工频电场测量方法及安全警示系统设计研究

工频电场测量方法及安全警示系统设计研究⑧重庆大学硕士学位论文(学术学位)学生姓名：刘聪汉指导教师：何为教授专业：电气工程学科门类：工学重庆大学电气工程学院二0一二年五月ResearchonMeasurementMethodandSafetyWarningSystemDesignofPowerFrequencyElectr．icField⑧AThesisSubmittedtoChongqingUniversityinPartialFulfillmentoftheRequirementfortheMaster’SDegreeofEngineeringBy_LiuConghanSupervisedbyProf．HeWeiSpecialty：ElectricalEngineeringCollegeofElectricalEngineeringofChongqingUniversity，Chongqing，ChinaMay,2012重庆大学硕士学位论文一主茎塑墨—_—__—I●—_-——__—_-_—●——--——●—-●——l_—●-—__—__——_——-_——-——_——-————————————一一摘要电场是表征输电线路及电力设备状态的一个重要电气参量，通过一定的理论研究和实测验证，电场测量技术可作为输电线路故障状态诊断及带电作业安全距离确定的辅助分析工具。实时准确的测量电场，可为输电线路状态诊断、电力设备绝缘状态评估、电力系统电磁兼容及电磁环境测评等领域研究提供有力的数据支持，在探讨电场对作业人员健康的长期影响、保障高强度电场环境下人身安全、研究高压输电线路非接触式测量及保证电力系统安全稳定运行等方面起着至关重要的作用。推导球型传感器测量一维交变电场的数学原理，讨论引入传感器对电场造成的畸变，并提出减小其造成测量误差的解决方案；建立合理的高压输电线路下工频电场计算模型，对线路缺相及相位异常时电场分布情况做了仿真并得到了相应参考数据，提出根据输电线路故障前后工频电场不同分布规律判断输电线路状态的理论方法；介绍带电作业中确定安全距离重要性，分析电场强度表征带电作业安全距离的可行性，讨论现有确定安全距离的理论和技术方法，针对现有技术方法的缺陷提出基于电场过限确定安全距离的思路，通过仿真计算得到不同电压等级输电线路安全距离的临界电场。分析平行板电容传感器测量电场的可行性并完成传感器的设计，采用平板电容传感器代替球型传感器实现测量；根据系统各个模块的具体需要，选择合适器件完成系统的硬件设计，根据测量需要完成系统的软件调试，最终完成基于C8051F410单片机的便携式高压工频电场测量与警示仪的整体设计；对传感器进行工频电场校正实验，用自制的仪器与国外电磁场测量仪进行对比测量，对系统进行校准；分析人体存在对测量电场的影响，在数据处理引入增强因子对人体造成的测量误差进行了校正。测试结果表明，平行板电容传感器可用于工频电场测量，在工频电场作用下的刻度因数为18kV．聊-。．mV～，设计的电场测量系统能够对输电线附近的工频电场进行准确测量及实现电场过限报警的功能，测量相对误差在10％左右。系统整体测量性能良好，与国外仪器的测量结果对比相关度很高，可满足工程测量需要。关键词：电场传感器，工频电场测量，故障判断，安全距离AbstractTheelectricfieldisanimportantelectricalparametercharacterizingstatusoftransmissionlinesandpowerdevices，bysometheoreticalstudiesandexperimentalveriftcation．theelectricfieldmeasurementtechniquecanbeusedasanauxiliaryanalysistoolfortransmissionlinefaultconditiondiagnosisanddeterminingsafedistanceinliveworking．Itwillprovidestrongdatasupporttotransmissionlinesstatediagnosis，electricalequipmentinsulationconditionassessment，powersystemelectromagneticcompatibility，electromagneticenvironmentassessmentandotherstudiesbyreal．timeandaccuratelymeasuringelectricfield．Ithasgreatsignificanceforinvestigatingelectricfieldeffectstothelong—termhealthofworkers，protectingpersonalsafetyofpeopleinhigh—strengthelectricfieldenvironment，studyingonnon．contactmeasurement，ensuringthesafeandstableoperationofpowersystems，andSOOn．Itisdeducedthemathematicalprincipleofmeasuringone—dimensionalaltematingelectricfieldusingsphericalsensor．TheelectricfielddistortionwhensensoriSintroductiontothefieldisdiscussed，andasolutionforreducingmeasurementerrorcausedbysensorisproposed；arationalcalculationmodelofpowerfrequencyelectricfieldunderhighvoltagetransmissionlineisestablished，distributionofelectricfieldwhenlineisphaselossandabnormalissimulated，andtheccorrespondingreferencedataisgot．Theoreticalmethodforestimatingthestateofthetransmissionlinebasedonelectricfielddistributionlawbeforeandafterthetransmissionlinefaultisproposed；Itisintroducedtheimportanceofdeterminingsafedistanceandanalyzedthefeasibilityoftheelectricfieldcharacterizingsafedistancewhenliveworking，thedefectsofexistingtheoreticalandtechniquemethodsfordeterminingsafetydistanceisdiscussed，andanewideafordeterminingsafedistancebasedonelectricfieldoverlimitisproposed，thecriticalelectricfieldsfortransmissionlineswithdifferentvoltagelevelsinsafedistanceiscalculatedbysimulation．Itisanalyzedandverifiedthefeasibilityofmeasuringtheelectricfieldflatplatecapacitancesensorandcompletedsensordesign．Theflatcapacitancesensorisusedtomeasureelectricfieldinsteadofballsensor．Accordingtothespecificneedsofeachmodule，hardwaredesignofthesystemiscompletedbyselectingappropriatecomponents，andsoftwaredebuggingofthesystemiscompletedaccordingtoIImeasurememsneed，theoveralldesignoftheportablehigh。voltagepowerfrequencyelectricfieldmeasurementandcautionapparatuswithC8051F410MCUasthecoreisfinished：Sensoriscalibratedinpowerfrequencyelectricfield，Thecomparisonmeasurementandcalibrationexperimentbetweenhomemadeinstrumentandforeignelectromagneticfieldmeasurementinstrumentisproceeded；theeffectonmeasuringelectricfieldwithhumanexistenceisanalyzed，andtheenhancedfactorsisintroducedtocorrectingformeasurementerrorcausedbythehumanbodyduringdataprocessing．ThetestresultsshowthatthefiatplateelectricfieldsensorscanusetomeasureDowerfrequencyelectricfield，thescalefactorunderpowerfrequencyelectricfieldis18七y．m～．mV～，andthemeasurementsystemisabletomeasurepowerfrequencyelectricfieldaroundpowerlinesaccuratelyandfinishthewarningfunctionwhenelectricfieldisoverlimit，measurementdatarelativeerrorsareabout10％．Thewholesystemhasgoodmeasurementperformance．Themeasurementresultshavehighcorrelationcomparedwiththeforeigninstrument，SOitcanmeettheneedsofengineeringmeasurement．Keywords：electricfieldsensor，powerfrequencyelectricfieldmeasuremem，faultdiagnosis，safedistanceIII重庆大学硕士学位论文目录目录中文摘要⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯I英文摘要⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯．．II1绪论⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11．1课题背景和意义⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11．1．1测量电力设备工频电场⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11．1．2测量瞬态电场⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯21．1．3工频电磁环境测评⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯21．1．4工频电场测量的意义⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯31．2工频电磁场环境及人体暴露限值标准⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯31．2