eppe cx Requiremets to be met by a measurig system for efficietly moitorig supply systems ad techical equipmet Dipl.-Ig. Timo Wild MBA, Product Maager Fault Recordig & Power Quality, KoCoS Messtechik AG Special Topic As etwork operators ad cosumers become more ad more aware of the importace of the security of supply i electrical power systems, they are becomig icreasigly iterested i the cotiuous measuremet of power quality. I order to idetify problems at a early stage ad to be able to take appropriate prevetative measures, the first step is to use a suitable measurig system to closely aalyse the supply system or techical equipmet over a loger time period. Depedig o the specific facility ad applicatio, the requiremets to be met by a suitable measurig system are very varied ad iclude a wide rage of differet measuremet fuctios. A high quality of supply is extremely importat for electrical power utility compaies ad idustrial customers alike. For may maufacturig processes, poor power quality ca lead to costly productio outages ad eve destroy plats ad machiery i some cases. Some examples of the cosequeces of power system disturbaces: Malfuctioig of the cotrol electroics of machies Productio outages System crashes Melted coductors Overheated motors, motors which do ot ru smoothly Overloadig or fires Ucotrolled trippig of switch discoectors or fuses Damage to compesatio equipmet Flickerig screes Corrosio of coduits ad earthig systems Problems with data etworks Data loss Flickerig lights Uexplaied rises i eergy costs Dager to people ad property Drop i performace of machiery ad plats, high losses Reduced equipmet lifetime Miimum requiremets for power quality are defied i the EN 50160 stadard, Voltage characteristics of electricity supplied by public distributio systems. Cotiuous moitorig with referece to the characteristics specified i this stadard should be carried out as a matter of priciple at critical odes. Oly whe appropriate measuremet data is available over a loger time period is it possible to draw coclusios about the quality of the power system by performig meaigful aalyses ad take ay ameliorative measures which may be required. Measuremets made usig portable measurig devices are limited i their ability to provide data for meaigful aalysis as the period of time measured oly costitutes a small sample ad disturbaces usually occur sporadically. The additioal storage ad aalysis of evirometal factors is becomig icreasigly relevat, particularly for measuremets i the reewable eergy sector (PV systems, wid power plats, etc.) ad i idustrial plats. Factors such as light irradiatio, ambiet temperature, module temperature, humidity, wid speed, wid directio, soud itesity, motor speed, geerator temperature, etc. ca provide helpful iformatio for aalysis or fault diagostics. Requiremets to be met by the moitorig system The employees of idustrial cocers ad etwork operators alike have less ad less time to devote to problems coected with power quality. Comprehesive power quality aalysis ofte proves difficult to carry out i practice because of the costat icrease i the workload of idividual employees, ufortuately caused i part by cutbacks i persoel, coupled with a lack of specialist kowledge. This makes it all the more importat for measurig systems to be as simple as possible to cofigure. It must be possible to cofigure stadard measuremets, such as measuremets to EN 50160, at the touch of a butto. What is more, a aalysis tool must be able to fulfil a automatic evaluatio i accordace with predefied guidelies ad preset the result i a report. 2
Fully automated moitorig systems cotiually trasfer the measured data to a cetral data system ad perform evaluatio automatically. Should a fault occur, a built-i alarm system iforms the employees resposible who ca the take appropriate measures. Service compaies like KoCoS Egieerig GmbH ca help with carryig out aalysis or determiig effective remedial measures. Structure of a efficiet measurig system Some of the techical prerequisites for measurig systems used for log-term power systems aalysis are listed below: Itegratio i various commuicatio etworks Easy istallatio ad operatio of the measurig device Absolute sychroisatio of data acquisitio High-accuracy measurig device Secure data acquisitio Large measuremet data memory Dual-processor system for data security Cetral evaluatio ad moitorig Number of aalog ad biary chaels commesurate with the measuremet task I order to be able to aalyse the power quality precisely, at least four voltage chaels ad four curret chaels with a accuracy of at least 0.1% are required. The fourth chael eables additioal measuremet of the curret i the eutral coductor, for example. This ca be importat for detectig overloadig of the eutral coductor. I additio, sesor measuremet iputs for moitorig evirometal coditios are also required. I the case of a fault, this additioal measuremet data is helpful for the purposes of aalysis ad for the determiatio of remedial measures, especially whe a fault has bee caused by a umber of differet factors. Oe measurig system which meets ad exceeds the abovemetioed requiremets is the EPPE CX power quality aalyser made by KoCoS Messtechik AG. This measurig system offers a choice of three differet aalog modules ad a additioal sesor module, makig it extremely flexible. The aalog iputs have a accuracy of 0.05% ad are geerally sampled at a rate of 200 khz. This allows high-resolutio aalyses to be carried out. Aalog module 1: 4 x 600 V (L-N), 4 x 600 V (L-N) (measuremets of two voltage systems) Aalog module 2: 4 x 600 V (L-N), 4 x 40 A (measuremets o protectio or measuremet trasformers) Aalog module 3: 4 x 600 V (L-N), 4 x 3 V (measuremets via exteral curret sesors) Sesor module: 8 x aalog iputs (300 V/10 V/2 V/20 ma) 2 x temperature iputs 1 x aalog output Furthermore, a sufficiet umber of biary iputs should be available with a measurig rage adequate for the applicatio i order to record the status of breaker positios or idustrial machies, for example. Status recordigs of this kid ca provide useful iformatio for subsequet troubleshootig. If the measurig system is coected to a cotrol system, freely cofigurable relay outputs should be available which ca be used for status ad alarm sigals. Fig. 1: EPPE CX power quality aalyser Fig. 2: EPPE CX coectios 2
UW Berdorf GPS ok PQ o DFR o Störschriebe: 5 Special Topic GPS time sychroisatio Mobile measuremet Iterlik Gateway Network Iterlik Gateway UMTS router UMTS router Database Iteret USB flash drive Mobile etwork Evaluatio computer Fig. 3: Commuicatio ad time sychroisatio model Operatig, cofiguratio ad evaluatio computer Iteral emergecy power supply Power quality aalysers are usually coected to a secure power supply. If this is ot possible with certai applicatios, the the measurig device must be equipped with a iteral emergecy power supply i order to be able to record the loss of voltage. However, the battery used i most measurig devices has the disadvatage that it must be replaced after a specified period of time ad this ca ofte oly be doe by the maufacturer. To make matters worse, if there is o battery moitorig fuctioality, the user is ot eve aware of the situatio ad oly fids out whe a power failure occurs ad o recordig is made. The EPPE CX power quality aalyser provides a better solutio with a emergecy power supply which is completely maiteace-free. Commuicatio I order to be able to trasfer measuremet data, the measurig system must be capable of beig itegrated i ay kid of commuicatio etwork, icludig wireless etwork structures. The use of UMTS/LTE routers is ow very popular i this type of situatio. The measuremet data ca be trasferred quickly ad easily to a database via the mobile etwork without havig to use a wired etwork. Aother, cheaper solutio is to dowload the data regularly with the aid of a USB flash drive or laptop. However, with this method it is ot possible for the user to be otified should a fault occur. A sesible solutio is to copy the measuremet data regularly from the measurig system to a database at pre-defied itervals i order to esure fast access at all times. The EPPE CX power quality aalyser is equipped with all commo commuicatios iterfaces, such as RS232, RS485, electrical Etheret, optical Etheret (FO) ad USB (active/passive). Data trasfer with optical Etheret over optical fibre has the major advatage of beig particularly isusceptible to iterferece. The trasfer of data is ot affected by exteral electrical or electro-magetic iterferece fields. The acquisitio of measuremet values is decoupled from the operatig ad commuicatio process i the device by meas of a dual processor system, esurig that the process of acquirig ad savig data is secure too. As well as beig saved i the database, the data ca also be saved i each idividual device for a certai period of time before beig overwritte if the measurig systems feature a circular buffer. 3
The memory capacity of the measurig system should be capable of recordig data for a period of at least oe year. For itegratio i substatio cotrol or other systems, the measurig system should feature a rage of commuicatios services such as Modbus or the iteratioal IEC 61850 stadard which is accepted all over the world. Time sychroisatio Power quality measuremets with wide area coverage call for the values measured by all devices to be recorded absolutely simultaeously. The measuremet results of a umber of measurig systems ca oly be moitored ad aalysed simultaeously if a suitable method of time sychroisatio is employed. Which method of sychroisatio is most suitable from a techical ad ecoomic poit of view depeds o the specific coditios at the idividual locatio. The basic versio of the EPPE CX already icludes all commo time sychroisatio iterfaces: Iteral GPS receiver Electrical GPS telegram ad time pulse iput DCF77 pulse telegram iput Secods/miutes pulse iput IRIG-B iput NTP/SNTP sychroisatio via the commuicatio etwork Iterlik bus for etworkig several devices This meas that the user ca select or chage the type of sychroisatio o site without havig to make ay chages to the hardware of the device. Measuremet fuctios Which specific measuremet fuctios are required always depeds o the measuremet task or applicatio. If a simple measuremet to the Europea EN 50160 stadard is eeded, oly the Power Quality Recordig ad Evet Recordig measuremet fuctios are required. Other measuremet fuctios ca deliver useful iformatio for more accurate ivestigatios of systems ad detailed aalysis of the causes of a disturbace. Power quality recordig The cotiuous recordig of all power system parameters allows comprehesive power quality aalysis to DIN EN 50160 or quality criteria defied by the idividual user. Automatic evaluatio ad the creatio of quality reports as PDF files make it easy to provide proof of quality wheever required, eve without specialist kowledge. Cotiuous data recordig The data logger fuctio records measuremet data cotiuously. The recorded data ca be dowloaded to a cetral computer without iterruptig the measuremet. As a result, data ca be recorded cotiuously for a umber of years. Log-term recordigs provide comprehesive iformatio o the etire power system, expose slow chages, as ca result from a chagig load or geerator structure, ad reveal potetial for eergy savigs. Evet recordig Evet recordig provides iformatio o the time, level ad duratio of limit value violatios ad a classificatio of evets to EN 50160, UNIPEDE, CBEMA or ITIC, for example. It should also be possible for the evet sigatures to be recorded ad displayed graphically if desired. Fast fault recordig Whe a limit value violatio occurs, all aalog ad biary sigals are recorded with a cofigurable resolutio of 100 Hz to 30 khz. The recordig comprises separately cofigurable time widows for pre-fault, fault ad post-fault periods. The fault recordig duratio ca either be set to a fixed legth or ca be cotrolled by the actual duratio of the evet. These recordigs make it possible to carry out comprehesive ad detailed aalyses of power system faults. Slow fault recordig I additio to the aalog ad digital sigals which are measured directly, the RMS recorder ca also record all the quatities calculated o the basis of these sigals, such as frequecy, ubalace, positive sequece system, egative sequece system ad zero sequece system, active power, reactive power ad apparet power, harmoics, etc. The samplig rate ca be set betwee 1 Hz ad double the system frequecy. The recordig is ideal for detectig ad assessig slow processes, such as power swigs, for geerator moitorig or machiery start-ups. Recordig of digital evets ad states Biary iputs are primarily used to read i sigals from protectio relays, circuit breaker positios or machie coditios, for example, which are of decisive importace for the aalysis of fault records. The biary iputs ca also be used to trigger fault records i order to obtai a high-resolutio record of the state of the power system at the momet of switchig. 4
Logical evets Logical liks ca be created with the aalog ad biary measuremet sigals. If coditios cofigured by the user are fulfilled, alarm sigals ca be set via relay outputs or email. To avoid time delays, emails should be set directly by the measurig device itself ad ot by a cetral data server. Usig this fuctio, it is possible to implemet a very flexible moitorig system with the EPPE CX power quality aalyser i cojuctio with the sesor measurig module. The user is iformed immediately if, for example, the module temperature i the case of PV plats, the wid speed i the case of wid power plats or the power cosumptio of machies is exceeded. Eergy meter I additio to measurig power quality, a built-i eergy meter ca also be used to moitor power cosumptio ad optimise cosumptio with the aid of log-term tred aalysis. It should be possible to record ad precisely aalyse active, reactive ad apparet eergy. Depedig o the measuremet task, a detailed 4 quadrat measuremet is required. Software The software desiged for the measurig device should offer a wide variety of possibilities, ragig from the operatio of a idividual measurig device up to the admiistratio of complex groups of measurig devices. As metioed previously, the time available to the user is ofte very limited. For this reaso the software should be geared to meet realworld requiremets ad be easy to operate. The user must be able to carry out a measuremet i accordace with a specific stadard (e.g. EN 50160) without spedig a lot of time gettig used to the software or havig to atted a special traiig course. However, the software should feature the optio of maagig ad cofigurig comprehesive measuremets with complex groups of measurig devices ad should be able to comprehesively aalyse the measuremet results. A umber of tools for aalysig data are provided which simplify the evaluatio. The software developed by KoCoS Messtechik AG is a good solutio for meetig the abovemetioed requiremets. All the versios of the software are very easy to use ad feature a variety of fuctios, icludig the followig: Flexible cofiguratio for optimum adaptatio to a wide rage of measuremet tasks Remote cofiguratio/admiistratio Fully automatic operatio of the measurig system with: Log-distace data trasmissio Archivig of records i a database Pritout or dispatch of fault reports or PQ reports Export i commo PQ ad fault record formats Olie moitorig Import ad export fuctios eable data to be exchaged betwee differet systems usig stadard file formats such as PQDIF, COMTRADE, CSV ad XML (Nequal) Fig. 4: Device maagemet 5
Easy-to-use aalysis tool with automatic evaluatio ad assessmet of power quality to iteratioal stadards (e.g. EN 50160) Multi-scree capability (optimum overview, a wealth of iformatio at a glace) Device maagemet The status iformatio for all the devices coected to the software is displayed i a clearly structured device list, device settigs ca be chaged quickly ad easily. I additio, graphical device maagemet allows measurig devices ad their status iformatio to be displayed i a map or a circuit diagram, for example. This provides the user with a optimum overview of all measuremets, eve i comprehesive moitorig systems. Evaluatio of measuremet data Power systems ad power quality aalysis ca be carried out automatically to the selected stadard (e.g. EN 50160). A umber of aalysis tools are provided for this purpose. The software also icludes a comprehesive rage of powerful aalysis tools for the assessmet of fault records. Examples: Slow chages with tred aalysis Evet recordig with sigature display Flicker aalysis Harmoic aalysis Aalysis of iterharmoics Evet classificatio ad assessmet (UNIPEDE, ITIC, etc.) Graphical display of extreme value duratio distributio Table overview of limit value violatios User-defied limit value ad aalysis settigs Automatic geeratio of weekly, mothly, quarterly ad aual reports Calculatio ad sigal display of differetial curret measuremets Useful zoom fuctios ad variable scalig Superimpositio of differet sigal characteristics Formulary ad editor for the calculatio of further power system quatities Vector displays Idividual report creatio usig the clipboard Automatic report creatio Fig. 5: Tred aalysis 6
Fig. 6: Aalysis of a fault record Coclusios I order to cope with the variety of measuremet tasks faced i practice, moder measurig systems must offer a broad rage of fuctios ad a high degree of flexibility. However, users eed measurig systems which ca be operated easily ad ituitively. They eed to be able to carry out measuremets i accordace with pre-defied stadards (e.g. EN 50160) ad export the measuremet results i a clearly structured form, such as a report, without havig specialist kowledge. At the same time, users with expert kowledge wat to be able to carry out complex measuremets followed by highly detailed aalyses. But eve the best measurig system is useless without user-friedly software which is techically mature. This surely gives visioary maufacturers the edge over the competitio. 7
How reliable is your power supply? twild@kocos.com Dipl.-Ig. Timo Wild MBA Product Maager Fault Recordig & Power Quality, KoCoS Messtechik AG Timo Wild studied electrical egieerig at the Uiversity of Applied Scieces of South-Westphalia ad graduated as a qualified egieer. Sice 2008 he has bee employed as a product maager at KoCoS Messtechik AG with resposibility for fault recorders ad power quality aalysers. While workig full time, he successfully completed his MBA (Master of Busiess Admiistratio) at the Uiversity of Applied Scieces of South-Westphalia. KoCoS Messtechik AG Südrig 42 34497 Korbach, Germay Phoe +49 5631 9596-0 Fax +49 5631 9596-17 ifo@kocos.com www.kocos.com EPPE CX Power quality measuremet Multi-fuctioal measuremet ad aalysis system for comprehesive moitorig of electrical istallatios at all voltage levels. The combiatio of fully automatic, cotiuous measuremets ad easy operatio esures that detailed ad iformative aalysis ca be delivered across a wide rage of applicatios. Sesor measuremet iputs Iovative touch scree Itegrated fault recorder Measuremet to EN 50160 Logical liks Eergy meter IEC 61850 KoCoS Messtechik AG 201501 8