Att hitta fel, att kunna lokalisera och identifiera kablar i mark är en aktuell fråga då allt mer friledning ersätts med markförlagd kabel. Att snabbt lokalisera och reparera ett fel sparar pengar för energibolagen och minskar den tid kunderna är utan elförsörjning. Dagens skyddsutrustning har integrerade fellokalisering inbyggd, detta ger dock endast en ungefärlig bild av var fel finns. Mer exakt lokalisering sker med en förlokalisering, nu förtiden används pulsekometoden. En puls skickas ut på den skadade ledaren och en oskadad ledare, pulsen reflekteras i felstället och i kabelendan. Tiden från det pulserna lämnar pulsgeneratorn tills de återvänder jämförs. Detta ger avståndet till felet i meter. Där efter så används en av två efterlokaliseringsmetoder. Stötspänningsaggregat med en markmikrofon, aggregatet genererar ett överslag i felstället, urladdningen kan lokaliseras med hjälp av markmikrofonen. Andra metoden är tongenerator och en sökstav. Tongeneratorn skickar ut en högfrekvent puls på den trasiga ledaren, detta genererar ett magnetfält som kan följas med hjälp av sökstaven. När signalen försvinner så har felet lokaliserats. Kursen Elförfattning och Elinstallation (ELI 200) på Högskolan Väst saknar ett praktiskt övningstillfälle för kabellokalisering, kabelfelsökning och kabelidentifiering. Uppgiften var att ta fram en laboration, där en eller flera mätningar utförs på olika kablar i mark. Laborationen skall ingå som ett obligatoriskt moment i kursen. Målet var att laborationen skulle återspegla en verklig kabellokalisering och en kabelidentifiering. Geografiskt kommer laborationen att utföras på Magnus Åbergsgymnasiets laborationsområde i Trollhättan. Metoder att genomföra examenarbetet bestod av faktainsamling via litteratur och rapporter. Laborationsplatsen var redan förutbestämd. Kontakt med personal ifrån Magnus Åbergsgymnasiet etablerades, laborationen utformades och testades av gruppen samt oberoende part för att upptäcka eventuella brister och för att se att instruktionerna var tydliga. Ett facit med svar och referensvärden utformades och förslag på lärarhandledning skapades. På grund av begränsad tillgång av mätinstrument och av praktisk anledning begränsades laborationen till ett moment med kabellokalisering med hjälp av söksond och ett moment med kabelidentifiering. / Be able to quickly locate and identify a faulty cable and repair it is quite necessary these days, since most power-line this days are buried and power-shortages cost the energy companies a lot of money and are very irritating to the customers. Modern system are integrated whit pre-localizations equipment, the precision is not grate. To locate the problem a method of eco-localizations are deployed, a pulse in sent threw the faulty line and also threw a functional line. The pulse reflects in the fault and in the end of the line, the time deferens results in distends to the faults location. To achieve a more exact position there are two methods in use. A shock-voltage-generator produce an audible detonation in the faults location, the detonations can then be located whit a ground-microphone. The other method in use is a frequency-generator that produces a magnetic-field around the cable. The field can then be traced whit a locator-staff. When the signal disperse the approximate location of the fault is located. The course Electrical ordinance and Electrical installation lacks an applied training session regarding cable fault detection and cable identifying. The task was to develop a laboratory experiment in which one or more cables are identified and located. The lab would be included as a compulsory part of the course. The goal was that the lab would reflect a real work situation including pre-localizing, precise- localizing and in case of multiple cables, a moment of identifying the specific cable. The geographic location for the training session is pre-determined and are placed at Magnus Åbergs high school outdoor practice area in Trollhättan. Methods to carry out the thesis work consisted of gathering facts through literature, reports. The lab was designed and tested to detect any flaws. An answer key of reference values was designed and suggestions for a teacher's guide were created. The delimitations where the access to measuring instruments and fore practical reasons the advisors from University West and the representative from Magnus Åbergs high school decided to limit the training session to cable localization and cable identifying.

Dala Energi Elnät is a smaller grid company with network operations consisting of the distri-bution and measurement of electricity. The company is interested in acquiring greater know-ledge of the error detection equipment that can in a early stage detect errors in the medium-voltage network. Which hopefully results in faster fault location and cost savings for the company.The purpose of this study is to investigate the fault-detection equipment that would fit into the Dala Energys medium voltage grid and what experiences others electricity companies have with fault-detection equipment. Fault detection equipment used in the study has been limited to equipment from the companies Protrol AB and dLaboratory AB. Structure and function of the equipment are investigated and empirical experience obtained through a telephone interview and a visit on the electricity network companies Kraftringen respectively Falu Elnät AB.Protrols fault-detection equipment consists of error detectors that measure only the current for detecting ground faults and over currents and mainly used in substations. Communication to the control center can be made by fiber, Ethernet or signal cable. The simplest detectors have no communication link without signals with LED indicator on the substation if the fault current passed. Configuration, settings, and registered error events must be downloaded by USB connection on site.dLaboratorys concept is that the industrial PC installed in a distribution substation, where the current and voltage are measured in each output tray, to detect ground faults and overcurrents. Relay Protection functions are available on the PC, which means that both fault detection and protection equipment available. Information from the measurements sent to dLaboratorys serves for analysis and transmitted to power grid owner. On dLaboratorys website the information can then be reviewed with a convenient interface.Selection of fault-detection equipment is affected by electricity network design with radial or meshed networks, existing grid equipment, relay protection, geographical distance and communication facilities etc. Where a comprehensive solution from a longer term perspective should be taken into account. Recording options in error-detection equipment can be used to better understand the reasons why a protection relay trips, where the events before and after the fault can be analyzed. A financial investment in fault-detection equipment do not always pay for itself, but also provides greater customer benefits and opportunities to identify weak points in the grid. Benefiting from successful experience of other grid companies have had with fault-detection equipment.For the fault-detection equipment included in the study, recommended Protrols equipment to be used on radial parts of the network, where the error detectors are not placed in each substation but strategically where geographical distances are great to reduce troubleshooting time substantially.dLaboratorys fault detection equipment is best suited to distribution stations with many exhausting tray and where it is possible that if sectioning out the fault with remote-controlled switch or circuit breaker. dLaboratory relay protection has worked well in conducted tests on the other hand it remains to be seen how it manages in normal operation. / <p>Validerat; 20160617 (global_studentproject_submitter)</p>

I samband med att mellanspänningsnätet kablifieras ökar också kraven vad gäller fellokalisering. För att hålla avbrottstiderna i nätet korta är effektiv felsökning erforderlig. Detta arbete syftar till att kartlägga och redogöra för begränsande faktorer som finns vid fellokalisering med fokus på pulsekometoden. Uppdraget utförs tillsammans med Vattenfall Eldistribution AB. Det har uppdagats problem gällande fellokalisering på mellanspänningskablar med pulsekometoden. Ett flertal faktorer bidrar till denna problematik. Resultatet från studien visar att kabelkonstruktionen är en betydande del i det som begränsar pulsekometodens användningsområden och funktionalitet. Rapporten redogör för grundläggande information kring konstruktion och typer av mellanspänningskablar. Kartläggningen uppvisar hur vattenträd påverkar en kabel negativt. Allmänt redogörs för vad som orsakar vattenträd samt vilka avhjälpande åtgärder som vidtas; trippelextrudering samt mantel- och isolationsprovning. Vidare beskrivs olika feltyper, kabeltyper, kabelgenerationer samt instrument- och metodtyper som alla är påverkande faktorer vid fellokalisering. Dokumentering är i högsta grad väsentligt för en lyckad felsökningsprocedur, vilket klarläggs i rapporten. Utöver dokumentation redogörs för hur kabelns kondition kan påverka felsökningsresultatet. Ett antal mätmetoder och mätinstrument finns till förfogande vid felsökning och provning. Alla har sina egna för- respektive nackdelar. De har även tillhörande användningsområden. Pulsekometerns grundfunktion studeras och förklaras. De övriga mätmetoderna, som används vid fellokalisering och provning, redogörs för endast generellt / As the medium voltage network cables in Sweden is buried down in the earth, the demand of fault localization expertise increases. To keep downtimes in the network short, the importance of effective fault localization is necessary. This work is aimed to map and visualize limiting factors within fault localization with focus on the TDR - Time Domain Reflectometry. This work is a collaboration with Vattenfall Eldistribution AB. Problems with fault localization on medium voltage cables with the TDR have been detected. A multiple factors are contributing to this problem. The results of this study show that the cable construction is a significant part in which extent the TDR can be used. The report are also accounting for basic information about construction and types. The mapping also illustrates water treeing and how it affects cables in a negative way. Visualization of what causes water treeing and several actions such as triple extrusion, jacket testing and insulation testing is included in the essay. Further information about fault types, cable types, cable generations, instrument types and method types is given. All of them are affecting factors within the area of fault localization. Documentation is highly important for a successful fault localization procedure, which is clarified in the report. Besides documentation the cable condition and the influence on it affecting the result of fault localization is stated. A number of measuring methods and instruments are available to use when fault localization and testing are occurring. Every instrument has their own advantages and disadvantages. They also have their own respective area of usage. The basic principle of TDR is studied and explained accordingly. The other measuring methods, which are used in fault localization and testing, are shown more generally

This paper addresses the question formulation “Is it possible to implement automated testing in an existing client-server game in order to pinpoint faults and achieve credibility to tests?” The gaming industry’s goal, in most cases, is to release games that appeal to both their financial goals and the enjoyment factor of the players. In order to fulfill these goals, the game will need to function properly and the process to assure this is testing the game to find possible faults. This process is time and cost consuming in an exponential rate in accordance to game extensiveness, which makes this problem a very important decision in the process of development. The problem is most commonly tackled by using massive manual testing session, called alpha or beta sessions. In these session the game is at an early stage of development and gets released to a set player base to test and report issues encountered. We believe that the process of testing games could be more effective by utilizing automated testing. This thesis will investigate the possibilities to our claim. The result is a visual representation of the tests we managed to apply, while focusing on the client-server connectivity of Quake 3 and a graph of measurements for our improvised fault localization. This paper describes a solution in form of automated tests within a existing client-server game and a start to what could be early stages of a pattern obtained throughout this project.

With the rapid development of power systems, locating and classifying faults is critical to the continuity and reliability of the transmission system. In this thesis, a traveling-wave based technique for fault location and classification on high voltage and extremely high-voltage transmission lines is proposed. The traveling-wave based protection has the advantage of fast response and not being affected by power swing and CTs saturation. In this thesis, the transient characteristics of single line to ground fault (which can be divided into solid fault and arcing fault) and lightning disturbance are extracted by using Clarke transformation and wavelet transformation. The differences among recorded traveling wave arrival times are used to calculate the fault location, and the wavelet energy at different frequency bands is utilized to distinguish between lightning and different kinds of fault. A criterion is proposed according to the energy ratio. The proposed scheme can identify different faults correctly and quickly. In addition, the influence of busbar capacitance, current transformer and coupling capacitor voltage transformer are considered. The simulation of a transmission system has been made in ATP/EMTP, and the calculations have been made in MATLAB. / Med den snabba utvecklingen av kraftsystem är lokalisering och klassificering av fel avgörande för kontinuiteten och tillförlitligheten hos överföringssystem. I denna avhandling föreslås en vågrörelse-baserad teknik för fellokalisering och klassificering av kraftledningar för högspänning och extremt hög spänning. Vågrörelsebaserat skydd har fördelen av snabb respons och att det inte påverkas av kraft fluktuationer och strömtransformsmättnad. I denna avhandling tas momentana egenskaperna av jord till ledningsfel (vilket kan delas in i stumt jordfel och ljusbågefel) och blixtstörning fram med hjälp av Clarke transformation och wavelet transformation. Skillnaderna mellan de uppmätta vågrörelsernas ankomsttider används för att beräkna fellokalisering och wavelet energin vid olika frekvensband, vilket används för att skilja mellan blixt och olika sorters fel. Ett kriterium föreslås enligt energiförhållandet. Det föreslagna systemet kan identifiera olika sorters fel korrekt och snabbt. Dessutom övervägs påverkan av strömskenans kapacitans, strömtransformator och kopplingskondensatorspänningsomvandlare. Simuleringen av transmissionssystem har gjorts med ATP/EMTP, och beräkningarna är gjorda med MATLAB.