<p>Detta examensarbete beskriver hur en Monte Carlo simulering (MCS) kan användas för tillförlitlighetsanalys av ett eldistributionssystem. Metoden har implementerats i verktyget RADPOW som nu kan utföra både analytiska och numeriska beräkningar. Angreppssättet för att utveckla denna MCS metod i RADPOW innefattade följande aktiviteter:</p><p>• Vidareutvecklade av RADPOW med införandet av ett grafiskt användargränssnitt för Windows.</p><p>• Utveckling och implementering av en iterativ analytisk metod för känslighetsanalys av eldistributionssystem i RADPOW.</p><p>• Utveckling och implementering av MCS metoden i RADPOW, vilken placerades i en fristående modul kallad Sim.</p><p>Den implementerade MCS metoden har validerats i en jämförande studie innefattande två testsystem med datorprogrammet NEPLAN. Resultat från denna studie visar att MCS metoden ger samma resultat som den analytiska metoden i RADPOW och det kommersiella verktyget NEPLAN.</p> / <p>This master thesis describes an implementation of a Monte Carlo Simulation (MCS) method for reliability assessment of electrical distribution systems. The method has been implemented in the reliability assessment tool RADPOW which now is able to perform both analytical and simulation evaluations. The main contributions within this thesis includes the following activities;</p><p>• Further development of RADPOW by the introducing of a graphical user interface for Windows.</p><p>• Development and implementation of an analytical sensitivity analysis routine for RADPOW.</p><p>• Development and implementation of a sequential MCS method in RADPOW in a stand alone module referred to as Sim.</p><p>The implemented MCS method has been validated in a comparable study for two case systems by a commercial software NEPLAN. Results shows that the implemented MCS method provides the same results as the analytical method in RADPOW and the NEPLAN software.</p>

Made available in DSpace on 2014-06-11T19:22:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-24Bitstream added on 2014-06-13T19:06:59Z : No. of bitstreams: 1 alves_rp_me_ilha.pdf: 1636703 bytes, checksum: 68dadb3a2996ae56b4ce5e5e3e063a2d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho apresenta o desenvolvimento de uma formulação linear inteira mista (equivalente à formulação não linear inteira mista) para resolver o problema de alocação de reguladores de tensão ao longo dos alimentadores primários de sistemas de distribuição de energia elétrica radiais, com o objetivo de melhorar o perfil da magnitude de tensão, reduzir as perdas de potência ativa da rede e a minimização dos custos de instalação dos equipamen-tos. Na formulação proposta, o cálculo do ponto de operação em regime permanente de um sistema de distribuição radial é modelado matematicamente usando expressões lineares. O uso de um modelo de programação linear inteira mista garante a convergência para a solução óti-ma usando ferramentas de otimização clássica existentes. Os sistemas testes de 70-, 136-, 202- e 400-nós são utilizados para mostrar a precisão do modelo matemático, assim como também a eficiência da técnica de solução proposta para resolver o problema de alocação de reguladores de tensão em um sistema de distribuição radial / This work shows the development of a mixed integer linear formulation to solve the voltage regulators allocation problem in radial electrical distribution systems, with the goal of improving the voltage magnitude profile, reducing the active power losses and mini-mizing the investment cost. In the proposed formulation, the steady-state operation point of the radial distribution system is modeled through linear expressions. The use of a mixed-integer linear formulation guarantees convergence to optimality using existing optimization software. The 70-, 136-, 202- and 400-node test systems are used in order to show the accura-cy of the mathematical model as well as the efficiency of the proposed solution technique to solve the allocation problem of voltage regulators in a radial distribution system

Orientador: Marcos Julio Rider Flores / Banca: Rubén Augusto Romero Lázaro / Banca: Carlos Alberto Castro Júnior / Resumo: O presente trabalho apresenta o desenvolvimento de uma formulação linear inteira mista (equivalente à formulação não linear inteira mista) para resolver o problema de alocação de reguladores de tensão ao longo dos alimentadores primários de sistemas de distribuição de energia elétrica radiais, com o objetivo de melhorar o perfil da magnitude de tensão, reduzir as perdas de potência ativa da rede e a minimização dos custos de instalação dos equipamen-tos. Na formulação proposta, o cálculo do ponto de operação em regime permanente de um sistema de distribuição radial é modelado matematicamente usando expressões lineares. O uso de um modelo de programação linear inteira mista garante a convergência para a solução óti-ma usando ferramentas de otimização clássica existentes. Os sistemas testes de 70-, 136-, 202- e 400-nós são utilizados para mostrar a precisão do modelo matemático, assim como também a eficiência da técnica de solução proposta para resolver o problema de alocação de reguladores de tensão em um sistema de distribuição radial / Abstract: This work shows the development of a mixed integer linear formulation to solve the voltage regulators allocation problem in radial electrical distribution systems, with the goal of improving the voltage magnitude profile, reducing the active power losses and mini-mizing the investment cost. In the proposed formulation, the steady-state operation point of the radial distribution system is modeled through linear expressions. The use of a mixed-integer linear formulation guarantees convergence to optimality using existing optimization software. The 70-, 136-, 202- and 400-node test systems are used in order to show the accura-cy of the mathematical model as well as the efficiency of the proposed solution technique to solve the allocation problem of voltage regulators in a radial distribution system / Mestre

The collective electric transport can be considered as one of the best alternatives to reduce the concentration of pollutants in urban centers, because it reduces the number of vehicles in circulation and eliminates most of the problems arising from the use of fossil fuels. Currently, in this alternative, there is a wide range of options available, however, with the advancement occurred in recent years in terms of battery technology, the pure electric bus has stood out due to advantages related to its flexibility, sustainability and adaptability to the existing infrastructure. However, the use of these vehicles requires special recharging stations, which drain a lot of energy of the grid, in a short time, a feature that generates a significant impact on electrical systems. Moreover, the high amount of energy required for the operation of these vehicles precludes the use of technology in certain places, because it requires large investments in infrastructure for power supply, which often do not is available locally in the short term. Based on this, this dissertation presents a study of the impact generated in the electrical distribution system caused by the replacement of a diesel bus fleet by electric buses in a small town in southern Brazil. The study was based on the measurement of energy consumption through data related to the lines and the vehicle driving cycle, applied to an electric bus model, it was developed with Matlab software. Actual data of the lines was used, as distance, speeds, tilt, number of passengers, among others, obtained through a GPS equipment and information provided by the company analyzed. At the end were generated values related to the energy consumption of vehicles in each of the lines, the electricity consumption increase generated by the substitution in question and an estimate of the daily load curves based on the operating hours of the analyzed lines. / O transporte elétrico coletivo atualmente pode ser considerado como uma das melhores alternativas para a redução da concentração de poluentes em centros urbanos, pois reduz o número de veículos em circulação e elimina a maioria dos problemas decorrentes do uso de combustíveis fósseis. Atualmente, neste tipo de alternativa existe uma vasta gama de opções disponíveis, entretanto, com o avanço ocorrido nos últimos anos em termos de tecnologia de baterias, os ônibus elétricos puros vem se destacando devido a vantagens relacionadas a sua flexibilidade, sustentabilidade e adaptabilidade as infraestruturas existentes. Porém a utilização destes veículos requer estações de recarga especiais, as quais causam um impacto significativo nos sistemas elétricos, pois geram um grande acréscimo de demanda de energia, o que em alguns casos pode sobrecarregar os sistemas. Além disso, a elevada quantidade de energia necessária para a operação destes veículos inviabiliza o uso da tecnologia em determinados locais, pois requer um alto investimento em infraestrutura para o fornecimento seguro e confiável de energia. Baseado nisto, esta dissertação apresenta um estudo do impacto gerado no sistema elétrico de distribuição ocasionado pela substituição de uma frota de ônibus a diesel por ônibus elétricos em uma cidade de pequeno porte situada no sul do Brasil. O estudo foi baseado na mensuração do consumo energético através de dados relacionados às linhas e ao ciclo de condução dos veículos, aplicados em um modelo de ônibus elétrico, o qual foi elaborado através do software Matlab®. Foram utilizados dados reais das distâncias nas linhas, velocidades, relevo das vias, número de passageiros, entre outros, obtidos através de um equipamento de GPS e informações fornecidas pela empresa analisada. Ao final foram gerados valores relacionados ao consumo dos veículos em cada uma das linhas, o acréscimo de consumo de energia elétrica gerado pela substituição em questão e uma estimativa das curvas de carga diárias baseadas nos horários de operação das linhas analisadas.

En 2010, ERDF (Electricité Réseau Distribution France) a entamé la mise en place du projet « Linky » dont l'objectif est d'installer 35 millions de compteurs intelligents en France. Ces compteurs permettront de collecter les données de consommation en « temps réel », avec lesquelles des modèles de charge plus précis pourront être envisagés. Dans ce contexte, cette thèse définit deux objectifs: la définition de modèles prédictifs de charge pour la conduite et la conception de modèles d'estimation de charge pour la planification. En ce qui concerne la conduite, nous avons développés deux modèles. Le premier exploite le formalisme mathématique des séries chronologiques ; le second est basé sur un réseau de neurones. Les deux modèles cherchent à prévoir la charge des jours « J+1 » et « J+2 » à partir des informations collectées jusqu'au jour « J ». Le modèle « série chronologique » repose sur les propriétés temporelles des courbes de charge. Ainsi on découpe la courbe de charge en trois parties : la tendance, la périodicité et le résidu. Les premiers deux sont déterministes et indépendamment développés en deux modèles : le modèle de tendance et le modèle de cyclicité. La somme de la prévision de ces deux modèles est la prévision finale. Le résidu quant à lui capture les phénomènes aléatoires que présente la courbe de charge. Le modèle de prédiction ainsi développé s'aide de nombreux outils statistiques (e.g., test de stationnarité, test ANOVA, analyse spectrale, entres autres) pour garantir son bon fonctionnement. Enfin, modèle « série chronologique » prend en compte plusieurs facteurs qui expliquent la variation dans la courbe de consommation tels que la température, les cyclicités, le temps, et le type du jour, etc. En ce qui concerne le modèle à base de réseaux de neurones, nous nous focalisons sur les stratégies de sélection de la structure pour un modèle optimal. Les choix des entrées et du nombre de neurones cachés sont effectués à travers les méthodes dites de «régression orthogonale » et de « leave-one-out-virtuel ». Les résultats montrent que la procédure proposée permet de choisir une structure de réseau de neurones qui garantisse une bonne précision de prédiction. En ce qui concerne la planification, un modèle non paramétrique est proposé et comparé avec le modèle actuel « BAGHEERA » d'EDF. Avec l'ouverture du marché d'électricité, la relation entre les fournisseurs, les clients et les distributeurs devient flexible. Les informations qualitatives d'un client particulier telles que sa puissance souscrite, son code d'activité, ses tarifs etc. sont de moins en moins disponibles. L'évolution du modèle BAGHEERA qui dépend ces informations pour classer les clients dans différentes catégories est devenue indispensable. Le modèle non paramétrique est un modèle individuel centré sur le relevé des compteurs. Trois variables de régression non paramétriques : Nadaraya Watson, Local Linear et Local Linear adapted ont été analysées et comparées. Les scénarios de validation montrent que le modèle non paramétrique est plus précis que le modèle « BAGHEERA ». Ces nouveaux modèles ont été conçus et validés sur de vraies données collectées sur le territoire français. / From 2010, ERDF (French DSO) started the “Linky” project. The project aims at installing 35 millions smart meters in France. These smart meters will collect individual client's consumption data in real time and transfer these data to the data center automatically in a certain frequency. These detailed consumption information provided by the smart metering system enables the designs of more accurate load models. On this purpose, two distinctive objectives are defined in this dissertation: the forecasting load models for the operation need and the estimation load models for the planning need. For the operation need, two models are developed, respectively relying on the “time series” and the “neural network” principals. They are both for the objective of predicting the loads in “D+1” and “D+2” days based on the historical information till “D” day. The “time series” model divides the load curve into three components: the trend, the cyclic, and the residual. The first two parts are deterministic, from which two models named the trend model and the cyclic model are made. The sum of the prevision of these two models is the final prediction result. For a better precision, numerous statistical tools are also integrated such that the stationary test, the smoothed periodogram, the ANOVA test and the gliding window estimation, etc. The time series model can extract information from the influence factors such as the time, the temperature, the periodicities and the day type, etc. Being the most popular non linear model and the universal approximator, the neural network load forecasting model is also studied in this dissertation. We focus on the strategy of the structure selection. The work is in collaboration with Prof. Dreyfus (SIGMA lab), a well known expert in the machine learning field. Input selection and model selection are performed by the “orthogonal forward regression” and the “virtual-leave-one-out” algorithms. Results show that the proposed procedure is efficient and guarantees the chosen model a good accuracy on the load forecasting. For the planning, a nonparametric model is designed and compared with the actual model “BAGHEERA” of the French electricity company EDF. With the opening of the electricity market, the relationship among the regulators, suppliers and clients is changing. The qualitative information about a particular client such as his subscribed power, his activity code and his electricity tariffs becomes less and less available. The evolution from the BAGHEERA model to a data-driven model is unavoidable, since the BAGHEERA model depends on these information to attribute every client in the French territory into a pre-defined category. The proposed nonparametric model is individualized and can deal with both temperature sensitive (possessing an electrical heater) and temperature insensitive clients. Three nonparametric regressors are proposed: the Nadaraya Watson, the local linear, and the local linear adapted. The validation studies show that the nonparametric model has a better estimation precision than the BAGHEERA model. These novel models are designed and validated by the real measurements collected in the French distribution network.

Detta examensarbete beskriver hur en Monte Carlo simulering (MCS) kan användas för tillförlitlighetsanalys av ett eldistributionssystem. Metoden har implementerats i verktyget RADPOW som nu kan utföra både analytiska och numeriska beräkningar. Angreppssättet för att utveckla denna MCS metod i RADPOW innefattade följande aktiviteter: • Vidareutvecklade av RADPOW med införandet av ett grafiskt användargränssnitt för Windows. • Utveckling och implementering av en iterativ analytisk metod för känslighetsanalys av eldistributionssystem i RADPOW. • Utveckling och implementering av MCS metoden i RADPOW, vilken placerades i en fristående modul kallad Sim. Den implementerade MCS metoden har validerats i en jämförande studie innefattande två testsystem med datorprogrammet NEPLAN. Resultat från denna studie visar att MCS metoden ger samma resultat som den analytiska metoden i RADPOW och det kommersiella verktyget NEPLAN. / This master thesis describes an implementation of a Monte Carlo Simulation (MCS) method for reliability assessment of electrical distribution systems. The method has been implemented in the reliability assessment tool RADPOW which now is able to perform both analytical and simulation evaluations. The main contributions within this thesis includes the following activities; • Further development of RADPOW by the introducing of a graphical user interface for Windows. • Development and implementation of an analytical sensitivity analysis routine for RADPOW. • Development and implementation of a sequential MCS method in RADPOW in a stand alone module referred to as Sim. The implemented MCS method has been validated in a comparable study for two case systems by a commercial software NEPLAN. Results shows that the implemented MCS method provides the same results as the analytical method in RADPOW and the NEPLAN software.

<p>The Swedish electricity market was de-regulated in 1996, followed by new laws and a new regulation applied to the natural monopolies of electrical distribution systems (EDS). These circumstances have motivated distribution systems operators (DSOs) to introduce more comprehensive analysis methods. The laws, the regulation and additional incentives have been investigated within this work and results from this study can be valuable when developing risk methods or other quantitative methods applied to EDS. This tendency is not unique for Sweden, the results from a comparative study of customer outage compensation laws between Sweden and UK is for example included.</p><p>As a part of investigating these incentives, studies of the Swedish regulation of customer network tariffs have been performed which provide valuable learning when developing regulation models in different countries. The Swedish regulatory model, referred to as the Network Performance Assessment Model (NPAM), was created for one of the first de-regulated electricity markets in the world and has a unique and novel approach. For the first time, an overall presentation of the NPAM has been performed including description of the underlying theory as a part of this work. However, the model has been met by difficulties and the future usage of the model is uncertain. Furthermore, the robustness of the NPAM has been evaluated in two studies with the main conclusion that the NPAM is sensitive toward small variations in input data. Results from these studies are explained theoretically investigating algorithms of the NPAM.</p><p>A pre-study of a project on developing international test systems is presented and this ongoing project aims to be a useful input when developing risk methods. An application study is included with the approach to systematically describe the overall risk management process at a DSO including an evaluation and ideas of future developments. The main objective is to support DSOs in the development of risk management, and to give academic reference material to utilize industry experience. An idea of a risk management classification has been concluded from this application study. The study provides an input to the final objective of a quantitative risk method.</p>

The Swedish electricity market was de-regulated in 1996, followed by new laws and a new regulation applied to the natural monopolies of electrical distribution systems (EDS). These circumstances have motivated distribution systems operators (DSOs) to introduce more comprehensive analysis methods. The laws, the regulation and additional incentives have been investigated within this work and results from this study can be valuable when developing risk methods or other quantitative methods applied to EDS. This tendency is not unique for Sweden, the results from a comparative study of customer outage compensation laws between Sweden and UK is for example included. As a part of investigating these incentives, studies of the Swedish regulation of customer network tariffs have been performed which provide valuable learning when developing regulation models in different countries. The Swedish regulatory model, referred to as the Network Performance Assessment Model (NPAM), was created for one of the first de-regulated electricity markets in the world and has a unique and novel approach. For the first time, an overall presentation of the NPAM has been performed including description of the underlying theory as a part of this work. However, the model has been met by difficulties and the future usage of the model is uncertain. Furthermore, the robustness of the NPAM has been evaluated in two studies with the main conclusion that the NPAM is sensitive toward small variations in input data. Results from these studies are explained theoretically investigating algorithms of the NPAM. A pre-study of a project on developing international test systems is presented and this ongoing project aims to be a useful input when developing risk methods. An application study is included with the approach to systematically describe the overall risk management process at a DSO including an evaluation and ideas of future developments. The main objective is to support DSOs in the development of risk management, and to give academic reference material to utilize industry experience. An idea of a risk management classification has been concluded from this application study. The study provides an input to the final objective of a quantitative risk method. / QC 20101125

In today’s society the electric grid has become one of the most important infrastructures and industries as well as other infrastructures, and individuals rely on its functionality. The unavailability of electricity caused by outages is increasingly rare but when it occurs it can have serious consequences. An electric grid’s reliability is now a requirement, not only from customers but also from the regulatory authority.The electric grid in Stockholm is owned and operated by Ellevio AB. Over the past decade the reliability, measured in SAIDI (System Average Interruption Duration Index), in the area has deterioated, mainly due to failures of the medium voltage grid (11- kV, MV). The network structure on the MV- grid consists primarily of two parallel medium voltage cables each of which acts redundantly to its pair cable. The technique, called dual cable structure, works most optimally with substations with automatic switching, which automaticly switch over to the redundant cable when failure occurs. However substations without this automatic switching are widely used resulting in a longer interruption time. Another network structure is the ring or loop structure, which still has redundancy, but when failure occurs a load- break switch must close so that the grid can be fed from another direction. The substation in the loop structure can also be remotely controlled, making the load-break swith operable from the control center, resulting in a shorter interruption time.This thesis evaluates and compares different network structures consisting of dual cable with automatic switching and loop structure with remotely controlled substations, based on economy and reliability, on Stora Essingen. The two structures have been designed in the network information system program Trimble NIS and divided into two different environments; one developed and one undeveloped environment. The results show that the technical solutions in network structures of MV- grid do not necessarily mean major differences in economy nor reliability, rather the choice between few but long interruptions and many but short interruptions is central. Results show however that a combination of the dual cable structure with remotely controlled substations in the undeveloped environment is economically motivated while the reliability can be maintained at the same tame.