Power Quality Testing

Transcription

1 Power Quality Testig

2 INTRODUCTION TO POWER QUALITY Both atural ad mamade drivers are spurrig ot oly techological growth but are chagig the ature of the electric grid. Cocers over global warmig are oly beig compouded by the cotiuig billio dollar weather evets. This is actig as a catalyst for the gree reform ad beig realized i the growth of distributed geeratio (DG). Globally, the growth of reewable eergy sources is risig. We see more photovoltaic (PV) geeratio as well as more wid power geeratio. As these chages are implemeted to improve reliability, they create ew power quality issues. As the grid moderizes, we see the emergece of ew power quality problems. We see reewable sources as well as high efficiecy electroics ad ew lightig techologies creatig power quality pheomea such as rapid voltage chage (RVC), ubalace, high frequecy harmoics, frequecy shiftig betwee phases, ad source reversals. These issues ca lead to trasformers ad motors heatig up, equipmet trippig out, lights of all types flickerig, high eutral curret ad much more. As the smart grid grows, we see more commuicatios over power lies (mais sigalig) to help maitai reliability durig peak times. This requires high-ed, smart ad simple-to-use power quality aalyzers such as the Megger MPQ Aalyzer. They have the power to measure all power quality problems from high-speed trasiets to RVC, high frequecy harmoics as well as mais sigalig ad much more. The Megger power quality aalyzer is smart eough to recogize the CT coected as well as the CT rage ad let you kow they are coected properly. The o-board data aalysis o the large color display makes aalysis simple ad easy for ayoe to use. Let the MPQ Aalyzer be your expert. 2 Power Quality Testig

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4 MPQ1000 The MPQ1000 is a hadheld 3-phase power quality aalyzer that makes power quality aalysis easier ad more efficiet. It is i compliace with IEC , Class A ad is rated CATIV at 600V. It ca be used for a wide variety of applicatios icludig substatio moitorig, equipmet ad breaker trippig, load studies ad load balacig as well as for switchgear ad compoet failure. This highly ituitive uit delivers umatched capability i a smart ergoomic platform. I both the scope ad DVM modes, the versatile MPQ1000 ca record power, eergy, RMS, sags, swells, trasiets dow to 1 microsecod, harmoics, iter-harmoics, harmoic directio, THD, TDD, flicker, ad much more. Automatic CT recogitio meas ever havig the uit programmed for a icorrect rage. Coectio verificatio esures the uit is cofigured correctly ad you get the data you eed o wasted recordigs. O-board data aalysis saves time by allowig a immediate examiatio of data before leavig the site. Multiple commuicatio methods (USB, Etheret, USB stick or SD card) allow for flexible ad coveiet operatio The expaded 1000 V ac rage allows for more applicatio; o eed for a secod uit V dc measuremet allows testig ad aalysis of reewable applicatios dismissig the eed for additioal equipmet. 600 V assures a safe uit for all applicatios Automatic CT recogitio Automatic coectio verificatio O-board data aalysis SD card ad USB stick support 1000 V ac ad 1000 V dc rage Scope ad DMM modes 600 V IEC Class A compliat Made i the USA Full-featured Class A compliat (all parameters) esures the recordig of correct values. Timed waveform capture allows for the takig of PQ evets ad periodic waveforms at the same time. Free software icluded meas o licese or dogle required. 4 Power Quality Testig

5 APPLICATIONS Usig experiece gaied from supplyig a multitude of aalyzers to a large umber of utilities, idustries ad service providers, Megger has desiged the most versatile uit available today. Some of the applicatios iclude the followig: Compliace testig to ay PQ stadard Power factor studies Load studies ad load balacig Billig verificatio Substatio moitorig Capacitor bak sizig Trasformer aalysis ad de-ratig Motor troubleshootig ad irush testig Switchgear ad compoet failure Trippig breakers Equipmet trippig offlie Dimmig/surgig lightig Lamp flicker aalysis Neutral overheatig Solar (PV) aalysis 5

6 MPQ SELECTION GUIDE MPQ1000 Power from V (50 Hz/60 Hz) 4 voltage chaels Curret chaels 4 Fully Class A compliat (IEC ad IEEE1159) 0 to 1000 V ac/dc measuremet rage RMS voltage ad curret DC voltage ad DC curret (requires DC CT) Power parameters (KW, KVAR, KVA, DPF, TPF) Phase agles Eergy parameters (KWH, KVARH, KVAH) Voltage dips (sags) ad swells Curret dips (sags) ad swells Trasiet dow to 1 msec IEC ubalace (IEC ) ANSII ubalace Total harmoic distortio (THD) Total demad distortio (TDD) Harmoics Iter-harmoics Harmoic directio Mai sigalig recordig IEC flicker (IEC ) Rapid voltage chage Phase agle deviatio Frequecy Auto CT idetificatio Record deviatio O-board data aalysis O-board scope Real-time harmoics/iter-harmoics bar charts USB commuicatios port Etheret port USB ad SD card support 6 Power Quality Testig

7 METROSOFT Metrosoft is a powerful PC-based software that supports local ad remote commuicatios to the MPQ1000. It will automatically create uit cofiguratios based o the power quality problem beig ivestigated. This assures that the pheomeo that ca cause the power quality difficulty is recorded. The free software requires o licese ad offers advaced chartig, advaced waveform ad advaced harmoic aalysis. Record ad Aalyze The Metrosoft software allows the user to aalyze the recorded data o a PC. The software will also automatically aalyze the recorded data based o stadard ad custom templates created by the operator that meet local stadards. Charts ad Reports The operator ca create charts ad reports as well as perform detailed harmoic aalysis of the data through the 128th harmoic order. These ca be used for data aalysis o the PC or be loaded o to the MPQ aalyzer. The aalysis ca the be doe o the MPQ uit itself. 7

8 PQ ACCESSORIES ACCESSORIES MCCV Self-idetifyig, four rage flexible CT. Powered by the aalyzer. 18cm ID. (60A, 600A, 3000A ad 6000A) MCC Self-idetifyig, four rage flexible CT. Powered by the aalyzer. 27cm ID. (60A, 600A, 3000A ad 6000A) CP-5CE-ID Self-idetifyig, split core 5A CT. 20mm (.78 ) ID. CP-20CE-ID Self-idetifyig, split core 20A CT. 20mm (.78 ) ID. CP-100CE-ID Self-idetifyig, split core 100A CT. 20mm (.78 ) ID. CP-1000WCE-ID Self-idetifyig, split core 1000A CT. 50.8mm (2.0 ) ID. CP-600DC-ID Self-idetifyig, split core 600A DC CT. 50.8mm (2.0 ) ID. (AC ad DC) MPQ-1000 Voltage Lead Set Set of 5 voltage lead cables for the MPQ-1000 PQ aalyzer Color Bads Set of multiple color bads. Used for color codig the MPQ-1000 voltage leads. 8 Power Quality Testig

9 Fuse Adapters This fused adapter plugs ito the stadard MPQ leads. (2A Fused icluded) Fuses Stadard 2A fuse for the MPQ fused adapters. Carry Bag Soft sided carry bag for the MPQ aalyzer. This bag fits the MPQ-1000 plus all cables ad a set of 3 curret clamps. PQ Simulator Three phase power quality simulator. Powered off a sigle phase AC adapter. ( / 50 / 60Hz) Create dips (sags), swells, trasiets, harmoics ad flicker. Also create phase shifts as well as leadig ad laggig power factor. Ideal for PQ ad demad traiig. USB Cable USB commuicatios cable for use with MPQ Etheret Cable Etheret commuicatios cable for use with MPQ USB Stick For use with MPQ Trasfer setup cofiguratios ad data files. SD Card For use with MPQ Trasfer setup cofiguratios ad data files. MPQ-1000 Power Adapter Power adapter for the MPQ /60Hz) Plugs ito stadard US, EU ad UK power outlets. Strap for MPQ1000 Pluger Clips 9

10 PQ KITS MPQ1000 BRONZE KIT Eight chael three phase had held PQ aalyzer. Icludes: PQ aalyzer, voltage leads, SD card, USB cable, Etheret cable, uiversal power adaptor ad soft sided carry bag plus voltage lead pluger clips, hagig strap ad 3 CP-100CP-ID 100A split core CTs. MPQ1000 SILVER KIT Eight chael three phase had held PQ aalyzer. Icludes: PQ aalyzer, voltage leads, SD Card, USB cable, Etheret cable, uiversal power adaptor ad soft sided carry bag plus voltage lead pluger clips, hagig strap ad 3 MCCV (four rage flex 18 cm ier diameter (ID) CTs). MPQ1000 GOLD KIT Eight chael three phase had held PQ aalyzer. Icludes: PQ aalyzer, voltage leads, SD Card, USB cable, Etheret cable, uiversal power adaptor ad soft sided carry bag plus voltage lead pluger clips, hagig strap ad 3 MCCV (Wide Diameter 27cm - four rage flex CTs). 10 Power Quality Testig

11 GLOSSARY OF TERMS EFT (Extremely Fast Trasiet) Trasiets that have rise ad fall times i the aosecod regio. Flicker A impressio of usteadiess of the visual sesatio, iduced by a light stimulus with a lumiace fluctuatio over time. Harmoics A siusoidal compoet of a periodic wave or quatity havig a frequecy that is a itegral multiple of the fudametal frequecy. RMS Voltage The root-mea-square value of the voltage, derived from the summatio of the square root of the arithmetic mea (average) of the squares of the origial voltage samples. RVC (Rapid Voltage Chage) A variatio of the RMS or peak value of a voltage betwee two cosecutive levels that is sustaied for a give duratio. Sag/Dip A istataeous or mometary decrease i the steady state RMS value. Imbalace The ratio of the egative sequece compoet of a voltage or curret to the positive sequece compoet of that voltage or curret, typically expressed as a percetage. Iter-Harmoics A harmoic compoet of a periodic quatity that is ot a iteger multiple of the fudametal frequecy that the supply system is operatig. IP54 A measuremet of evirometal protectio that states the igress of dust is ot etirely preveted but will ot eter i sufficiet quatity to iterfere with the satisfactory operatio of the equipmet ad drippig water (vertically fallig drops) shall have o harmful effect. Phase Agle The delay betwee the zero crossig of the fudametal voltage sigal ad the fudametal curret sigal represeted i degrees. Sub-cycle A power quality evet i which the duratio is less tha a cycle. Swell A istataeous or mometary icrease i the steady state RMS value. TDD (Total Demad Distortio) A measuremet of the curret THD takig ito accout the average curret load o the circuit durig the recordig iterval. THD (Total Harmoic Distortio) The ratio of the root-mea-square of the harmoic cotet to the root-mea-square value of the fudametal quatity, expressed as a percet of the fudametal. Trasiet A sudde o-power frequecy chage i the steady state coditio of voltage or curret. Power Factor The ratio of the total power iput, i watts, to the total volt-ampere iput to the coverter. RMS Curret The root-mea-square value of the curret, derived from the summatio of the square root of the arithmetic mea (average) of the squares of the origial curret samples. 11

12 WHAT AND WHY? WHY CLASS A? Differet istrumets ca aggregate their data differetly. This meas that if you have two differet istrumets you ca get differet readigs o each. Which is correct? A Class A istrumet will aggregate the data per the IEC stadard. (Now adopted by IEEE1159.) This meas ay two istrumets that are Class A will get the same measuremets. The majority of reveue meters used today are Class A, as are most moitors i substatios. Therefore, they calculate their RMS voltage per the IEC stadard. A Class A istrumet is eeded i order to get the same measuremets as other Class A meters. WHY AUTO CT ID? It is ot ucommo to fid operators coectig the wrog value CT to the aalyzer. This meas the CT rage selected i the aalyzer s cofiguratio file does ot match the rage of the actual CT coected to the aalyzer. A recordig would be started with the wrog value CT coected. The aalyzer could be left i the field for a week or more. They would retrieve the uit oly to fid that the data was o good. They would the have to correct the aalyzer s cofiguratio ad repeat the test. The auto CT idetificatio will ow let them kow there is a mismatch ad ask them if they would like to adjust / chage the CT or would like the aalyzer to automatically alter the cofiguratio to match the CT rage that is coected. This elimiates the possibility of mismatched curret clamps. WHY CONFIGURATION VERIFICATION? Oe of the most commo problems we see is operators coectig the aalyzer icorrectly. They would start a recordig ad leave the aalyzer for a week or loger. Whe the aalyzer was retrieved, the operator would fid the data was o good. Therefore, they would have to repeat the test, wastig a great deal of time. Cofiguratio verificatio solves this problem. The aalyzer will examie the phase agle of all the chaels ad verify they are correct for the cofiguratio selected. The aalyzer will let the operator kow if chaels are coected icorrectly or if a curret clamp is backwards, esurig proper coectio before the recordig is started. WHY PHASE ANGLE SHIFT DETECTION? I today s moder grid, we ca geerate power from a variety of reewable sources. These ca iclude wid eergy as well as biomass. Some of these sources ca produce a great deal of reactive power. For example, wid turbies use iductio geerators. These draw reactive power from the grid to create their magetic field. Whe the wid is blowig, ad they are producig power, we see good power factors at approximately However, whe the wid is ot blowig they are ot creatig power, but are drawig reactive power. This ca lead to very poor power factors, dow to approximately This ca lead to low voltages i the trasmissio lies. I some cases, these reewable systems eed to be isladed from the grid. Whe they come back o the grid, the phase eeds to syc up. This ca be see as a mometary chage i phasig. The MPQ aalyzer ca record a evet whe it sees a phase shift which ca allow the operator to see whe isladed systems are comig back o lie. WHY IEC AND ANSI UNBALANCE? Today, the recommeded method to measure ubalace is to use the IEC ubalace method which follows the IEC stadard (ow adopted by IEEE1159). This method allows you to see egative sequece or zero sequece ubalace. Sequece compoets provide a better way to aalyze the data ad determie what issues it may be causig. The majority of source-side faults are asymmetrical which meas they will ot oly cause chages i phase magitude but also i phase sequece. The ability to view the chages i phase sequece allow for quicker aalysis. ANSI ubalace is aother method of measurig ubalace. This method averages the phases together, the compares each idividual phase to the average. May utilities may have legacy ANSI ubalace data. WHY THD AND TDD? Whe aalyzig voltage harmoics, the Total Harmoic Distortio (THD) measuremet is a good method to use. THD is the sum of all the harmoics refereced to the fudametal value. The voltage fudametal value is typically always preset. However, the same caot be said of curret. Whe loads tur off, curret drops ad ca drop to ear zero. Whe this occurs, misleadig THD values ca be see o the curret chaels. For example, if there is 1A of harmoics ad 100A of fudametal, the the THD will be 1%. However, if there is 1A of harmoic oise ad the curret drops to 0.5A, the THD ca be 200%, which ca be misleadig. IEEE519 recommeds usig Total Demad Distortio (TDD) whe measurig curret. TDD will referece the total curret harmoics to the maximum 12 Power Quality Testig

13 average curret recorded durig the test iterval, which idicates the referece value will always be valid. Some utilities have their ow referece value they use throughout the grid. The Megger PQ PC software allows them to eter this value to use as a referece whe viewig TDD. WHY EVENT AND TIMED WAVEFORMS? Most power quality aalyzers today will record a waveform whe a out-of-limit evet occurs, such as a dip / sag or a swell. However they may ot capture periodic timed waveforms. If you have a recordig that has o out-of-limit evets the you do ot record ay waveforms. Waveforms tell us a great deal about the system. These are eeded to truly uderstad a system. The MPQ aalyzer will capture both evet-triggered waveforms ad periodic timed waveforms. This esures you always have the iformatio eeded to determie the health of your system. WHAT IS RVC? I today s moder grid power ca be obtaied from may reewable sources. These ca iclude both solar power ad wid power. These particular forms of power do ot supply costat power, meaig their output ca fluctuate. This leads to Rapid Voltage Chages (RVCs) o the power lies. RVCs are typically small chages less tha a dip/sag or swell ad ca happe quickly. RVCs ca lead to problems such as lights flickerig ad equipmet trippig off lie. RVCs ca cause flickerig i ay type of lightig system, ot just icadescet bulbs. May aalyzers record the flicker parameter which uses a weighted curve that is based o the icadescet lamp. Additioally, RVCs ca affect ay type of lamp. WHAT IS MAINS SIGNALING? As the smart grid grows, we will see more ad more commuicatios betwee equipmet. Some of that commuicatio ca be through the use of ripple sigals set over the power lies. Utilities ca use these sigals to tur equipmet o ad off. This allows them to tur off large loads durig peak times ad tur them back o at a later time. Whe these sigals are set, they ca cause some issues. There have bee reports of customer appliaces resoatig whe the sigal is set. There have bee reports of street lights turig o durig the day ad off at ight. The MPQ aalyzer will ot oly detect whe a mais sigalig evet has occurred, but will capture the waveform as well. This meas you ca view i your treded data whe a sigal was set ad view the actual sigal. WHY ANALYZE WAVEFORMS THROUGH 128TH ORDER? AC is coverted to DC usig rectifiers that create harmoics. I additio we ow see DC beig coverted to AC usig iverters. Moder iverters are usig higher switchig frequecies which create higher order harmoics. This is especially true i solar ad wid applicatios where higher order harmoics ca be see. Today, these high frequecy harmoic orders betwee the 39th ad 49th harmoic order ca be see. However, as switchig frequecies icrease, these orders icrease also. The MPQ aalyzer gives us the ability to measure ad aalyze these high frequecy harmoics. WHAT IS INTER HARMONICS? Harmoic frequecies are multiples of the fudametal frequecy. Iter harmoics are harmoic frequecies that are betwee the harmoic orders. Typically, these values would be very low. However, if the iter-harmoic frequecy happes to be at resoace value of a piece of equipmet, it ca be amplified sigificatly. This ca create catastrophic failures i equipmet. Whe equipmet such as capacitor baks are out o a system, a harmoic ad iter-harmoic study should be performed to esure there are o potetial resoace issues. WHY CAPTURE TRANSIENTS DOWN TO 1 MICROSECOND? High speed trasiets have limited eergy because it is a fuctio of time ad a high speed trasiet ca be as small as a microsecod. These trasiets are typically dampeed out by just a few meters of cable. This is why high speed trasiets will typically ot be a issue o distributio lies. However, these ca be a issue i areas where there are limited cable rus. Traditioally, these areas would iclude offshore oil platforms as well as mies. But, ow we see residetial ad small commercial buildigs gettig solar paels. I a wid turbie whe the wid chages, the output of the turbie does ot chage istatly. However, i a solar pael whe the solar radiatio chages, the output of that pael chages immediately. This ca lead to repeatig high speed trasiets. Repeated high speed trasiets ca damage sesitive electroics. There have already bee reports of homeowers havig to replace their microwave oves every 15 moths. The MPQ aalyzer ca capture high speed trasiets dow to 1 microsecod. 13

14 A Power Quality Testig

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16 MPQ1000_BR_US_V01 The word Megger is a registered trademark Copyright 2017 Megger 2621 Va Bure Ave Norristow, PA USA T: F: