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1	Fault Location of High Voltage Lines with Neural Network Method lin, chia-hung 21 June 2000 (has links) An electric power system consists of the generating stations, the transmission lines, and the distribution systems. Transmission lines are the connecting links between the generating stations and the distribution systems. With the rapid growth of economy and technology, the demand for large blocks of power, power quality and increased reliability suggested the interconnection of neighboring systems. Transmission lines are elements of a network which connects the generating plants to the distribution systems, and could extend hundreds of miles . Because of the long distances traversed by transmission lines over open area, they tend to fade by natural and artificial calamity imposed on the power system. It maybe easy to discover the fault with sufficient information in the populous region. When fault occurs in the remote region, it is difficult to identify the outage location. An efficient and reliable technique is thus desirable to resolve the problem. This dissertation presents the fault location for high voltage lines with Artificial Neural Network( ANN ) method. Beside the fault location, this research also improve the problem further by considering the fault resistance. The fault resistance may not remain the same due to the variation of environmental factors. The fault location may involve errors owing to the fault resistance. An algorithms has been developed in this dissertation to calculate fault resistance and revise the ANN training data for three-phase fault, double line-to-ground fault, single line-to-ground fault, and line-to-line fault. To verify the effectiveness of the method, practical transmission lines were used for tests. The results proved that the method could be used to identify the fault location effectively and help dispatchers determine a reference distance. Artificial Neural Network Fault Location Fault Resistance
2	Relé de distância tipo-fase compensado para sistemas de transmissão Marzec, Denise Pivatto January 2011 (has links) Relés de distância são muito utilizados para proteger linhas de transmissão. Porém, há baixa precisão dos limites de sua zona de proteção devido a fenômenos de subalcance e sobrealcance. Assim, nesta dissertação de mestrado é proposto um algoritmo com compensação da resistência de falta, baseado em coordenadas de fase, objetivando aumentar a precisão dos limites da zona de proteção. A formulação proposta utiliza uma estimativa da corrente de falta para estimar a resistência de falta e compensar a impedância aparente calculada. Foram realizados o equacionamento e desenvolvimento do algoritmo para faltas tipo fase. Simulações e testes numéricos comparativos com formulações estado-da-arte verificaram a eficiência do método proposto. / Distance Relays are widely used to protect transmission lines. However, due to underreaching and overreaching phenomena, there is a low precision in protection zone limits of distance relays. Thus, in this dissertation, a new algorithm based in phase coordinates is proposed to increase the precision in zone protection limits. The proposed method uses the fault corrent to estimate the fault resistance and compensate the apparent impedance calculated. The equation development was done for phase type faults. Comparative tests with state-of-the-art formulations verified the efficiency of the proposed method. Linhas de transmissão Análise de falhas Distance relaying Power system protection Fault resistance Protection zone
3	Relé de distância tipo-fase compensado para sistemas de transmissão Marzec, Denise Pivatto January 2011 (has links) Relés de distância são muito utilizados para proteger linhas de transmissão. Porém, há baixa precisão dos limites de sua zona de proteção devido a fenômenos de subalcance e sobrealcance. Assim, nesta dissertação de mestrado é proposto um algoritmo com compensação da resistência de falta, baseado em coordenadas de fase, objetivando aumentar a precisão dos limites da zona de proteção. A formulação proposta utiliza uma estimativa da corrente de falta para estimar a resistência de falta e compensar a impedância aparente calculada. Foram realizados o equacionamento e desenvolvimento do algoritmo para faltas tipo fase. Simulações e testes numéricos comparativos com formulações estado-da-arte verificaram a eficiência do método proposto. / Distance Relays are widely used to protect transmission lines. However, due to underreaching and overreaching phenomena, there is a low precision in protection zone limits of distance relays. Thus, in this dissertation, a new algorithm based in phase coordinates is proposed to increase the precision in zone protection limits. The proposed method uses the fault corrent to estimate the fault resistance and compensate the apparent impedance calculated. The equation development was done for phase type faults. Comparative tests with state-of-the-art formulations verified the efficiency of the proposed method. Linhas de transmissão Análise de falhas Distance relaying Power system protection Fault resistance Protection zone
4	Relé de distância tipo-fase compensado para sistemas de transmissão Marzec, Denise Pivatto January 2011 (has links) Relés de distância são muito utilizados para proteger linhas de transmissão. Porém, há baixa precisão dos limites de sua zona de proteção devido a fenômenos de subalcance e sobrealcance. Assim, nesta dissertação de mestrado é proposto um algoritmo com compensação da resistência de falta, baseado em coordenadas de fase, objetivando aumentar a precisão dos limites da zona de proteção. A formulação proposta utiliza uma estimativa da corrente de falta para estimar a resistência de falta e compensar a impedância aparente calculada. Foram realizados o equacionamento e desenvolvimento do algoritmo para faltas tipo fase. Simulações e testes numéricos comparativos com formulações estado-da-arte verificaram a eficiência do método proposto. / Distance Relays are widely used to protect transmission lines. However, due to underreaching and overreaching phenomena, there is a low precision in protection zone limits of distance relays. Thus, in this dissertation, a new algorithm based in phase coordinates is proposed to increase the precision in zone protection limits. The proposed method uses the fault corrent to estimate the fault resistance and compensate the apparent impedance calculated. The equation development was done for phase type faults. Comparative tests with state-of-the-art formulations verified the efficiency of the proposed method. Linhas de transmissão Análise de falhas Distance relaying Power system protection Fault resistance Protection zone
5	Výpočet nastavení distančních ochran v síti 110 kV / The calculation of 110 kV network distance protection relays setings. Bartoš, Petr January 2012 (has links) This master’s thesis is about setting of distance protections. The first part is focused on a brief analysis of the basic types of failures and distance protections tripping characteristics and their co-operation with automatic re-turn. The most extensive theoretical chapter is devoted to specific influences that negatively affect the proper operation of distance protections. The practical part is about calculation of symmetrical short-circuit and dissymmetrical short-circuit conditions with consideration of fault resistance and the actual calculation settings of distance protections. Calculations of short-circuit conditions and setting of distance protections are made on a specific part of the network of E.ON in area Prostejov, which is supplied from the substation 400/110 kV Otrokovice.
6	Indikace zemních spojení na venkovních vedeních / The Indication of Earth Faults in Overhead Lines Pospíšil, Zdeněk January 2015 (has links) This master´s thesis deals with the indication and localization of earth faults in overhead lines. Earth fault is the most frequently occurring type of fault in medium voltage overhead lines – it covers approx. 95% of all faults and is very difficult to indicate and localize them correctly and in time with currently available methods on the market. Therefore is very important to study earth fault and its indication, localization. The thesis consists of a theoretical and a practical part. The theoretical part deals with faults in overhead networks with different type of neutral grounding, mainly with one phase to the ground fault in the compensated, ungrounded, solidly grounded and via resistance grounded networks. Most of the theoretical part is dedicated to one phase to the ground fault in the compensated and ungrounded networks, where this type fault is called the earth fault. In the compensated and ungrounded networks is described in details behavior – voltage and current relations during both steady state and transient state earth fault. The theoretical part is further dedicated to detection methods of earth faults and their preconditions for use. There is described also in details the complete procedure of earth fault detection, which includes indication, unhealthy feeder determination and exact position or line section localization. End of the theoretical part is then focused on determination of accuracy requirements for measurement of basic quantities and computation of other parameters. The practical part deals with a work at medium distribution network model, which includes familiarization with the model, detailed verification of its functionality and behavior during the earth fault, obtaining faults records and algorithmization of methods: method of qu – diagram and method of first half - period, which are able to detect unhealthy feeder. This part of the thesis was put together based on a demand of company Mega, corp., which wanted to verify function of both above mentioned and by them not yet tested methods.
7	Fault Location Algorithms in Transmission Grids Harrysson, Mattias January 2014 (has links) The rapid growth of the electric power system has in recent decades resulted in an increase of the number of transmission lines and total power outage in Norway. The challenge of a fast growing electrical grid has also resulted in huge increases of overhead lines and their total length. These lines are experiencing faults due to various reasons that cause major disruptions and operating costs of the transmission system operator (TSO). Thus, it’s important that the location of faults is either known or can be estimated with reasonably high accuracy. This allows the grid owner to save money and time for inspection and repair, as well as to provide a better service due to the possibility of faster restoration of power supply and avoiding blackouts. Fault detection and classification on transmission lines are important tasks in order to protect the electrical power system. In recent years, the power system has become more complicated under competitive and deregulated environments and a fast fault location technique is needed to maintain security and supply in the grid. This thesis compares and evaluates different methods for classification of fault type and calculation of conventional one-side and two-side based fault location algorithms for distance to fault estimation. Different algorithm has been implemented, tested and verified to create a greater understanding of determinants facts that affect distance to faults algorithm’s accuracy. Implemented algorithm has been tested on the data generated from a number of simulations in Simulink for a verification process in implemented algorithms accuracy. Two types of fault cases have also been simulated and compared for known distance to fault estimation. electric power system transmission lines Smart Grid fault detection fault location techniques disruptions caused by storms transmission fault calculation of distance to fault Statnett one-side algorithms two-side algorithms fault types fault location methods one-ended fault location algorithm reactance based algorithm takagi method fault location algorithms by saha Harrysson two-ended fault location estimation fault resistance Avstånd till fel ABB Statnett Matlab Simulink Transmissions nätet Avstånds till fel algorithmer Fel lokalisering

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