Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-09T19:03:09Z No. of bitstreams: 1 107110001.pdf: 3453553 bytes, checksum: fb266cf11dce80833ef41b2adb20cd21 (MD5) / Made available in DSpace on 2015-05-09T19:03:09Z (GMT). No. of bitstreams: 1 107110001.pdf: 3453553 bytes, checksum: fb266cf11dce80833ef41b2adb20cd21 (MD5) Previous issue date: 2012-10-19 / As distribuidoras de energia elétrica devem estar preparadas para restabelecer o fornecimento de forma ágil, sempre respeitando os critérios de segurança e os índices de continuidade e qualidade compatíveis com o estabelecido na legislação vigente. A possibilidade de localizar defeitos remotamente acelera o processo de restabelecimento. Apesar dos próprios relés e religadores microprocessados fornecerem uma indicação com base na impedância de curto-circuito, ela não é precisa para sistemas de distribuição, uma vez que as redes apresentam várias bifurcações (ramais) protegidas por elementos fusíveis e diferentes bitolas de condutores. Entretanto, atualmente há vários métodos como revelam as pesquisas, que tentam estabelecer maior precisão dos dados e resultados ali envolvidos, buscando criar uma inovação e satisfação às empresas do setor elétrico. Assim, a proposta deste projeto é desenvolver uma metodologia diferencial para localização de faltas em redes de distribuição a partir de estudos da rede combinados com a monitoração remota de dispositivos de proteção (relés e religadores microprocessados). Estas variáveis de entrada: corrente de carga (corrente pré-falta), corrente de curto-circuito, corrente pós-falta; serão obtidas em tempo real pelo SCADA no momento da ocorrência de uma falta na rede. As medidas obtidas serão comparadas e classificadas por Mapas Auto-Organizáveis ou SOM (Self-Organizing Map) de acordo com os padrões de dados simulados pelos estudos da rede. A partir do método proposto será possível estimar o local do defeito ocorrido na rede elétrica por meio do mapa que melhor se identifica com os dados medidos. Essa pesquisa foi aplicada no estudo de caso de uma concessionária da região central gaúcha, a qual alcançou resultados bastante satisfatórios, obtidos a partir de dados reais. / The power utilities must be prepared to restore the supply in an agile way constantly respecting the safety criteria and indexes of continuity and quality consistent with the current legislation. The ability to remotely locate defects accelerates this healing process. Despite own microprocessor relays and reclosers provide an indication based on the short circuit impedance, it is not applicable to distribution systems, since the networks present various bifurcations (branch lines) protected by fuse elements and different wire gauges. However, today there are several methods such as surveys show, trying to establish more precisely the data and results here involved, seeking to create an innovation and satisfaction to the electric companies. Thus, the aim of this project is to develop a methodology for distinct fault location in distribution feeders. It will combine network studies with remote monitoring of protective devices (microprocessor relays and reclosers). These input variables: load current (pre-fault current), short circuit current, post-fault current; will be obtained in real time by SCADA when a fault occurs in the network. These measures will be compared and ranked by Self- Organizing Maps (SOM) according to the patterns obtained by simulation studies of the network. With this method, it will be possible to assess the location of the defect occurring in the power grid, identifying the best map that resembles with the measured data. This research was applied in a power utility in the South of Brazil as case study, which achieved satisfactory results obtained from real data.

Orientador: Jônatas Boás Leite / Resumo: A análise de curto-circuito é um método extremamente importante para os sistemas de energia elétrica (SEE), pois fornece os parâmetros necessários para o dimensionamento adequado dos equipamentos elétricos e ajuste dos dispositivos de proteção que garantem a segurança do SEE e contribuem para a redução dos riscos associados às pessoas próximas ao SEE. Assumindo o atual cenário de intensa inserção de fontes de energia renováveis no SEE, este trabalho propõe métodos e modelos matemáticos para representar os geradores distribuídos de fontes renováveis e não renováveis na análise de curto-circuito em sistemas de distribuição. As características da corrente de curto-circuito de quatro tecnologias de geradores distribuídos são apresentadas: síncrono, indução, fotovoltaico e gerador de indução duplamente alimentado (DFIG, do inglês, Doubly Fed Induction Generator). Neste trabalho considera-se um sistema elétrico trifásico desbalanceado real onde são realizadas simulações de faltas mono-, bi- e trifásicas permitindo, assim, avaliação e compreensão dos efeitos dessas tecnologias nas correntes de curto-circuito em redes de distribuição. Na análise de curto-circuito proposta, o método de varredura para cálculo do fluxo de potência em sistemas radiais, e/ou fracamente malhados, é utilizado na obtenção das condições de operação do sistema de distribuição. A determinação da matriz de impedância nodal com redução de Kron para cada gerador presente no SEE e o princípio da superposição são ut... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead. The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. Results are predominantly obtained from measurements on an experimental generator and numerical simulations. With the computational capacity available today it is possible to numerically analyse physical phenomena that previously could only be studied with analytical tools. Numerical models can also be expanded to encompass more than one aspect of generator operation in coupled field-circuit models without model complexity surpassing computer capability. Three studies of unbalanced magnetic pull, UMP, in synchronous salient pole generators constitute the main part of this thesis. The first is a study of how parallel stator circuits affect the unbalanced magnetic pull caused by rotor eccentricity. Depending on the relationship between the geometry of the separate circuits and the direction of the eccentricity it was found that parallel circuits could reduce the UMP substantially. Secondly, an investigation of the effect of damper winding configuration on UMP was performed. The results showed that damper winding resistivity and the distance between the damper bars in a pole determine the effectiveness of the damper winding in reducing the UMP. Simulations of a production machine indicate that the reduction can be substantial from damper windings with low resistivity. The third study analyses the consequences of field winding interturn short circuits. Apart from a resulting rotating unbalanced magnetic pull it is found that the unaffected poles with the same polarity as the affected pole experience an increase in flux density. In a fourth article a new stand still frequency response, SSFR, test method including measurements of damper winding voltage and current is presented. It is found that the identified models are capable of predicting the stator to damper transfer function both with and without the damper winding measurements included.

Ce travail est relatif à l’augmentation du courant de court-circuit du réseau électriqueportuaire alimentant le navire. Ceci passe par une modélisation des réseaux des charges, dutransformateur et enfin convertisseurs concernés. Munis de cette compréhension du système,diverses solutions à base d’électronique de puissance ou d’éléments passifs ont étéinvestiguées, simulées et évaluées à l’aune des performances exigées. Pour l’augmentation ducourant de court-circuit, un transformateur spécialement créé pour cette application à deuxenroulements primaires est proposé. L’esprit de la solution est de modifier la configuration dutransformateur au moment de la détection du court-circuit en modifiant son rapport detransformation. Un banc de test temps réel hybride a été architecturé afin de tester cettesolution. Les essais sur le banc de test ont permis d’obtenir des résultats satisfaisants etencourageants qui corroborent la théorie. Pour finir des études complémentaires, sousdifférents scenarii, ont été menées en simulation hors ligne. / This work is about the short-circuit current increase, inside the harbor’s electrical networkthat supplies the electrical grid of each vessel docked in port. We analyze the system’srequirements, the load demands, the transformer and finally the modeling of the convertersinvolved. Armed with this understanding of the system, various solutions like powerelectronics devices or passive equipments were investigated, simulated and evaluated in termsof performance requirements. To increase the short-circuit current, we provide a noveltransformer with two primary windings. The purpose of this solution is to change theconfiguration of the transformer when the short circuit is detected by changing thetransformation ratio. A real-time hybrid test bench has been build in order to test the solution.The real-time tests have yielded good and encouraging results, supporting the theory. Finally,further studies under various scenarios were conducted in offline simulations.

Darbe tiriami mažaanglio plieno S235J2 (LST EN 10025:2004) suvirintų siūlių pasikeitimai, plieną apvirinant skirtingais glaistytaisiais elektrodais ir suvirinimo režimais. Tyrimų metu buvo naudojami AV-23 ir AV-66 glaistytieji elektrodai bei keičiamas trumpojo jungimo srovės stipris. Nustatytas ryšys tarp metalo įvirinimo gylio, rumbelės aukščio, išlydytų lašų dydžio, išlydytų lašų kiekio, trumpojo jungimo trukmės ir trumpojo jungimo srovės dydžio. Gauti tyrimų rezultatai, nubraižyti priklausomybių grafikai ir pateiktos išvados. Darbą sudaro: įvadas, literatūros apžvalga, eksperimentuose naudojama įranga ir medžiagos, tyrimo metodika, tyrimų metu gauti rezultatai, grafikai, išvados, literatūra. Darbo apimtis: 83 p. teksto, 73 iliustr., 18 lent., 23 bibliografiniai šaltiniai. / In final work was analyzed the changes of seams properties of steel S235J2 (LST EN 10025:2004), produced by welding with different technology are discussed. Samples were welded by hand arc welding, using AV-23 and AV-66 welding electrodes. The welded seams were made by changing short-circuit current. The duration of weld depth, ridge height, metal drop size, metal drop frequency, short-circuit time and short-circuit current value are determinated. The results of the research are given in graphs, final conclusions are also written. Structure: the introduction, survey of the related literature, equipment and materials, description of the methodology, results of research, graphs of the results, conclutions, references. Thesis consist of: 83 p. text, 73 pictures, 18 tables, 23 bibliographical entries.

Ce travail est relatif à l’augmentation du courant de court-circuit du réseau électriqueportuaire alimentant le navire. Ceci passe par une modélisation des réseaux des charges, dutransformateur et enfin convertisseurs concernés. Munis de cette compréhension du système,diverses solutions à base d’électronique de puissance ou d’éléments passifs ont étéinvestiguées, simulées et évaluées à l’aune des performances exigées. Pour l’augmentation ducourant de court-circuit, un transformateur spécialement créé pour cette application à deuxenroulements primaires est proposé. L’esprit de la solution est de modifier la configuration dutransformateur au moment de la détection du court-circuit en modifiant son rapport detransformation. Un banc de test temps réel hybride a été architecturé afin de tester cettesolution. Les essais sur le banc de test ont permis d’obtenir des résultats satisfaisants etencourageants qui corroborent la théorie. Pour finir des études complémentaires, sousdifférents scenarii, ont été menées en simulation hors ligne. / This work is about the short-circuit current increase, inside the harbor’s electrical networkthat supplies the electrical grid of each vessel docked in port. We analyze the system’srequirements, the load demands, the transformer and finally the modeling of the convertersinvolved. Armed with this understanding of the system, various solutions like powerelectronics devices or passive equipments were investigated, simulated and evaluated in termsof performance requirements. To increase the short-circuit current, we provide a noveltransformer with two primary windings. The purpose of this solution is to change theconfiguration of the transformer when the short circuit is detected by changing thetransformation ratio. A real-time hybrid test bench has been build in order to test the solution.The real-time tests have yielded good and encouraging results, supporting the theory. Finally,further studies under various scenarios were conducted in offline simulations.

O presente trabalho apresenta estudos teóricos e uma revisão bibliográfica sobre diversos aspectos relevantes à qualidade da energia elétrica, principalmente os afundamentos de tensão em sistemas de energia elétrica. A avaliação da eficiência de um sistema elétrico de potência é quantificada por diversos fatores de qualidade, destacando-se a continuidade do fornecimento de energia elétrica aos consumidores. Nesse contexto, a análise de faltas é muito importante e demanda especial atenção quando do projeto do esquema de proteção e dos índices de qualidade do sistema elétrico de distribuição. Assim sendo, o presente trabalho apresenta uma comparação entre os métodos de cálculo de curtos circuitos convencionais: Método das Componentes Simétricas e o Método das Componentes de Fases. Também é apresentada uma nova aproximação da obtenção da matriz de impedância de cada elemento do sistema elétrico de potência, para a resolução pelo Método das Componentes Simétricas em sistemas desequilibrados. Usando um modelo particular de um sistema elétrico de distribuição são efetuadas simulações computacionais para avaliar o desempenho do algoritmo proposto. As simulações de curtos circuitos são realizadas com rotinas no ambiente MatLab e logo comparadas com os resultados do programa ATP/EMTP. Os cálculos de afundamentos de tensão são realizados para diferentes tipos de faltas: trifásica-terra (FFFT), fase-terra (FT), fase-fase (FF) e fase-fase-terra (FFT). Apesar de o trabalho estar centrado em sistemas de distribuição, as conclusões podem ser referidas a qualquer tipo de sistema de energia elétrica. Os resultados obtidos nessas simulações mostram que a aproximação proposta que consiste da obtenção da impedância de componentes simétricas de cada elemento, apresenta um ótimo desempenho. O objetivo desta comparação é identificar o método de cálculo de curto-circuito que ofereça a viabilidade de simplificação nos procedimentos de cálculo, como também na modelagem dos componentes do sistema elétrico de energia, mantendo continuamente uma boa precisão dos resultados dentro dos limites de tolerância. Com esta simplificação se pode reduzir significativamente o tempo das simulações, o processo de análise e tomada de decisão mais ágil e eficiente. / This work presents theoretical studies and a literature review on various aspects relevant to the quality of electric power, especially voltage sags in electric power systems. Assessing the efficiency of a power system is quantified by several quality factors, highlighting the continued supply of electricity to consumers. In this context, the analysis of faults is very important and demand special attention when designing the protection scheme and the quality indexes of the electrical system of distribution. Therefore, this work presents a comparison between the calculation methods of conventional short circuit: Method of Symmetrical Component and Method of Phases Components. It also presents a new approach to obtaining the impedance matrix of each element of the electric power system for the resolution by the Method of Symmetrical Components in unbalanced systems. Using a particular model of an electric distribution system computer simulations are carried out to evaluate the performance of the algorithm. Simulations of short circuits are performed with routines in MatLab environment and then compared with the results of the software ATP/EMTP. The calculations of voltage sags are performed for different types of faults: three-phase- ground (FFFT), phase-ground (FT), phase-phase (FF) and phase-phase- ground (FFT). Although the work is centered on distribution systems, the findings can be referred to any type of power system. The results obtained in these simulations show that the proposed approach consists of obtaining the impedance of symmetrical components of each element, presents a great performance. The purpose of this comparison is to identify the method of calculating short-circuit that provides the feasibility of simplifying the calculation procedures, but also in the modeling of system components, electric power, continuously keeping a good accuracy of results within the tolerance limits. With this simplification can significantly reduce the time of simulations, the process of analysis and decision making more agile and efficient.

Les arcs électriques de défaut se produisant entre deux câbles endommagés peuvent donner lieu à un phénomène appelé " arc tracking ", qui se caractérise par le maintien et la propagation de cet arc le long des câbles, entraînant leur ablation progressive. Dans un réseau aéronautique, un tel défaut peut avoir de graves conséquences lorsqu'il apparaît au sein d'un toron de câbles, d'autant plus qu'il est susceptible de se transférer à une structure avoisinante. Un dispositif expérimental a été développé pour l'étude de ce phénomène. Il est constitué d'une alimentation conçue selon des spécifications propres au domaine aéronautique, permettant de générer un signal continu ou alternatif pendant une durée réglable. Afin de se rapprocher des conditions de vol (pression réduite à haute altitude), les essais sont effectués au sein d'une enceinte fermée, soit à 1 bar, soit à 95 mbar. Trois types de câbles sont testés, un en aluminium et deux en cuivre. En régime continu, ils sont reliés au + et au - de l'alimentation, et à deux phases en régime alternatif. Une plaque en aluminium, représentant la structure de l'avion et connectée au neutre du générateur en régime alternatif, est placée en regard de la partie dénudée des câbles, là où se produit l'arc, permettant un éventuel transfert de l'arc depuis les câbles vers cette plaque. Chaque test s'accompagne de l'acquisition systématique des signaux de courant et de tension, et deux capteurs de flux radiatif sont positionnés autour de l'arc. Une caméra rapide permet la visualisation du comportement de l'arc au cours de l'essai. Enfin, les échantillons de câbles sont pesés avant et après chaque test. Un bilan de puissance est réalisé pour les différentes configurations testées (courant, pression, câbles), afin d'estimer la répartition de la puissance totale entre les électrodes (fusion et vaporisation des câbles, conduction, rayonnement) et la colonne de plasma (rayonnement, conduction, convection). La part transférée aux électrodes est estimée au moyen de la valeur de la chute de tension aux électrodes et du courant. Une partie de cette puissance aux électrodes est à l'origine de la fusion et de la vaporisation des câbles (le matériau isolant comme le métal). Celle-ci est estimée grâce à un calcul thermodynamique à partir de la masse de câble ablatée, en considérant que la totalité a été fondue et que 1% a été vaporisé. La puissance transmise à la colonne d'arc est en partie rayonnée, mais le spectre de longueurs d'onde inférieures à 200 nm est absorbé dès les premiers microns d'air, et une estimation est effectuée à partir du calcul coefficient d'émission nette. Une partie importante de l'étude a porté sur le transfert de l'arc à la plaque en aluminium, en fonction de la distance entre les câbles et cette plaque et selon un critère de température en face arrière, mesurée par thermographie infrarouge. Il a ainsi été montré qu'à pression réduite l'arc est beaucoup plus diffus, et a tendance à s'accrocher à la plaque en aluminium à des distances environ deux fois plus grandes qu'à pression atmosphérique. Cependant, la puissance totale disponible étant inférieure d'environ 20%, les dégâts à la plaque en aluminium sont moins importants. / Fault electric arcs occurring between two damaged wires may lead to a phenomenon called "arc tracking", which consists in a maintaining and propagating arc along the cables, causing their progressive ablation. In an aeronautical network, such a fault may have serious consequences if it happens within a wiring harness, especially as it is likely to transfer to a nearby structure. An experimental setup has been developed to study this phenomenon. It consists of a power supply designed in accordance with aeronautical specifications, which enables to generate a direct or alternating signal during an adjustable time. In order to reproduce flight conditions in a better way (low pressure at high altitude), tests are carried out within a closed chamber, whether at 1 bar pressure, or at 95 mbar pressure. Three types of cables are tested, one mainly made of aluminium and two mainly made of copper. In direct regime, they are connected to the + and the - poles of the generator, and to two phases in alternating regime. An aluminium plate, representing the aircraft structure and connected to the neutral in alternating regime, is placed in front of the stripped part of the cables, where the arc occurs, enabling a potential transfer of the arc from the cables toward the plate. Every test involves a systematic acquisition of the current and voltage signals, and two radiative flux sensors are positioned around the arc. A fast camera enables a viewing of the arc behaviour during the test. Finally, the sample is weighed before and after each test. A power balance is realised for the various tested configurations (current, pressure, cables), in order to estimate the distribution of the total power between the electrodes (fusion and vaporisation of the cables, but also conduction and radiation) and the plasma column (radiation, conduction, convection). The amount of power that is transferred to the electrodes is estimated with the value of the electrode voltage drop and the current. Part of this power makes the cables melt and vaporise (the insulating material as well as the metal), it is estimated with a thermodynamic calculation based on the ablated mass of cable, considering that the whole has been molten, and 1% vaporised. The amount of power transmitted to the arc column is partly radiated, but the wavelength spectrum emitted below 200 nm is absorbed through the very first microns in air, and estimation is made involving the calculation of the net emission coefficient. A significant part of the study was related to the transfer of the arc toward the aluminium plate, as a function of the distance between the cables and that plate, and according to a temperature criterion at the back side, by means of infrared thermography. Thus, it was shown that at low pressure, the arc is much less localised, and tends to transfer to the aluminium plate at distances around twice bigger than at atmospheric pressure. However, the total available power is around 20% smaller, and the damage caused to the aluminium plate is less severe.

The increasing demand for energy, coupled with the difficulties inherent in the implementation of large generation projects, significantly increased the use of energy resources from renewable energy sources, in order to better meet the energy market. Recent research shows that there are several benefits of using the Distributed Generation in relation to large enterprises Centralized Generation. In this sense, this work shows the results of studies conducted in order to verify the feasibility of taking advantage of the Distributed Generation to meet the remaining local loads in any power shortages Distributor. This operation is called Intentional Islanded Operation. In order to implement the intentional islanding operation of Distributed Generation, it is necessary to carry out specific studies to meet the levels of quality and continuity established by regulations and to ensure the safety of the electrical system. Thus, this work presents an analysis of the technical feasibility of intentional islanded operation of distributed generators, given the restrictions imposed resulting from Power Flow studies, Transient Stability and Short Circuit. / O crescente aumento da demanda de energia, associado às dificuldades inerentes à implantação de empreendimentos de geração de grande porte, aumentou significativamente o aproveitamento dos recursos energéticos a partir de fontes de energia renováveis, visando um melhor atendimento do mercado de energia. Pesquisas recentes mostram que há diversas vantagens em se utilizar a Geração Distribuída em relação aos grandes empreendimentos de Geração Centralizada. Neste sentido, esta dissertação mostra os resultados de estudos realizados com o objetivo de verificar a viabilidade em se aproveitar as Gerações Distribuídas para o atendimento das cargas locais remanescentes, em eventuais faltas de energia da Distribuidora. Esta operação é denominada de Operação Ilhada Intencional. Para que a operação ilhada de Geradores Distribuídos possa ser admitida, estudos específicos devem ser realizados, a fim de que os níveis de qualidade e continuidade exigidos pelos órgãos reguladores sejam atendidos e que a segurança do sistema elétrico seja preservada. Desta forma, esta dissertação apresenta uma análise da viabilidade técnica da operação ilhada intencional de Geradores Distribuídos, considerando as restrições resultantes impostas a partir de estudos de Fluxo de Potência, Estabilidade Transitória e Curto-Circuito.

O presente trabalho apresenta estudos teóricos e uma revisão bibliográfica sobre diversos aspectos relevantes à qualidade da energia elétrica, principalmente os afundamentos de tensão em sistemas de energia elétrica. A avaliação da eficiência de um sistema elétrico de potência é quantificada por diversos fatores de qualidade, destacando-se a continuidade do fornecimento de energia elétrica aos consumidores. Nesse contexto, a análise de faltas é muito importante e demanda especial atenção quando do projeto do esquema de proteção e dos índices de qualidade do sistema elétrico de distribuição. Assim sendo, o presente trabalho apresenta uma comparação entre os métodos de cálculo de curtos circuitos convencionais: Método das Componentes Simétricas e o Método das Componentes de Fases. Também é apresentada uma nova aproximação da obtenção da matriz de impedância de cada elemento do sistema elétrico de potência, para a resolução pelo Método das Componentes Simétricas em sistemas desequilibrados. Usando um modelo particular de um sistema elétrico de distribuição são efetuadas simulações computacionais para avaliar o desempenho do algoritmo proposto. As simulações de curtos circuitos são realizadas com rotinas no ambiente MatLab e logo comparadas com os resultados do programa ATP/EMTP. Os cálculos de afundamentos de tensão são realizados para diferentes tipos de faltas: trifásica-terra (FFFT), fase-terra (FT), fase-fase (FF) e fase-fase-terra (FFT). Apesar de o trabalho estar centrado em sistemas de distribuição, as conclusões podem ser referidas a qualquer tipo de sistema de energia elétrica. Os resultados obtidos nessas simulações mostram que a aproximação proposta que consiste da obtenção da impedância de componentes simétricas de cada elemento, apresenta um ótimo desempenho. O objetivo desta comparação é identificar o método de cálculo de curto-circuito que ofereça a viabilidade de simplificação nos procedimentos de cálculo, como também na modelagem dos componentes do sistema elétrico de energia, mantendo continuamente uma boa precisão dos resultados dentro dos limites de tolerância. Com esta simplificação se pode reduzir significativamente o tempo das simulações, o processo de análise e tomada de decisão mais ágil e eficiente. / This work presents theoretical studies and a literature review on various aspects relevant to the quality of electric power, especially voltage sags in electric power systems. Assessing the efficiency of a power system is quantified by several quality factors, highlighting the continued supply of electricity to consumers. In this context, the analysis of faults is very important and demand special attention when designing the protection scheme and the quality indexes of the electrical system of distribution. Therefore, this work presents a comparison between the calculation methods of conventional short circuit: Method of Symmetrical Component and Method of Phases Components. It also presents a new approach to obtaining the impedance matrix of each element of the electric power system for the resolution by the Method of Symmetrical Components in unbalanced systems. Using a particular model of an electric distribution system computer simulations are carried out to evaluate the performance of the algorithm. Simulations of short circuits are performed with routines in MatLab environment and then compared with the results of the software ATP/EMTP. The calculations of voltage sags are performed for different types of faults: three-phase- ground (FFFT), phase-ground (FT), phase-phase (FF) and phase-phase- ground (FFT). Although the work is centered on distribution systems, the findings can be referred to any type of power system. The results obtained in these simulations show that the proposed approach consists of obtaining the impedance of symmetrical components of each element, presents a great performance. The purpose of this comparison is to identify the method of calculating short-circuit that provides the feasibility of simplifying the calculation procedures, but also in the modeling of system components, electric power, continuously keeping a good accuracy of results within the tolerance limits. With this simplification can significantly reduce the time of simulations, the process of analysis and decision making more agile and efficient.