PQ测量仪器和技术基础PPT课件

1、Electricity is generated by conductors rotating though a magnetic field电是由在磁场中旋转的导体电是由在磁场中旋转的导体产生的产生的Pick a point on a circle, rotating counterclockwise at a fixed speed. When the angle is small the change in height is rapid. As the angle increases towards 90 the change in height slows. The distance

2、 from the “the horizon” sweeps out a sine wave. 在圆周上选一个点，该点以固定速率在在圆周上选一个点，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；度比较小时，高度的变化就比较明显；当旋转角度向当旋转角度向90方向增长时，方向增长时， 高度高度的变化也组件减缓。偏离的变化也组件减缓。偏离“水平水平”方向方向的高度即形成了一个正弦波。的高度即形成了一个正弦波。Why Sine Waves ?为什么会是正弦波？为什么会是正弦波？第1页/共30页Why 3-Phase?为什么为三相？

3、为什么为三相？-700.00-600.00-500.00-400.00-300.00-200.00-100.000.00100.00200.00300.00400.00500.00600.00700.0004590135180225270315360DegreesV (phase to phase)A-BA-CThree Phase Grounded-500.00-400.00-300.00-200.00-100.000.00100.00200.00300.00400.00500.0004590135180225270315360V (ref to earth)ABC At any insta

4、nt the net current on the neutral is zero. Try it!在任何情况下，零线上的净电流为零。试试看！ Three phase motors have better starting torque, run more quietly, are more efficient and are smaller than singlephase motors of similar hp rating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。 If you add more than three phases it add

5、s more cost but doesnt deliver significant performance improvements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。Three individual voltage phases typically 120 degrees out of phase of each other.三个独立的电压相位彼此之间一般相差120度。Three individual current phases typically 120 degrees out of phase of each other.三个独立的电流相位彼此之间一般相差120

6、度。Voltage and current will typically be shifted from each other resulting in “power factor”电压和电流的相位一般不一致，所以就有了“功率因数”第2页/共30页Vector Representation矢量表示矢量表示 Note that the vectors go in the counterclockwise direction, like the circle in the previous slide注意：矢量呈逆时针运动，类似前面例子中的圆周。注意：矢量呈逆时针运动，类似前面例子中的圆周。第3页

7、/共30页From the Dam to Your Load从发电站到负载从发电站到负载第4页/共30页From the Dam to Your Load从发电站到负载从发电站到负载High Voltage (over 100kV) is used for transmission. All 3-phase用于电力传输的高压用于电力传输的高压线路（线路（100kV以上）。以上）。全为三相系统全为三相系统Substations use transformers to step down the voltage to medium voltage (4160 to 14kV).PTs are us

8、ed to measure voltage levels.变电站利用变压器将电压变变电站利用变压器将电压变为中压（为中压（4160到到12kV）。）。使用使用PT来测量电压。来测量电压。Medium voltage is used for distribution. Mostly 3-phase.使用中压进行配电。大使用中压进行配电。大多数为三相系统。多数为三相系统。Medium Voltage is stepped down to 240 or 480 for delivery to customers.中压又被变为中压又被变为240或或480伏的电压，然后传伏的电压，然后传输给用户。输给用

9、户。 Fuses and circuit breakers保险和电路断路器保险和电路断路器 Protective relays保护继电器保护继电器 Lightning arrestors避雷器避雷器 Switches电闸电闸“Reclosure”自动开关自动开关第5页/共30页From the Dam to Your Load从发电站到负载从发电站到负载第6页/共30页Transformer Connections变压器的连接变压器的连接Single-phase systems单相系统单相系统 Three-phase, Four wire systems 三相、四线系统三相、四线系统Three

10、-phase, Three wire systems 三相、三线系统三相、三线系统第7页/共30页Delta Configuration三角型配置三角型配置 Comprised of 3 voltages and 3 currents.由三个电压和三个电流组成 No Neutral wire.无零线 Sometimes has a ground wire.有时有地线 Voltage is measure as “phase to phase”.测量的电压为“相相”电压Typically 480vrms.一般为480vrms.第8页/共30页Wye ConfigurationY型配置型配置Alm

11、ost all commercial and light industrial loads are supplied by Grounded-Y (4-wire Y) transformers. 几乎所有的商业和照明领域的负载都是由几乎所有的商业和照明领域的负载都是由接地的接地的Y型（型（4线线Y型）配置的变压器供电的型）配置的变压器供电的Comprised of 3 voltages and 3 currents.由三个电压三个电流组成Neutral wire and ground wire.零线和地线The Wye delivers two stable voltage levels fr

12、om one transformer在Y性配置下，变压器可以提供两个电压Phase to Neutral may be used for smaller loads相零电压，小的负载可以使用这个电压Phase to phase may be used for larger loads or longer wiring runs相相电压，大负载或配线较长时可以使用该电压第9页/共30页Voltage Levels 电压电压 Standard voltage levels vary by country各个国家的标准电压会不一样 Most distribution within buildings

13、 is 120V to 480V建筑物内的绝大多数配电系统为120V到480V Residential standards vary considerably 各个国家与住宅有关的标准也不一样US, Canada, Mexico use a 240V single phase system美国、加拿大、墨西哥使用240V的单相系统Europe, China, others use 230V single or 3-phase欧洲、中国以及其它国家使用230V单相或三相系统 Typical Wye phase-to-phase and phase-to-neutral voltages are典

14、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） Voltages from 1kV to 100kV are used to serve large commercial buildings and for utility distribution1kV到100kV的电压一般用于大的商业建筑和公用配电系统 Voltages over

15、 100kV are used for transmission超过100kV的电压一般用于电力传输第10页/共30页Color Codes色标色标 Varies by country and territory.各个国家和地区不一致 Not always done correctly.不一定都正确使用 Bus bar usually not labeled.通常并不标注母线Australia & New Zealand:澳大利亚和新西兰：Red / White / Blue / Black / Yellow Green Strip红/白/蓝/黑/黄色卷带USA:美国：Black /

16、Red /Blue / White / Green黑/红/蓝/白/绿Europe:欧洲：Red / Yellow / Blue / Black / Yellow Green strip红/黄/蓝/黑/黄色卷带第11页/共30页Let us speak Power关于功率关于功率Three Kinds of AC Power三种交流功率 True Power (W)有效功率（W） Does useful work做有用功 Reactive Power (VAR)无功功率（VAR） Powers motor magnetic field, charges capacitor驱动马达磁场、给电容充电

17、 Apparent Power (VA)视在功率（VA） System capacity系统负载量PF = WattsVolt-AmpsHead = VARs头部=乏Beer = Watts啤酒=瓦特Glass = VA玻璃杯=伏安第12页/共30页Power Triangle功率三角形功率三角形Motors require “lagging” VARs, reducing PF.Greater system capacity (VA) is required.马达需要马达需要“滞后滞后” 乏，乏，导致功率因数降低，需导致功率因数降低，需要更大的系统负载量要更大的系统负载量（VA）。）。Cap

18、s supply “leading” VARs, improving PF, reducing VA requirement.电容能使乏电容能使乏“提前提前”，提高功率因数，减小所提高功率因数，减小所需的伏安。需的伏安。Capsreduce PF电容降低了电容降低了PFReactivePower (VARs)无功功率无功功率（乏）（乏）True Power (Watts)有效功率（瓦有效功率（瓦特）特）Apparent Power (VA)视在功率（伏视在功率（伏安）安）VAWattsrPowerFacto 第13页/共30页What is Power Quality什么是电能质量什么是电能质

19、量“Any power problem manifested in voltage, current, or frequency deviations that results in failure or missed operation of utility or end user equipment”“电能质量就是指出现在导致公用设施或最终用户设备故障或工作不正常的电压、电流或频率偏移上的任何电能问题。Dugan, McGranahan, Beaty; Electrical Power Systems Quality Dugan, McGranahan, Beaty；“电力系统的质量”第1

20、4页/共30页Power Problems电能问题电能问题Voltage sags and outages电压骤降或断电Overcurrent (tripping CBs)过流（启动断路器）Utility Bills电费Energy consumption能量消耗Peak Demand最高负荷Power Factor Penalties功率因数的影响Voltage swells电压骤升Transients瞬态电压Voltage imbalance/unbalance电压失衡/紊乱Excessive harmonics谐波过多Flicker闪变Noise噪声Ground currents or

21、poor grounding接地电流或接地不良第15页/共30页Severity of Voltage Events电压时间的安全性电压时间的安全性Most Power Quality events are really voltage events.大多数电能质量时间其实是电压事件Severity of a voltage event is characterized by magnitude and duration.电压时间的严重程度是由幅度和持续时间表示的。The larger the change, and the longer it takes place, the more li

22、kely it is that equipment will malfunction.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/CBEMA curves plot magnitude and duration of events that are likely to cause problems with computer equipment. 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。第16页/共30页Lets Talk About Standards关于标准关于标准 There are two important standa

23、rds that influenced the design of the Fluke 430有两个重要的标准影响着Fluke 430设计 IEC 61000-4-30 “Testing and Measurement Techniques for Power Quality Measurement Methods.”IEC 61000-4-30 “电能质量测量的测试和测量技术” EN50160 “Voltage Characteristics of Electricity Supplied by Public Distribution Systems”EN50160 “公共配电系统所供电力的

24、电压特征” EN50160 does not mandate IEC-61000-4-30 measurement techniques, but it is consistentEN50160标准对IEC-61000-4-30测量技术并没有要求，但是一致的。 Both standards are exerting strong influence worldwide!两个标准对全世界有不同凡响的影响！第17页/共30页IEC61000-4-30 IEC61000-4-30 Testing and Measurement Techniques for Power Quality Measure

25、ment Methods.IEC61000-4-30 “电能质量测量的测试和测量技术” Refers to other standards like IEC61000-4-7 (Harmonics) and IEC61000-4-15 (Flicker)引用了其它标准，如IEC61000-4-7 (谐波) 和 IEC61000-4-15 (闪变) Two classes of measurement performance 两种类型的测量性能 Class A, precise, suitable for compliance test and solving disputes in court

26、A类，精确,适用于兼容性测试和解决争议 Class B for troubleshooting and statistics surveysB类，用于故障诊断和统计测量IEC61000In this presentation this symbol means IEC 6100-4-30 is the guiding force在本幻灯片中，该标志表示以在本幻灯片中，该标志表示以IEC 6100-4-30 为导向为导向The Fluke 430 Series meets many of the specs for class A and all specs for Class B!Fluke

27、430 系列满足多数系列满足多数A类技术指标要求和全部的类技术指标要求和全部的B类技术指标要求！类技术指标要求！第18页/共30页IEC 61000-4-30 DefinitionsIEC 61000-4-30的定义的定义 Power frequency 电源频率Magnitude of the supply voltage 电源电压的幅度Flicker闪变Supply-voltage dips and swells电源电压骤降和骤升Voltage interruptions 断电Transient voltages 瞬态电压Supply voltage unbalance电源电压失衡Volt

28、age harmonics电压谐波Voltage interharmonics电压谐间波Mains signaling voltage on the supply voltage电源电压上的主信号电压Rapid voltage changes快速的电压变化Measurement of underdeviation and overdeviation parameters 欠偏离和过偏离参数的测量Current电流IEC61000第19页/共30页IEC61000-4-30 “Aggregation”IEC61000-4-30 “集合集合”Measurement aggregation over

29、 time intervals时间间隔上的测量集合时间间隔上的测量集合Basic measurement time interval is基本的测量时间间隔为 10-cycles for 50 Hz systems对50 Hz 的系统为10个周期 12-cycles for 60 Hz systems对60 Hz的系统为12个周期Measurement time intervals are aggregated over 3 different time intervals:测量时间间隔由3个不同的时间间隔组成： 3-s interval (150 cycles for 50 Hz nomin

30、al or 180 cycles for 60 Hz nominal), 3-s间隔（对于标称为50 Hz的电压为150个周期，对于标称为60 Hz的电压为180个周期） 10-min interval, 10-min间隔 2-h interval. 2-h间隔Many measurements like rms voltage and harmonics are simply averaged. Others, like, flicker, arent quite so simple.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。IEC61000The us

31、es 10 minute aggregation for voltage, harmonics, flicker checking in System Monitor Mode. Plt is a 2-hour measurement.Fluke 430 使用使用10分钟间隔在系统监控模式下进行电压、谐分钟间隔在系统监控模式下进行电压、谐波和闪变检查。波和闪变检查。Plt为为2小时间隔测量的。小时间隔测量的。第20页/共30页IEC61000-4-30 “Flagging”IEC61000-4-30“标记标记”During dip, swell, or interruption, other

32、parameters may be unreliable?在骤降、骤升或断电期间，其它参数是不是可能不可靠？Flagging concept avoids counting a single event more than once通过标记，避免了重复计算某一信号事件Flagging is only triggered by dips, swells, and interruptions.标记仅由骤降、骤升和断电事件触发Applicable for measurement of power frequency, voltage magnitude, flicker, supply voltag

33、e unbalance, voltage harmonics, voltage interharmonics.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A flagged value is indicated on the Fluke 430 by a small flag in the upper right of the display.被标志的值由Fluke 430 显示屏右上角的标志表示。IEC61000第21页/共30页The Fluke 430 SeriesFluke 430 系列系列The Fastest Way to Pinpoint Power Qu

34、ality Problems诊断细微的电能质量问题的最快途径第22页/共30页Power To GoFull 3-phase measurement! 完整的3相测量！ 4 voltage inputs three phases and neutral. 4 current inputs allow measurements on three phases and neutral. 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。Runs for over 7 hours on NiMH batteries or runs on line power. Take

35、 it anywhere. 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。Includes everything you need to get down to work: voltage clips and leads, current clamps, and carrying case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Fluke 434 includes FlukeView Software and interface cableFluke 434 包括FlukeView软件和接口电缆第23页/共30页See What Youve

36、 Been Missing可以得到的新功能可以得到的新功能 High resolution, color LCD for viewing multiple parameters and multiple phases simultaneously.高分辨率、彩色LCD，可以同时观察多个参数和多个相信号。 Select from Industry Standard color coding or Choose your own. Lets you easily correlate connections and readings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。第

37、24页/共30页Get Answers Fast!答案就是：快！答案就是：快！ Fast-update, high-resolution scope display shows voltage and current waveforms for all three phases and neutral.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。 Toggle to phasor display at any time for a quick check of phase sequence.在任何时候都可以切换到矢量显示，快速检查相序。第25页/共30页All Basic Measurements全部的基本测量全部的基本测量RMS and peak voltage, RMS and peak current, crest factor for all phases and neutralRMS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Power Factor and displacement power factor功率因数和位移功率因数第26页/共30页Auto Trending自动趋势绘图自动趋势绘图Automatic