Time-domain Analysis of Multiconductor Transmission Lines Excited by Transient Electromagnetic Disturbances Based on the Analog Behavior Modeling

L'abstract è presente nell'allegato / the abstract is in the attachmen

Outdoor Insulation and Gas Insulated Switchgears

This book focuses on theoretical and practical developments in the performance of high-voltage transmission line against atmospheric pollution and icing. Modifications using suitable fillers are also pinpointed to improve silicone rubber insulation materials. Very fast transient overvoltage (VFTO) mitigation techniques, along with some suggestions for reliable partial discharge measurements under DC voltage stresses inside gas-insulated switchgears, are addressed. The application of an inductor-based filter for the protective performance of surge arresters against indirect lightning strikes is also discussed

AC Discharge Characteristics of Environmentally-Friendly Insulation Gases

This thesis proposes an investigation of trifluoroiodomethane (CF3I) gas mixture as an alternative eco-friendly insulation medium to sulphur hexafluoride (SF6) in GIL applications. The aim of the project is to model and test a reduced scale GIL under high alternating voltage environment

Simulation and optimization model for the construction of electrical substations

One of the most complex construction projects is electrical substations. An electrical substation is an auxiliary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Construction of electrical substation includes civil works and electromechanical works. The scope of civil works includes construction of several buildings/components divided into parallel and overlapped working phases that require variety of resources and are generally quite costly and consume a considerable amount of time. Therefore, construction of substations faces complicated time-cost-resource optimization problems. On another hand, the construction industry is turning out to be progressively competitive throughout the years, whereby the need to persistently discover approaches to enhance construction performance. To address the previously stated afflictions, this dissertation makes the underlying strides and introduces a simulation and optimization model for the execution processes of civil works for an electrical substation based on database excel file for input data entry. The input data include bill of quantities, maximum available resources, production rates, unit cost of resources and indirect cost. The model is built on Anylogic software using discrete event simulation method. The model is divided into three zones working in parallel to each other. Each zone includes a group of buildings related to the same construction area. Each zone-model describes the execution process schedule for each building in the zone, the time consumed, percentage of utilization of equipment and manpower crews, amount of materials consumed and total direct and indirect cost. The model is then optimized to mainly minimize the project duration using parameter variation experiment and genetic algorithm java code implemented using Anylogic platform. The model used allocated resource parameters as decision variables and available resources as constraints. The model is verified on real case studies in Egypt and sensitivity analysis studies are incorporated. The model is also validated using a real case study and proves its efficiency by attaining a reduction in model time units between simulation and optimization experiments of 10.25% and reduction in total cost of 4.7%. Also, by comparing the optimization results by the actual data of the case study, the model attains a reduction in time and cost by 13.6% and 6.3% respectively. An analysis to determine the effect of each resource on reduction in cost is also presented

The ATLAS TRT electronics

The ATLAS inner detector consists of three sub-systems: the pixel detector spanning the radius range 4cm-20cm, the semiconductor tracker at radii from 30 to 52 cm, and the transition radiation tracker (TRT), tracking from 56 to 107 cm. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift tubes (or straws) and of electron identification based on transition radiation from fibres or foils interleaved between the straws themselves. This paper describes the on and off detector electronics for the TRT as well as the TRT portion of the data acquisition (DAQ) system

Análise comparativa do desempenho das manobras de religamento monopolar e tripolar para eliminação de faltas monofásicas em linhas de transmissão

Orientador: Maria Cristina Dias TavaresDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: Um sistema de energia elétrica compreende geração, transmissão e distribuição de energia elétrica. As linhas de transmissão são usadas para transmitir energia elétrica a centros de carga distantes. O rápido crescimento dos sistemas de energia elétrica nas últimas décadas resultou em um grande aumento do número de linhas em operação e seu comprimento total. Para níveis de transmissão EHV (extra alta tensão), entre 90-95% de todas as falhas de linha envolvem apenas uma única fase. Destes, mais de 90% são temporários e podem ser compensados ??por três fases de religamento; Conseqüentemente, faltas fase-terra têm recebido a maior atenção em estudos de sistema. Este projeto analisa as entidades da linha de transmissão resultantes da eliminação de uma falta monofásica usando o SPAR (Auto-Reclusão Monofásica) e o religamento automático trifásico na linha de transmissão de 400 kV. O projeto analisa a influência de diferentes parâmetros do sistema, como nível de compensação, comprimento da linha e local da falta, juntamente com o método de mitigação. Para o estudo de simulação, PSCAD / EMTDC é selecionado como o software de simulaçãoAbstract: An electric power system comprises of generation, transmission and distribution of electric energy. Transmission lines are used to transmit electric power to distant large load centers. The rapid growth of electric power systems over the past few decades has resulted in a large increase of the number of lines in operation and their total length. For EHV (extra high voltage) transmission levels, between 90¿95% of all line faults involve only a single phase. Of these, more than 90% are temporary and can be cleared by three phase reclosing; consequently, phase-to-ground faults have received the most attention in system studies. This project analyzes the transmission line entities resulting from elimination of a single-phase fault by using the SPAR (Single-Phase Auto-Reclosing) and three-phase auto-reclosing on the 400 kV transmission line. The project analyzes the influence of different system parameters like compensation level, line length and fault location together with the mitigation method. For the simulation study, PSCAD/EMTDC is selected as the simulation softwareMestradoEnergia EletricaMestre em Engenharia ElétricaCAPE

Advances and Technologies in High Voltage Power Systems Operation, Control, Protection and Security

The electrical demands in several countries around the world are increasing due to the huge energy requirements of prosperous economies and the human activities of modern life. In order to economically transfer electrical powers from the generation side to the demand side, these powers need to be transferred at high-voltage levels through suitable transmission systems and power substations. To this end, high-voltage transmission systems and power substations are in demand. Actually, they are at the heart of interconnected power systems, in which any faults might lead to unsuitable consequences, abnormal operation situations, security issues, and even power cuts and blackouts. In order to cope with the ever-increasing operation and control complexity and security in interconnected high-voltage power systems, new architectures, concepts, algorithms, and procedures are essential. This book aims to encourage researchers to address the technical issues and research gaps in high-voltage transmission systems and power substations in modern energy systems

Protection system coordination using expert system

Die wissenschaftliche These dieser Dissertation besteht in der Kernaussage, dass die Implementierung eines Expertensystems zur wissensbasierten Koordination von Schutzsystemen möglich ist. Im Fokus dieser Dissertationsarbeit steht das Vorhaben, die Parameter von Schutzgeräten vorzuschlagen, zu koordinieren und zu optimieren. Dabei verfolgt diese Arbeit zwei Ziele: 1 - Die Sammlung von Expertenwissen in einer Schutzsystem-Wissensbasis. 2 - Die Wahl und Programmierung einer geeigneten Expertensystem-Architektur zu einem Prototypen für optimierte Schutzkoordination. Die Erfahrungen von Schutzexperten wurden gesammelt und ausgewertet, um schließlich zu koordinierten Einstellwerten für Schutzgeräte zu gelangen, die sowohl zum Schutz von einzelnen Betriebsmitteln (Sammelschienen, Generatoren, Motoren, Transformatoren, Reaktoren, und Übertragungsleitungen) als auch des gesamten Hochspannungs- und Energiesystems beitragen. Dabei wenden Schutzexperten ihre Erfahrungen und ihr Wissen an, um Schritt für Schritt eine entsprechende Schutzkoordination vorzunehmen. Das Expertensystem imitiert dieses Verhalten in einer webbasierten Anwendung. Diese Arbeit unterteilt das zur Verfügung gestellte Wissen der Schutzexperten in kleinere Einheiten, nämlich in ein umfassendes Regelwerk für Schutzeinstellungen. Jede Regel kommt nur unter bestimmten Voraussetzungen zum Tragen. Infolgedessen erfragt das Expertensystem vom Anwender die jeweiligen Bedingungen, unter denen eine bestimmte Regel zur Anwendung kommt. Jeder Benutzerdialog besteht dabei aus den Bestandteilen: Frage, Antwort, Kriterien, Empfehlung und Optimierung. Die Reihenfolge, in der die Dialoge ablaufen bzw. in der die Fragen gestellt und Empfehlungen gegeben werden entspricht der Vorgehensweise von Schutzexperten gemäß den von ihnen zur Verfügung gestellten Erfahrungswerten. Aus jedem Dialog resultiert entweder ein bestimmter Einstellungswert oder ein bestimmtes Kriterium für die Einstellung eines Parameters einer jeden Schutzfunktion zu jedem Schutzgerät. Die generierten Einstellkriterien werden dann hinsichtlich der kürzesten Fehlerklärungszeiten oder der längsten Betriebsdauer einzelner Betriebsmittel und des Gesamtsystems optimiert. In jedem Dialog kann der Anwender die empfohlenen Werte übernehmen oder seine eigenen Einstellwerte vorgeben.  The scientific thesis of this dissertation is to move that implementing an Expert Systemfor protection system coordination knowledge domain is possible. This dissertation focuses on proposing, coordinating and optimizing protection devices setting values. This work has two main goals: 1- Expert engineers knowledge acquisition in protection system coordination domain. 2- Selecting a proper Expert System architecture and implementing it as a pilot system to optimize protection system coordination. We have collected the knowledge of experienced protection engineers which provides a coordinated protection settings for the protection of equipments (Bus, Generator, Motor, Transformer, Reactor and Line) and power systems. Experienced engineers apply their know-how step-by-step to carry out the protection coordination task. The Expert System imitates this behavior of expert engineers in a web-based application. This work has decomposed the protection knowledge of experts into smaller elements: the setting rules. Each setting rule is valid for definite conditions. Therefore, a sequence of dialogs is asked from the Expert System user to fulfill the required validity condition of each rule. Each dialog contains the following parts: Question, Answer, Criteria, Recommendation and Optimization. The sequence of which dialogs are asked as well as the question and the recommendation part of each dialog designed are based on the know-how knowledge of the expert engineers. Each dialog recommends either a setting value or a setting criterion for each parameter of each protection function in each protection device. The generated setting criteria are optimized to provide the shortest fault clearing time or the longest equipment or system operation time. In each dialog, the Expert System user may accept the proposed recommendation or dictate his proposed value