PQ测量仪器与技术基础(1)

3-PhasePowerSystems三相电力系统,Electricityisgeneratedbyconductorsrotatingthoughamagneticfield电是由在磁场中旋转的导体产生的,Pickapointonacircle,rotatingcounterclockwiseatafixedspeed.Whentheangleissmallthechangeinheightisrapid.Astheangleincreasestowards90thechangeinheightslows.Thedistancefromthe“thehorizon”sweepsoutasinewave.在圆周上选一个点，该点以固定速率在圆周上向逆时针方向旋转。当旋转的角度比较小时，高度的变化就比较明显；当旋转角度向90方向增长时，高度的变化也组件减缓。偏离“水平”方向的高度即形成了一个正弦波。,WhySineWaves?为什么会是正弦波？,Why3-Phase?为什么为三相？,Atanyinstantthenetcurrentontheneutraliszero.Tryit!在任何情况下，零线上的净电流为零。试试看！Threephasemotorshavebetterstartingtorque,runmorequietly,aremoreefficientandaresmallerthansinglephasemotorsofsimilarhprating三相马达具有更好的起动扭矩、运行更平顺、更有效率，并且体积比相同马力的单相马达更小。Ifyouaddmorethanthreephasesitaddsmorecostbutdoesntdeliversignificantperformanceimprovements如果相数多余三个，会增加很多费用，但是性能并没有明显改善。,Threeindividualvoltagephasestypically120degreesoutofphaseofeachother.三个独立的电压相位彼此之间一般相差120度。Threeindividualcurrentphasestypically120degreesoutofphaseofeachother.三个独立的电流相位彼此之间一般相差120度。Voltageandcurrentwilltypicallybeshiftedfromeachotherresultingin“powerfactor”电压和电流的相位一般不一致，所以就有了“功率因数”,VectorRepresentation矢量表示,Notethatthevectorsgointhecounterclockwisedirection,likethecircleinthepreviousslide注意：矢量呈逆时针运动，类似前面例子中的圆周。,FromtheDamtoYourLoad从发电站到负载,FromtheDamtoYourLoad从发电站到负载,HighVoltage(over100kV)isusedfortransmission.All3-phase用于电力传输的高压线路（100kV以上）。全为三相系统,Substationsusetransformerstostepdownthevoltagetomediumvoltage(4160to14kV).PTsareusedtomeasurevoltagelevels.变电站利用变压器将电压变为中压（4160到12kV）。使用PT来测量电压。,Mediumvoltageisusedfordistribution.Mostly3-phase.使用中压进行配电。大多数为三相系统。,MediumVoltageissteppeddownto240or480fordeliverytocustomers.中压又被变为240或480伏的电压，然后传输给用户。,Fusesandcircuitbreakers保险和电路断路器Protectiverelays保护继电器Lightningarrestors避雷器Switches电闸“Reclosure”自动开关,FromtheDamtoYourLoad从发电站到负载,TransformerConnections变压器的连接,Single-phasesystems单相系统,Three-phase,Fourwiresystems三相、四线系统,Three-phase,Threewiresystems三相、三线系统,DeltaConfiguration三角型配置,Comprisedof3voltagesand3currents.由三个电压和三个电流组成NoNeutralwire.无零线Sometimeshasagroundwire.有时有地线Voltageismeasureas“phasetophase”.测量的电压为“相相”电压Typically480vrms.一般为480vrms.,WyeConfigurationY型配置,AlmostallcommercialandlightindustrialloadsaresuppliedbyGrounded-Y(4-wireY)transformers.几乎所有的商业和照明领域的负载都是由接地的Y型（4线Y型）配置的变压器供电的,Comprisedof3voltagesand3currents.由三个电压三个电流组成Neutralwireandgroundwire.零线和地线TheWyedeliverstwostablevoltagelevelsfromonetransformer在Y性配置下，变压器可以提供两个电压PhasetoNeutralmaybeusedforsmallerloads相零电压，小的负载可以使用这个电压Phasetophasemaybeusedforlargerloadsorlongerwiringruns相相电压，大负载或配线较长时可以使用该电压,VoltageLevels电压,Standardvoltagelevelsvarybycountry各个国家的标准电压会不一样Mostdistributionwithinbuildingsis120Vto480V建筑物内的绝大多数配电系统为120V到480VResidentialstandardsvaryconsiderably各个国家与住宅有关的标准也不一样US,Canada,Mexicousea240Vsinglephasesystem美国、加拿大、墨西哥使用240V的单相系统Europe,China,othersuse230Vsingleor3-phase欧洲、中国以及其它国家使用230V单相或三相系统TypicalWyephase-to-phaseandphase-to-neutralvoltagesare典型的Y型配置下相相和相零电压如下240/120V(US,Canada,Mexico)240/120V（美国、加拿大、墨西哥）400/230V(China,Europe)400/230V（中国、欧洲）480/277V(US,Canada,Mexico)480/277V（美国、加拿大、墨西哥）Voltagesfrom1kVto100kVareusedtoservelargecommercialbuildingsandforutilitydistribution1kV到100kV的电压一般用于大的商业建筑和公用配电系统Voltagesover100kVareusedfortransmission超过100kV的电压一般用于电力传输,ColorCodes色标,Variesbycountryandterritory.各个国家和地区不一致Notalwaysdonecorrectly.不一定都正确使用Busbarusuallynotlabeled.通常并不标注母线AustraliaElectricalPowerSystemsQualityDugan,McGranahan,Beaty；“电力系统的质量”,PowerProblems电能问题,Voltagesagsandoutages电压骤降或断电Overcurrent(trippingCBs)过流（启动断路器）UtilityBills电费Energyconsumption能量消耗PeakDemand最高负荷PowerFactorPenalties功率因数的影响Voltageswells电压骤升Transients瞬态电压Voltageimbalance/unbalance电压失衡/紊乱Excessiveharmonics谐波过多Flicker闪变Noise噪声Groundcurrentsorpoorgrounding接地电流或接地不良,SeverityofVoltageEvents电压时间的安全性,MostPowerQualityeventsarereallyvoltageevents.大多数电能质量时间其实是电压事件Severityofavoltageeventischaracterizedbymagnitudeandduration.电压时间的严重程度是由幅度和持续时间表示的。Thelargerthechange,andthelongerittakesplace,themorelikelyitisthatequipmentwillmalfunction.事件的变化越大、持续的时间越长，设备就越有可能出现故障ITIC/CBEMAcurvesplotmagnitudeanddurationofeventsthatarelikelytocauseproblemswithcomputerequipment.ITIC/CBEMA曲线用来绘制可能会导致计算机设备出现故障的事件的幅度和持续时间。,LetsTalkAboutStandards关于标准,TherearetwoimportantstandardsthatinfluencedthedesignoftheFluke430有两个重要的标准影响着Fluke430设计IEC61000-4-30“TestingandMeasurementTechniquesforPowerQualityMeasurementMethods.”IEC61000-4-30“电能质量测量的测试和测量技术”EN50160“VoltageCharacteristicsofElectricitySuppliedbyPublicDistributionSystems”EN50160“公共配电系统所供电力的电压特征”EN50160doesnotmandateIEC-61000-4-30measurementtechniques,butitisconsistentEN50160标准对IEC-61000-4-30测量技术并没有要求，但是一致的。Bothstandardsareexertingstronginfluenceworldwide!两个标准对全世界有不同凡响的影响！,IEC61000-4-30,IEC61000-4-30TestingandMeasurementTechniquesforPowerQualityMeasurementMethods.IEC61000-4-30“电能质量测量的测试和测量技术”ReferstootherstandardslikeIEC61000-4-7(Harmonics)andIEC61000-4-15(Flicker)引用了其它标准，如IEC61000-4-7(谐波)和IEC61000-4-15(闪变)Twoclassesofmeasurementperformance两种类型的测量性能ClassA,precise,suitableforcompliancetestandsolvingdisputesincourtA类，精确,适用于兼容性测试和解决争议ClassBfortroubleshootingandstatisticssurveysB类，用于故障诊断和统计测量,InthispresentationthissymbolmeansIEC6100-4-30istheguidingforce在本幻灯片中，该标志表示以IEC6100-4-30为导向,TheFluke430SeriesmeetsmanyofthespecsforclassAandallspecsforClassB!Fluke430系列满足多数A类技术指标要求和全部的B类技术指标要求！,IEC61000-4-30DefinitionsIEC61000-4-30的定义,Powerfrequency电源频率Magnitudeofthesupplyvoltage电源电压的幅度Flicker闪变Supply-voltagedipsandswells电源电压骤降和骤升Voltageinterruptions断电Transientvoltages瞬态电压Supplyvoltageunbalance电源电压失衡Voltageharmonics电压谐波Voltageinterharmonics电压谐间波Mainssignalingvoltageonthesupplyvoltage电源电压上的主信号电压Rapidvoltagechanges快速的电压变化Measurementofunderdeviationandoverdeviationparameters欠偏离和过偏离参数的测量Current电流,IEC61000-4-30“Aggregation”IEC61000-4-30“集合”,Measurementaggregationovertimeintervals时间间隔上的测量集合Basicmeasurementtimeintervalis基本的测量时间间隔为10-cyclesfor50Hzsystems对50Hz的系统为10个周期12-cyclesfor60Hzsystems对60Hz的系统为12个周期Measurementtimeintervalsareaggregatedover3differenttimeintervals:测量时间间隔由3个不同的时间间隔组成：3-sinterval(150cyclesfor50Hznominalor180cyclesfor60Hznominal),3-s间隔（对于标称为50Hz的电压为150个周期，对于标称为60Hz的电压为180个周期）10-mininterval,10-min间隔2-hinterval.2-h间隔Manymeasurementslikermsvoltageandharmonicsaresimplyaveraged.Others,like,flicker,arentquitesosimple.许多测量参数如rms电压和谐波是经过简单平均得到的。其它参数如闪变并没那么简单。,Theuses10minuteaggregationforvoltage,harmonics,flickercheckinginSystemMonitorMode.Pltisa2-hourmeasurement.Fluke430使用10分钟间隔在系统监控模式下进行电压、谐波和闪变检查。Plt为2小时间隔测量的。,IEC61000-4-30“Flagging”IEC61000-4-30“标记”,Duringdip,swell,orinterruption,otherparametersmaybeunreliable?在骤降、骤升或断电期间，其它参数是不是可能不可靠？Flaggingconceptavoidscountingasingleeventmorethanonce通过标记，避免了重复计算某一信号事件Flaggingisonlytriggeredbydips,swells,andinterruptions.标记仅由骤降、骤升和断电事件触发Applicableformeasurementofpowerfrequency,voltagemagnitude,flicker,supplyvoltageunbalance,voltageharmonics,voltageinterharmonics.适用于频率、电压幅度、闪变、电源电压失衡、电压谐波、电压谐间波的测量AflaggedvalueisindicatedontheFluke430byasmallflagintheupperrightofthedisplay.被标志的值由Fluke430显示屏右上角的标志表示。,TheFluke430SeriesFluke430系列,TheFastestWaytoPinpointPowerQualityProblems诊断细微的电能质量问题的最快途径,PowerToGo,Full3-phasemeasurement!完整的3相测量！4voltageinputsthreephasesandneutral.4currentinputsallowmeasurementsonthreephasesandneutral.4个电压输入：三个相电压和零线电压。4个电流输入，可以测量三个相电流和零线电流。Runsforover7hoursonNiMHbatteriesorrunsonlinepower.Takeitanywhere.在由镍氢电池供电时，可使用7个小时以上；也可以由市电供电。可以拿到任何地方进行测量。Includeseverythingyouneedtogetdowntowork:voltageclipsandleads,currentclamps,andcarryingcase包括测量所需的一切功能：电压夹子和测试线、电流钳和便携包Fluke434includesFlukeViewSoftwareandinterfacecableFluke434包括FlukeView软件和接口电缆,SeeWhatYouveBeenMissing可以得到的新功能,Highresolution,colorLCDforviewingmultipleparametersandmultiplephasessimultaneously.高分辨率、彩色LCD，可以同时观察多个参数和多个相信号。SelectfromIndustryStandardcolorcodingorChooseyourown.Letsyoueasilycorrelateconnectionsandreadings可以选择工业标准的色标，或自己选择颜色。可以方便地正确连接和度数。,GetAnswersFast!答案就是：快！,Fast-update,high-resolutionscopedisplayshowsvoltageandcurrentwaveformsforallthreephasesandneutral.快速刷新、高分辨率的示波器显示全部三个相信号和零线信号的电压和电流波形。Toggletophasordisplayatanytimeforaquickcheckofphasesequence.在任何时候都可以切换到矢量显示，快速检查相序。,AllBasicMeasurements全部的基本测量,RMSandpeakvoltage,RMSandpeakcurrent,crestfactorforallphasesandneutralRMS和峰值电压、RMS和峰值电流、所有相信号和零线信号的波峰因数Frequency频率,Watts,VA,VARs瓦特、伏安、乏PowerFactoranddisplacementpowerfactor功率因数和位移功率因数,AutoTrending自动趋势绘图,AutomatictrendingstartsinthebackgroundwhenyouselectV-A-Hz,Power,orHarmonics.当选择了V-A-Hz、功率或谐波功能时，则在后台启动自动趋势绘图功能Switchbetweennumericreadin