最重要和最基本的环节，尤其是如何准确快速地采集各个模拟量，一直是人们所关注的问题。根据采样信号的不同，采样方法可分为直流采样和交流采样。直流采样是采集经过变送器整流后的直流量，然后由Ａ/Ｄ转换器送入主机，此方法软件设计简单、计算方便，对采样值只需作一次比例变换，即可得到被测量的数值，具有采样周期短的优点。因此，在监控系统发展初期，这一方法得到了广泛的应用。但直流采样方法存在着以下一些不足：（1）具有较大的时间延迟，难以及时反应被测量的突变，为了提高响应速度，变送器的时间常数必须特殊设计，因而不宜普遍使用；（2