Synchrophasor technology is widely available embedded in modern power grid protection, metering, and recording devices. Utilizing synchrophasor measurements, a novel algorithm is proposed for fault location in multi-terminal transmission lines. In order to implement real-time synchrophasor applications, a software platform called “PhasorEye” was developed in this research. PhasorEye facilitates collecting synchrophasor data stream, visualization of decoded data, and implementation of synchrophasor applications as analysis tools. A laboratory setup involving a RTDS real-time digital simulator and a synchrophasor communication network was assembled to demonstrate and validate the use of the software and the proposed new fault location technique. Tests revealed several challenges in practical application of synchrophasor data for fault location and showed that the proposed fault location algorithm can accurately identify the faulted line segment and fault location. Additionally, several other synchrophasor applications developed by other University of Manitoba researchers were implemented and integrated into the software. / February 2017

<p>In this bachelor thesis, cable fault locators are studied for use on the overhead electrode lines in the HVDC (High Voltage Direct Current) Light project Caprivi Link. The cable fault locators studied operates with the principle of travelling waves, where a pulse is sent in the tested conductor. The time difference is measured from the injection moment to the reflection is received. If the propagation speed of the pulse is known the distance to the fault can be calculated. This type of unit is typically referred to as a TDR (Time Domain Reflectometer). The study is performed as a computer simulation where a simplified model of a TDR unit is created and applied to an electrode line model by using PSCAD/EMTDC. Staged faults of open circuit and ground fault types are placed at three distances on the electrode line model, different parameters of the TDR units such as pulse width and pulse amplitude along with its connection to the electrode line are then studied and evaluated. The results of the simulations show that it is possible to detect faults of both open circuit and ground fault types with a suitable TDR unit. Ground faults with high resistance occurring at long distances can be hard to detect due to low reflection amplitudes from the injections. This problem can somewhat be resolved with a function that lets the user compare an old trace of a “healthy” line with the new trace. The study shows that most of the faults can be detected and a distance to the fault can be calculated within an accuracy of ± 250 m. The pulse width of the TDR needs to be at least 10 μs, preferable 20 μs to deliver high enough energy to the fault to create a detectable reflection. The pulse amplitude seams to be of less significance in this simulation, although higher pulse amplitude is likely to be more suitable in a real measurement due to the higher energy delivered to the fault. The Hipotronics TDR 1150 is a unit that fulfil these requirements and should therefore be able to work as a line fault locator on the electrode line.</p>

Transmission lines of any voltage level are subject to faults. To speed up repairs and restoration of power, it is important to know where the fault is located. A fault location algorithm’s result is influenced by a series of modeling equations, setting parameters and system factors reflected in voltage and current inputs. The factors mentioned are subject to sources of uncertainty including measurement and signal processing errors, setting errors and incomplete modeling of a system under fault conditions. These errors have affected the accuracy of the distance to fault calculation. Accurate fault location reduces operating costs by avoiding lengthy and expensive patrols. Accurate fault location speeds up repairs and restoration of lines, ultimately reducing revenue loss caused by outages. In this thesis, we have reviewed the fault location algorithms and also how the uncertainty affects the results of fault location. Sensitivity analysis is able to analyze how the variation in the output of the fault location algorithms can be allocated to the variation of uncertain factors. In this research, we have used global sensitivity analysis to determine the most contributed uncertain factors and also the interaction of the uncertain factors. We have chosen Analysis of Variance (ANOVA) decomposition as our global sensitivity analysis. ANOVA decomposition shows us the insight of the fault location, such as relations between uncertain factors of the fault location. Quasi regression technique has also been used to approximate a function. In this research, the transmission line fault location system is fitted into the ANOVA decomposition using quasi regression. From the approximate function, we are able to get the variance of the sensitivity of fault location to uncertain factors using Monte Carlo method. In this research, we have designed novel methodology to test the fault location algorithms and compare the fault location algorithms. In practice, such analysis not only helps in selecting the optimal locator for a specific application, it also helps in the calibration process. / Thesis (M.Eng.Sc.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2009

Society is increasingly concerned about the environmental impact of energy systems, and prefers to locate power lines underground. In future, certain socially/environmentally sensitive overhead transmission feeders will need to include underground cable sections. Fault location, especially when using travelling waves, become complicated when the combined transmission line includes a number of discontinuities, such as junction points, teed points and fault points. Consequently, a diverse range of fault locators were developed in this thesis, and the performance of the proposed fault locators investigated. For a combined transmission line (CTL), consisting of one or more overhead line sections and one or more underground cable sections, a hybrid fault location scheme is proposed. This utilises the robustness of an impedance based distance algorithm and the accuracy, but stability concerns, of a travelling wave based fault locator, to determine the faulted section. The distance algorithm can determine the approximate fault location, but if the fault is located near an “underground-overhead” junction point, the accuracy is not sufficient to decide whether the fault is located on the overhead or the underground section. This thesis proposes utilizing a single end travelling wave fault locator to improve the accuracy of the fault location decision. The single end travelling wave fault locator can determine the fault section according to the permutation of the polarity of the “special surges”, which is especially important when the fault is close to a junction point. However, this single end fault locator fails in certain “blind” areas, wand these require the use of a distance relay to help determine fault section. Simulation results demonstrated that this hybrid fault locator can reliably determine which section of the feeder is faulty. For all types of CTL, including teed networks, the multiple-end travelling wave fault locator, utilising the arrival time at the feeder ends of the first fault instigated surges, can estimate the fault location. One of the main features of the proposed fault locator is the classification of the time difference between the arrivals of a fault instigated surge at the feeder ends as standard values, when the fault is located at each of the junction points or teed points. Comparing the time differences measured during an actual fault with these standard values allows the faulted feeder section to be estimated. The simulation results show this multiple-end travelling wave fault locator is highly reliable and suitable for application on combined overhead and underground transmission lines.

This thesis gives an overview on the fault of high-voltage cable transmission lines in the distribution system of the E.ON company. The first part of this thesis introduces reader to the topic of cable transmission lines, types of commonly used cables and the most commonly occurring faults. In the second part of this thesis, the methods of locating faults in cable transmission lines by professional personnel are explained. The third part deals with the analysis of a group of chosen occurred faults. The final part focuses on the statistics of fault occurrence on South Moravian region from 1.1.2017 until 1.1.2019.

In this bachelor thesis, cable fault locators are studied for use on the overhead electrode lines in the HVDC (High Voltage Direct Current) Light project Caprivi Link. The cable fault locators studied operates with the principle of travelling waves, where a pulse is sent in the tested conductor. The time difference is measured from the injection moment to the reflection is received. If the propagation speed of the pulse is known the distance to the fault can be calculated. This type of unit is typically referred to as a TDR (Time Domain Reflectometer). The study is performed as a computer simulation where a simplified model of a TDR unit is created and applied to an electrode line model by using PSCAD/EMTDC. Staged faults of open circuit and ground fault types are placed at three distances on the electrode line model, different parameters of the TDR units such as pulse width and pulse amplitude along with its connection to the electrode line are then studied and evaluated. The results of the simulations show that it is possible to detect faults of both open circuit and ground fault types with a suitable TDR unit. Ground faults with high resistance occurring at long distances can be hard to detect due to low reflection amplitudes from the injections. This problem can somewhat be resolved with a function that lets the user compare an old trace of a “healthy” line with the new trace. The study shows that most of the faults can be detected and a distance to the fault can be calculated within an accuracy of ± 250 m. The pulse width of the TDR needs to be at least 10 μs, preferable 20 μs to deliver high enough energy to the fault to create a detectable reflection. The pulse amplitude seams to be of less significance in this simulation, although higher pulse amplitude is likely to be more suitable in a real measurement due to the higher energy delivered to the fault. The Hipotronics TDR 1150 is a unit that fulfil these requirements and should therefore be able to work as a line fault locator on the electrode line.

Orientador: Jose Sanches Mantovani / Resumo: Neste trabalho propõe-se um método para a localização de faltas que, em conjunto com a lógica de um relé diferencial numérico, deve ser usado para proteção de linhas de transmissão com compensação série controlada por tiristores (TCSC). Este método visa solucionar o problema de localização de faltas melhorando a precisão dos algoritmos que utilizam medições de sinais de tensão e corrente numa terminação da linha de transmissão. O cálculo da distância entre a terminação da linha de transmissão e o ponto de incidência da falta é realizado utilizando dois procedimentos: um para faltas produzida no trecho entre a terminação local da linha de transmissão e o TCSC; e o outro para faltas no trecho entre o TCSC e a terminação remota. A detecção do trecho de incidência da falta é obtido usando as medições de escorregamento angular dos sinais de corrente em ambos os extremos da linha de transmissão e a medição da resistência de falta no extremo local, que é variável durante o intervalo de início até um ciclo depois da ocorrência da falta. A aplicação da lógica difusa na comparação destas medições permite detectar com precisão o trecho com falta. O método proposto foi testado usando um sistema teste da literatura onde múltiplos casos de faltas em diferentes pontos da linha de transmissão foram simulados. Os resultados mostram a capacidade do algoritmo em localizar precisamente a posição de ocorrência da falta. / Abstract: This paper proposes a methodology for locating faults in transmission lines with thyristor-controlled series compensation (TCSC) that are protected by numerical differential relays. The proposed methodology aims to overcome problems of fault location improving the accuracy of algorithms that use voltage and current measurement signals from a transmission line termination. The calculation of the distance between the transmission line termination and the fault incidence point employs two procedures: one for faults in the transmission line section limited by the local termination and TCSC; and other for faults in the section limited by the TCSC and remote termination. The detection of the fault incidence section is achieved using measurements of angular deviation for both transmission line terminations and the measurement of fault resistance in the local termination, which varies during the interval from the beginning to one cycle after the fault occurrence. The use of fuzzy logic for comparing these measurements permits the accurate detection of the fault incidence section. The proposed method is tested using a test system from literature system where multiple fault cases in different positions of the transmission line are simulated. The results show the algorithm capability to locate accurately the position of fault occurrence. / Mestre

Submitted by NELSON GIOVANNY ROMERO TAQUIRE (romero.taquire.nelson@gmail.com) on 2016-05-20T21:35:24Z No. of bitstreams: 1 NelsonGiovannyRomeroTaquire2016.pdf: 3534022 bytes, checksum: 59ecb7956af007830fd18b15c10562c2 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-24T13:42:19Z (GMT) No. of bitstreams: 1 taquire_ngr_me_ilha.pdf: 3534022 bytes, checksum: 59ecb7956af007830fd18b15c10562c2 (MD5) / Made available in DSpace on 2016-05-24T13:42:19Z (GMT). No. of bitstreams: 1 taquire_ngr_me_ilha.pdf: 3534022 bytes, checksum: 59ecb7956af007830fd18b15c10562c2 (MD5) Previous issue date: 2016-03-21 / Fundação de Ensino, Pesquisa e Extensão de Ilha Solteira (FEPISA) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho propõe-se um método para a localização de faltas que, em conjunto com a lógica de um relé diferencial numérico, deve ser usado para proteção de linhas de transmissão com compensação série controlada por tiristores (TCSC). Este método visa solucionar o problema de localização de faltas melhorando a precisão dos algoritmos que utilizam medições de sinais de tensão e corrente numa terminação da linha de transmissão. O cálculo da distância entre a terminação da linha de transmissão e o ponto de incidência da falta é realizado utilizando dois procedimentos: um para faltas produzida no trecho entre a terminação local da linha de transmissão e o TCSC; e o outro para faltas no trecho entre o TCSC e a terminação remota. A detecção do trecho de incidência da falta é obtido usando as medições de escorregamento angular dos sinais de corrente em ambos os extremos da linha de transmissão e a medição da resistência de falta no extremo local, que é variável durante o intervalo de início até um ciclo depois da ocorrência da falta. A aplicação da lógica difusa na comparação destas medições permite detectar com precisão o trecho com falta. O método proposto foi testado usando um sistema teste da literatura onde múltiplos casos de faltas em diferentes pontos da linha de transmissão foram simulados. Os resultados mostram a capacidade do algoritmo em localizar precisamente a posição de ocorrência da falta. / This paper proposes a methodology for locating faults in transmission lines with thyristor-controlled series compensation (TCSC) that are protected by numerical differential relays. The proposed methodology aims to overcome problems of fault location improving the accuracy of algorithms that use voltage and current measurement signals from a transmission line termination. The calculation of the distance between the transmission line termination and the fault incidence point employs two procedures: one for faults in the transmission line section limited by the local termination and TCSC; and other for faults in the section limited by the TCSC and remote termination. The detection of the fault incidence section is achieved using measurements of angular deviation for both transmission line terminations and the measurement of fault resistance in the local termination, which varies during the interval from the beginning to one cycle after the fault occurrence. The use of fuzzy logic for comparing these measurements permits the accurate detection of the fault incidence section. The proposed method is tested using a test system from literature system where multiple fault cases in different positions of the transmission line are simulated. The results show the algorithm capability to locate accurately the position of fault occurrence.

This thesis describes an investigation into the influences of arcing and conductor deflection due to magnetic forces on the accuracy of fault locator algorithms in electrical distribution networks. The work also explores the possibilities of using the properties of an arc to identify two specific types of faults that may occur on an overhead distribution line. A new technique using the convolution operator is introduced for deriving differential equation algorithms. The first algorithm was derived by estimating the voltage as an array of impulse functions while the second algorithm was derived using a piecewise linear voltage signal. These algorithms were tested on a simulated single-phase circuit using a PI-model line. It was shown that the second algorithm gave identical results as the existing dynamic integration operator type algorithm. The first algorithm used a transformation to a three-phase circuit that did not require any matrix calculations as an equivalent sequence component circuit is utilised for a single-phase to ground fault. A simulated arc was used to test the influence of the non-linearity of an arc on the accuracy of this algorithm. The simulations showed that the variation in the resistance due to arcing causes large oscillations of the algorithm output and a 40th order mean filter was used to increase the accuracy and stability of the algorithm. The same tests were performed on a previously developed fault locator algorithm that includes a square-wave power frequency proximation of the fault arc. This algorithm gave more accurate and stable results even with large arc length variations. During phase-to-phase fault conditions, two opposing magnetic fields force the conductors outwards away from each other and this movement causes a change in the total inductance of the line. A three dimensional finite element line model based on standard wave equations but incorporating magnetic forces was used to evaluate this phenomenon. The results show that appreciable errors in the distance estimations can be expected especially on poorly tensioned di stribution lines.New techniques were also explored that are based on identification of the fault arc. Two methods were successfully tested on simulated networks to identify a breakingconductor. The methods are based on the rate of increase in arc length during the breaking of the conductor. The first method uses arc voltage increase as the basis of the detection while the second method make use of the increase in the non-linearity of the network resistance to identify a breaking conductor. An unsuccessful attempt was made to identifying conductor clashing caused by high winds: it was found that too many parameters influence the separation speed of the two conductors. No unique characteristic could be found to identify the conductor clashing using the speed of conductor separation. The existing algorithm was also used to estimate the voltage in a distribution network during a fault for power quality monitoring purposes.

This master’s thesis is about earth fault locator testing on the model of unsymmetrical lines. The introductory part of thesis describes the function of the selected locator, mainly for the used calculation algorithm of fault location, options setting of fault locator and connection of the locator to the network. Master’s thesis in its practical part deals, with the setting fault locator for a particular test system on the model of the MV line and implementation of selected testing on the model unsymmetrical lines. The first part of the testing is focusing on verify the accuracy locator on an unsymmetrical line. The second test is then designed for obtaining the most accurate information on the distance of the fault, which fault locator can give. The final part is focused on verification algorithm for more accurate calculation of the fault location.