Šiame darbe nagrinėjamos Akmenės transformatorių pastotės elektros tinklo gedimų bei patikimumo didinimo problemos, remiantis mokslinės literatūros analize ir praktinio darbo patirties apibendrinimu. Nustatomi Akmenės transformatorių pastotės elektros tinklo 0,4-10 kV linijų gedimų skaičius, atjungtų vartotojų skaičius, atjungimų trukmės ir priežastys. Apskaičiuojami Akmenės transformatorių pastotės elektros tinklo patikimumo rodikliai, daugiausiai gendančios elektros linijos parengties ir priverstinės prastovos koeficientai bei gedimo ir veikimo tikimybės per 12 mėnesių. / This paper deals with Akmenės transformer substation power supply failure, and increase the robustness of the problem based on the scientific literature and practical experience summary. Setting Akmenės transformer substation power supply 0.4-10 kV line number of faults, the number of disconnection, disconnection times and causes. Calculate Akmenės transformer substation power supply reliability indicators, mostly perishable standby power lines and forced inactivity rates and the probability of failure and operational within 12 months.

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η μελέτη Υποσταθμού ΜΤ – ΧΤ. Αναλύονται τα μέσα που χρησιμοποιούνται για την υλοποίηση ενός ιδιωτικού Υ/Σ ΜΤ, ενώ μελετάται εκτενέστερα η διαδικασία επιλογής των μέσων εκείνων που είναι αναγκαία για την ηλεκτροδότηση ενός Μηχανουργείου, το οποίο αποτελείται από φορτία κίνησης και φωτισμού. Η εργασία χωρίζεται από δύο μέρη. Στο πρώτο μέρος, που είναι η εισαγωγή, παρατίθενται τα απαραίτητα θεωρητικά στοιχεία για την μελέτη και την σχεδίαση ενός Υ/Σ. Συγκεκριμένα, αναλύονται τα μέσα ζεύξης – απόζευξης και προστασίας ΜΤ καθώς και ο εξοπλισμός για το δίκτυο ΜΤ. Παρουσιάζονται οι τύποι παροχής των ιδιωτικών Υ/Σ, τα κατάλληλα είδη γείωσης για προστασία των ατόμων που εργάζονται σε αυτούς ή βρίσκονται κοντά, από επικίνδυνες τάσεις επαφής και βηματικές τάσεις, όπως επίσης και η απαραίτητη προστασία του Υ/Σ έναντι υπερτάσεων. Στην συνέχεια, επισημαίνονται τα χαρακτηριστικά στοιχεία, καθώς και οι τρόποι επιλογής και προστασίας των Μ/Σ ισχύος, οι οποίοι έχουν τον ρόλο του μετασχηματισμού της τάσης από ΜΤ σε ΧΤ. Γίνεται μια αναφορά στα καλώδια ΜΤ και ΧΤ και αναλύονται τα μέσα ζεύξης – απόζευξης και προστασίας ΧΤ. Επιπλέον περιγράφονται οι ηλεκτρικοί πίνακες μέσα στους οποίους τοποθετούνται τα μέσα ζεύξης και προστασίας. Επισημαίνεται η αναγκαιότητα της αντιστάθμισης αέργου ισχύος και γίνεται μια αναφορά στα συστήματα πυροπροστασίας και στην επιβεβλημένη συντήρηση του Υ/Σ. Τέλος παρουσιάζονται τα απαραίτητα εκείνα στοιχεία για τον υπολογισμό των ηλεκτρικών εγκαταστάσεων ισχυρών ρευμάτων των βιομηχανικών χώρων, οι οποίοι αποτελούνται από εγκαταστάσεις κίνησης και φωτισμού. Στο δεύτερο μέρος, πραγματοποιείται μια μελέτη εγκατάστασης κίνησης και φωτισμού ενός Μηχανουργείου καθώς επίσης και η μελέτη επιλογής των μέσων υλοποίησης του ιδιωτικού Υ/Σ ΜΤ – ΧΤ παροχής τύπου Α1 που θα το τροφοδοτήσει. Ακολουθούν τρία σχέδια, της χωροθέτησης των μηχανών παραγωγής έργου του Μηχανουργείου, της κάτοψης του κτιρίου του Υ/Σ ΜΤ και το μονογραμμικό του διάγραμμα στο οποίο φαίνονται όλα τα απαραίτητα στοιχεία για την κατασκευή των ηλεκτρικών πινάκων και την σχεδίαση της ηλεκτρολογικής εγκατάστασης. / Intention of the present diplomatic essay is the study of a Middle/Low Voltage’s Substation. The means used for the implementation of a private Middle Voltage’s Substation are being analyzed, whereas there is a further study of the procedure used to choose the specific means that are necessary for the power supply of a machine shop, which is consisted of movement and lighting loads. This essay is divided into two parts. In the first part, which is the introduction, all the essential theoretical information for calculating and designing a Substation is given. More specific, there is an analysis of the means of connection-disconnection and Middle Voltage protection structures, as well as the equipment for The M/V network. There is a presentation of the types of supplying private Substations and the proper grounding methods which protect people who work at them or stand close to them from dangerous types of voltages. Also the necessary protection of the Substation from overvoltage is mentioned. The technical characteristics, and the ways to select and to protect the Transformers, whose role is to transform the Middle Voltage to Low Voltage are presented next. There is a reference to the M/L Voltage cables and to the means of connection-disconnection and Low Voltage protection structures. Furthermore there is a description of the electrical boards, in which the means of connection and protection are placed. The necessity for counterbalancing the reactive power is highlighted and also the fire protection systems and the obligatory maintenance of the Substation are referred. Concluding the first part there is a presentation of the information needed to estimate electrical installations of industrial buildings, which are composed of motion and lighting installations. In the second part, there is an installation study for motion and lighting of a machine shop as well as a case study of the different structures available for setting up a private Substation M/L Voltage type A1 that will provide electrical power. Then there are three drawings. The first is about placing the different types of product machines of the machine shop, the ground plan of the M/V Substation’s building and the monoline diagram, in which all the essential information for constructing the electrical board and designing the electrical installation are showed.

Detta examensarbete är utfört på uppdrag av Rejlers Ingenjörer i Göteborg. Syftet med arbetet är att genom en projektering övergripande presentera utförandet, komponenter, funktioner, ekonomi och situationsplaner för två förslag på stationsutformningar i samband med en ombyggnation och utvidgning av en transformatorstation. Transformatorstationen har i nuläget två spänningsnivåer på 40 kV och 10 kV. I samband med ombyggnationen skall stationen kompletteras med ytterligare en spänningsnivå på 20 kV, för anslutning av ett antal vindkraftverk. För att anläggningen skall uppfylla grundläggande krav, utförs projekteringen genom att sortera och sammanställa relevant information från gällande föreskrifter, standarder och tekniska riktlinjer. Vidare inhämtas ytterligare information från litteratur, kataloger, produktblad och muntlig kontakt med uppdragsgivaren. I arbetet presenteras två förslag på stationsutformningar i enlighet med syftet. Stationens högspänningsapparater dimensioneras och presenteras, och dess reläskyddsfunktioner identifieras. I båda alternativen är transformatorerna placerade utomhus med en stationsbyggnad som rymmer 10 kV-, 20 kV-ställverket, ett batterirum och ett kontrollrum. Skillnaden mellan alternativen ligger främst i att ett av alternativen har ett utomhusbyggt luftisolerat 40 kV-ställverk medan det andra alternativet har ett kompaktare inomhusbyggt luftisolerat 40 kV-ställverk. Den totalt beräknade kostnaden, inklusive drift- och underhållskostnader, under en 25-årsperiod beräknas uppgå till 22,7 Mkr för utomhusalternativet och 22,4 Mkr för inomhusalternativet. Skillnaden mellan alternativen förväntas stiga till inomhusalternativets fördel, om även samhällskostnader vid avbrott vägs in i kalkylen. Rekommendationen är att transformatorstationen uppförs enligt inomhusalternativet, eftersom detta torde anses ge bäst totalekonomi, driftsäkerhet och skydd mot obehörigt tillträde. / This bachelor´s thesis is carried out on behalf of Rejlers Ingenjörer in Gothenburg. The work aims to overall present the realization of two station design proposals, including components, functions, financial aspects and plans, in connection with a reconstruction and expansion of a substation. The substation currently has two voltage levels of 40 kV and 10 kV. In connection with the reconstruction, the station is supplemented by a further voltage level of 20 kV, for connection of a number of wind turbines. For the installation to meet basic requirements, the work is performed by sorting and putting together relevant information from applicable regulations, standards and technical guidelines. Further information is obtained through additional information from literature, catalogues, product sheets and verbal contact with the job requestor. In the thesis the two station design proposals are presented in compliance with the aim. The high voltage equipment is dimensioned and presented, and the relay protection functions are identified. In both options, the transformers are located outdoors with a station building that houses 10 kV, 20 kV switchgear, a battery room and a control room. The main difference between the alternatives is that one of the options has an outdoor air insulated 40 kV switchgear, while the second one has a more compact indoor air insulated switchgear. The total estimated cost, including operation and maintenance costs, over a 25-year period is estimated at 22.7 million Swedish kronor for the outdoor option and 22.4 million Swedish kronor for the indoor alternative. The difference in costs is expected to rise to the advantage of the indoor option if social costs during a power failure also are taken into account in the calculation. It is recommended that the substation be built according to the indoor option, since this is considered to provide the best overall economy, safety of operation and protection against unauthorized access.

Protection and Control (P&C) devices requiring accurate timing within a power transmission substation are commonly synchronized by distributed Global Positioning System (GPS) receivers. However, utilities now request a timing system that is less dependent on the direct use of distributed GPS receivers, because of the reliability issue of GPS receivers. In addition, to reduce device-to-device cabling and enable interoperability among devices from multiple vendors, utilities are looking to adopt the Ethernet based IEC 61850 protocol suites to complement or replace a conventional hardwired secondary P&C system. The IEEE 1588-2008 synchronization protocol is a network based time synchronization technique which can co-exist with the IEC 61850 applications and deliver sub-microsecond timing accuracy. A number of IEC 61850 applications require seamless communication redundancy, whilst existing technologies used in a substation only recover communications tens of milliseconds after a communication failure. Alternatively, the newly released IEC 62439-3 Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) can achieve seamless redundancy by transmitting duplicate data packets simultaneously in various networks and this can satisfy the extremely high reliability requirements of transmission substations. Considering the benefits, a unified network integrating IEEE 1588 and IEC 62439 PRP/HSR can be foreseen in future substations, but utilities need confidence in these technologies before real deployment. Hence, it is necessary to conduct comprehensive tests on such a timing system so that better insight into the performance and limitation can be obtained. This thesis first investigates the feasibility to integrate IEEE 1588 and IEC 62439 PRP into a single Ethernet network using a simulation tool and subsequently presents how the hardware testbed is established. Meanwhile, although GPS receivers are commonly used for time synchronization in the power industry, their performance might not be fully investigated before deployment. Hence, this thesis also proposes a procedure to assess the performance in terms of long term stability and transient behaviour of a timing system merely based on GPS receivers and one based on a mixture of GPS receivers and IEEE 1588 devices. Test results indicate whichever system is used, careful design of equipment, proper installation and appropriate engineering are required to satisfy the stringent accuracy requirements for critical automation applications in power system.

abstract: Prior work in literature has illustrated the benefits of using surge arrester as a way to improve the lighting performance of the substation and transmission line. Installing surge arresters would enhance the system reliability but it comes with an extra capital expenditure. This thesis provides simulation analysis to examine substation-specific applications of surge arrester as a way of determining the optimal, cost-effective placement of surge arresters. Four different surge arrester installation configurations are examined for the 500/230 kV Rudd substation which belongs to the utility, Salt River Project (SRP). The most efficient configuration is identified in this thesis. A new method “voltage-distance curve” is proposed in this work to evaluate different surge arrester installation configurations. Simulation results show that surge arresters only need to be equipped on certain location of the substation and can still ensure sufficient lightning protection. With lower tower footing resistance, the lightning performance of the transmission line can typically be improved. However, when surge arresters are installed in the system, the footing resistance may have either negative or positive effect on the lightning performance. Different situations for both effects are studied in this thesis. This thesis proposes a surge arrester installation strategy for the overhead transmission line lightning protection. In order to determine the most efficient surge arrester configuration of transmission line, the entire transmission line is divided into several line sections according to the footing resistance of its towers. A line section consists of the towers which have similar footing resistance. Two different designs are considered for transmission line lightning protection, they include: equip different number of surge arrester on selected phase of every tower, equip surge arresters on all phases of selected towers. By varying the number of the towers or the number of phases needs to be equipped with surge arresters, the threshold voltage for line insulator flashover is used to evaluate different surge arrester installation configurations. The way to determine the optimal surge arresters configuration for each line section is then introduced in this thesis. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018

Today, conventional substation protection and control systems are of a widely distributed character. One substation can easily have as many as 50 data processing points that all perform similar algorithms on voltage and current data. There is also only limited communication between protection devices, and each device is only aware of the bay in which it is installed. With the intent of implementing a substation protection system that is simpler, more efficient and better suited for future challenges, Ellevio AB implemented a centralized system in a primary substation in 2015. It is comprised of five components that each handle one type of duty: Data processing, communication, voltage measurements, current measurements and breaker control. Since its implementation, the centralized system has been in parallel operation with the conventional, meaning that it performs station wide data acquisition, processing and communication, but is unable to trip the station breakers. The only active functionality of the centralized system is the voltage regulation. This work is an evaluation of the centralized system and studies its protection functionality, voltage regulation, fault response and output signal correlation with the conventional system. It was found that the centralized system required the implementation of a differential protection function and protection of the capacitor banks and busbar coupling to provide protection equivalent to that of the conventional system. The voltage regulation showed unsatisfactory long regulation time lengths, which could have been a result of low time resolution. The fault response and signal correlation were deemed satisfactory.

A utilização de energia solar fotovoltaica é amplamente difundida no mundo e possui caráter promissor no Brasil atualmente. Apesar do grande potencial brasileiro, esta fonte de energia ainda apresenta baixos níveis de utilização. A competitividade da geração fotovoltaica de grande porte em usinas solares fotovoltaicas ainda não atingiu patamares admissíveis com taxas de retorno financeiro atrativas ao mercado nacional. Por se tratar de uma fonte de energia renovável, sua utilização no cenário mundial tem apresentado crescimento nos últimos anos. Mesmo em países que apresentam potenciais solares inferiores aos do Brasil, esta fonte de energia tem se mostrado competitiva devido aos incentivos oferecidos. Tendo em vista este prisma, o presente trabalho busca apresentar possibilidades de inserção de usinas solares fotovoltaicas no Estado do Rio Grande do Sul. A usina proposta possui capacidade de geração de 30 MWp. Este estudo visa apresentar uma proposta de diversificar a geração de energia elétrica no estado do Rio Grande do Sul, apresentando uma nova alternativa de geração de energia renovável. Para tal realização, foram estudadas as linhas de transmissão e subestações existentes no estado do Rio Grande do Sul como forma de avaliar a possibilidade de conexão direta da nova usina, tendo como objetivo a redução do custo de instalação. Foi realizado o cálculo da produtividade fotovoltaica para o estado do Rio Grande do Sul e a análise dos custos de instalação desta fonte no Estado, bem como a relação de preço da geração centralizada no estado. / The use of photovoltaic solar energy is widespread in the world and has promising character in Brazil today. Despite the large Brazilian potential, this energy source still shows low levels of utilization. The competitiveness of photovoltaic generation in large solar photovoltaic power plants has not yet reached acceptable levels with attractive rates of financial return to the national market. Because it is a renewable source of energy, its use in the world has been increasing in recent years. Even in countries that have lower solar potential than Brazil, this source of energy has been competitive due to the incentives offered. Given this perspective, this paper seeks to show the possibilities for integration of photovoltaic solar plants in the state of Rio Grande do Sul. The proposed plant has a generation capacity of 30 MWp . This study aims to present a proposal to diversify the electricity generation in the state of Rio Grande do Sul, presenting a new alternative source of renewable energy . For this achievement, the existing transmission lines and substations were studied in the state of Rio Grande do Sul as a way to evaluate the possibility of direct connection of the new plant, with the objective of reducing the cost of installation. The calculation of photovoltaic productivity for the state of Rio Grande do Sul and cost analysis of installing this source was held as well the price ratio of centralized generation.

O objetivo deste trabalho foi desenvolver um sistema para atender as necessidades de controle e automação de um sistema de climatização para abrigos de equipamentos eletrônico, contemplando o controle dos níveis de umidade, de temperatura e a eliminação de partículas de poeira suspensa no ar. Existe uma ampla gama de tipos de abrigos, como subestações pré-fabricadas, data-centers, shelters de telecomunicação, salas elétricas, dentre outros. Ao abrigar equipamentos elétricos em funcionamento, a quantidade e acumulo de energia térmica no interior do ambiente onde se localizam ocasiona a elevação da temperatura a níveis inaceitáveis ao bom funcionamento dos equipamentos abrigados. Além disso, a umidade e a existência de particulados no ambiente podem causar a deterioração dos componentes eletrônicos. Por esse motivo é inevitável a utilização de um sistema de climatização para proteção desses equipamentos. O ato de refrigerar, desumidificar, purificar e renovar o ar permite o aumento da vida útil dos equipamentos instalados no interior desses abrigos. O projeto desenvolvido neste trabalho para automatização de um sistema de climatização foi aplicado a uma subestação elétrica pré-fabricada para uma indústria do ramo de mineração.Inicialmente realizou-se um estudo das exigências que o sistema de climatização teria que atender. Realizou-se uma modelagem do sistema levando-se em conta os requisitos do projeto e, para que o sistema fosse aplicado em campo, a lógica de programação foi testada em fábrica por meio do software de programação do CLP e posteriormente comissionado antes da entrega final em campo. O teste de campo consistiu em ligar o sistema automatizado de climatização e simular todo o funcionamento e condições de falhas possíveis, certificando que as respostas do sistema estivessem dentro das especificações definidas durante o projeto. O sistema desenvolvido encontra-se em funcionamento e serve de modelo para o desenvolvimento de novos projetos de climatização. / The aim of this study was to develop a system to attend the needs of automation and control of a cooling system for electronic equipment shelters, including the control of humidity, temperature and elimination of dust particles suspended in air. There is a wide range of types of shelters, such as prefabricated substations, data centers, telecom shelters, electrical rooms, among others. In house electrical equipment in operation, the amount and accumulation of heat inside this type o shelters where they are located causes the temperature rise to unacceptable levels for the proper functioning of equipment housed. Moreover, the presence of moisture and particulates in the environment may cause deterioration of electronic components and so it is inevitable to use a cooling system for protection of such equipment. The act of cooling, dehumidify, purify and renew the air permit to increase the lifetime of the equipment installed inside these shelters. The project developed in this work for automation of a cooling system was applied to an electrical substation for a prefab industry mining sector. Initially we carried out a study of the requirements that the HVAC system and would have to attend before the system was applied in the field, the programming logic was tested at the factory through the PLC programming software and subsequently commissioned before final delivery in field. The field test was to connect the automated climate control and simulate the entire operation and fault conditions possible, ensuring that the system responses were within the specifications established during the project. The system is designed for operation and serves as a model for the development of new draft cooling.

The aim of the thesis was minimize the planned cost of construction of the electricity network in North Africa and the Arabian peninsula between solar power plant in Desertec project. The work is divided into three chapters. The first chapter is devoted Desertec concept, its key technologies, benefits and barriers. Another chapter is devoted to the theory of graphs. It consists of an introduction to graph theory, minimum spanning tree and Steiner tree. The third practical chapter is devoted to reduction of the initial projected cost of constructing Electric Supply network using Steiner tree and its modifications. It also addresses the issue of valuation of edges and nodes to which it is necessary to include a number of factors such as energy capacity to be transmitted, the type of transmission medium, environmental conditions, geomorphological aspects and other safety regulatory requirements.

A utilização de energia solar fotovoltaica é amplamente difundida no mundo e possui caráter promissor no Brasil atualmente. Apesar do grande potencial brasileiro, esta fonte de energia ainda apresenta baixos níveis de utilização. A competitividade da geração fotovoltaica de grande porte em usinas solares fotovoltaicas ainda não atingiu patamares admissíveis com taxas de retorno financeiro atrativas ao mercado nacional. Por se tratar de uma fonte de energia renovável, sua utilização no cenário mundial tem apresentado crescimento nos últimos anos. Mesmo em países que apresentam potenciais solares inferiores aos do Brasil, esta fonte de energia tem se mostrado competitiva devido aos incentivos oferecidos. Tendo em vista este prisma, o presente trabalho busca apresentar possibilidades de inserção de usinas solares fotovoltaicas no Estado do Rio Grande do Sul. A usina proposta possui capacidade de geração de 30 MWp. Este estudo visa apresentar uma proposta de diversificar a geração de energia elétrica no estado do Rio Grande do Sul, apresentando uma nova alternativa de geração de energia renovável. Para tal realização, foram estudadas as linhas de transmissão e subestações existentes no estado do Rio Grande do Sul como forma de avaliar a possibilidade de conexão direta da nova usina, tendo como objetivo a redução do custo de instalação. Foi realizado o cálculo da produtividade fotovoltaica para o estado do Rio Grande do Sul e a análise dos custos de instalação desta fonte no Estado, bem como a relação de preço da geração centralizada no estado. / The use of photovoltaic solar energy is widespread in the world and has promising character in Brazil today. Despite the large Brazilian potential, this energy source still shows low levels of utilization. The competitiveness of photovoltaic generation in large solar photovoltaic power plants has not yet reached acceptable levels with attractive rates of financial return to the national market. Because it is a renewable source of energy, its use in the world has been increasing in recent years. Even in countries that have lower solar potential than Brazil, this source of energy has been competitive due to the incentives offered. Given this perspective, this paper seeks to show the possibilities for integration of photovoltaic solar plants in the state of Rio Grande do Sul. The proposed plant has a generation capacity of 30 MWp . This study aims to present a proposal to diversify the electricity generation in the state of Rio Grande do Sul, presenting a new alternative source of renewable energy . For this achievement, the existing transmission lines and substations were studied in the state of Rio Grande do Sul as a way to evaluate the possibility of direct connection of the new plant, with the objective of reducing the cost of installation. The calculation of photovoltaic productivity for the state of Rio Grande do Sul and cost analysis of installing this source was held as well the price ratio of centralized generation.