Developing accurate construction estimates is critical for electric utilities to make reliable financial plans for their future. Parametric estimating is just one of several techniques available to help estimate the cost of a construction project. Other estimating methods may have some advantages over parametric estimating in the latter stages of a project but parametric estimating is possibly the most accurate method in the very early stages of a project. This report delves into the analysis and development of a parametric equation for use primarily in the very early stages of a construction project. The result of this research is a functional equation that can be used for estimating future electric substation construction cost with a fair level of confidence. / text

Em virtude da grande proporção das falhas humanas em relação ao número total de falhas, dos gargalos de fornecimento de energia elétrica e do histórico de falhas humanas ocorridas nos últimos anos no sistema elétrico brasileiro, a análise da confiabilidade humana é relevante para o setor elétrico para o aumento da confiabilidade e mitigação da ocorrência de corte de fornecimento de energia aos consumidores. Nesse contexto, esse trabalho objetiva aplicar uma metodologia existente para analisar a probabilidade de ocorrência de falha humana em uma subestação de energia elétrica. Aborda o assunto inicialmente revisando a evolução do cenário de falhas humanas, desde o período da Guerra Fria (1945 a 1989), quando se realizaram os primeiros estudos, até o atual momento, para contextualizar a necessidade de atualização dos conhecimentos sobre confiabilidade humana. No referencial teórico, compilaram-se as conceituações dos diversos métodos utilizados para realização da análise da confiabilidade humana e os fatores que exercem influência sobre o desempenho do operador na execução das tarefas. Elaborou-se uma tabela com o objetivo de propiciar a comparação entre os diversos métodos com suas vantagens e desvantagens. Na sequência, faz-se a apresentação da metodologia para análise da confiabilidade humana, com a definição do cenário crítico, análise dos fatores que exercem influência sobre o desempenho dos operadores e estruturação e análise da árvore de decisão holística com os possíveis valores de probabilidade de ocorrência de erros humanos. Os resultados de sua aplicação em uma subestação do setor elétrico localizada no Estado de Mato Grosso indicaram um valor inicial de probabilidade de ocorrência de erro humano para o cenário analisado. O resultado da pesquisa demonstra qualitativa e quantitativamente quais fatores exerceram mais influência sobre o desempenho humano para esse cenário. Verificou-se que ações para melhoria dos níveis de qualidade dos fatores de desempenho avaliados negativamente, reduzem significativamente a probabilidade de ocorrência de erro humano. Com a determinação da probabilidade de erro humano e dos fatores que exercem influência sobre o operador para sua ocorrência, esta metodologia poderá ser aplicada como ferramenta adicional de gestão do processo de prevenção de falhas humanas e aumento da confiabilidade do setor elétrico. / Due to the large proportion of human failures in relation to the total number of failures, the restrictions in the supply of electric power and the history of human failures in recent years in the Brazilian electricity system, human reliability is relevant for the electric sector to increase the reliability and mitigation of the occurrence of power outages to consumers. In this context, this work aims to apply an existing methodology to analyze a probability of occurrence of human failure in an electric power substation. It addresses the subject initially by reviewing the evolution of the scenario of human failings, from the period of the Cold War (1945 to 1989), when the first studies were carried out, to date, to contextualize the need to update knowledge about human reliability. The theoretical framework supported the compile the concepts of the various methods used to perform the human reliability analysis and the factors that influence the performance of the operator in the execution of the tasks. A table that compares the more relevant methods presents the advantages and disadvantages of each one. Afterwards, the methodology for analysis of human reliability is presented, with the definition of the critical scenario, analysis of the factors that influence the performance of the operators, and the structuring and analysis of the holistic decision tree with the possible probability of occurrence of human errors. The results of its application in a substation of the electric sector located in the State of Mato Grosso indicated an initial probability of occurrence of human error for the analyzed scenario. The results of the research demonstrate qualitatively and quantitatively which are the factors that exerted the most influence on human performance for the scenario. Actions to improve the quality levels of the performance factors evaluated negatively reduce significantly the probability of occurrence of human error. With the determination of the probability of human error and which are the factors that influence the operator for its occurrence, this methodology can be an additional tool to manage the process of human error prevention and increase the reliability of the electric power system.

In recent years, reliability evaluation of substation automation systems has received a significant attention from the research community. With the advent of the concept of smart grid, there is a growing trend to integrate more computation and communication technology into power systems. This thesis focuses on the reliability evaluation of modern substation automation systems. Such systems include both physical devices (current carrying) such as lines, circuit breakers, and transformers, as well as cyber devices (Ethernet switches, intelligent electronic devices, and cables) and belong to a broader class of cyber-physical systems. We assume that the substation utilizes IEC 61850 standard, which is a dominant standard for substation automation. Focusing on IEC 61850 standard, we discuss the failure modes and analyze their effects on the system. We utilize reliability block diagrams for analyzing the reliability of substation components (bay units) and then use the state space approach to study the effects at the substation level. Case study is based on an actual IEC 61850 substation automation system, with different network topologies consideration concluded. Our analysis provides a starting point for evaluating the reliability of the substation and the effects of substation failures to the rest of the power system. By using the state space methods, the steady state probability of each failure effects were calculated in different bay units. These probabilities can be further used in the modeling of the composite power system to analyze the loss of load probabilities.

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Abstract: This report covers primarily the work of documenting electromagnetic fields generated by one of the later parts in the electrical power distribution chain: The electrical substation, wherein 10 kV is transformed to 400 V for use by private consumers. Thus it is one of the most widespread and frequently occurring parts in the Swedish power grid and of particular interest, as electrical substations are found everywhere in populated areas, often in close vicinity to people and animals. The report deals with a number of formulated questions and/or hypothesis’ stated at the onset of the work undertaken, theory that is relevant for the topics the report covers, the details of the field work undertaken and the following analysis of the readings, which in term provide answers for the questions stated in the beginning. It also covers what is the currently known short term and long term risks associated with electromagnetic fields in the power frequent spectrum and of varying intensity in the vicinity of humans. The analysis also provides recommendations and identifies several points to carefully consider when planning for new installations or replacements of some parts of existing installations. For enhanced reading comprehension there is, aside from sections with pictures and attached explanatory texts and templates, several graphs, one-line diagram and maps of the power grid among the appendixes to the rapport.

Minimization of Construction Costs of Substation Grounding Grids: In every electrical installation, one of the most important aspects is adequate grounding; in particular, the grounding of high-voltage substations to protect people and equipment in the event of an electrical fault. Well-designed grounding systems ensure the performance of power systems and safety of personnel. It is desirable that the substation grounding provides a near zero resistance to remote earth. The prevailing practice of most utilities is to install a grid of horizontal ground electrodes (buried bare copper conductors) supplemented by a number of vertical ground rods connected to the grid, and by a number of equipment grounding mats and interconnecting cables. The grounding grid provides a common ground for the electrical equipment and for all metallic structures at the station. It also limits the surface potential gradient. Currently the IEEE 80-2000 standard for substations grounding limits the determination of the grounding parameters (namely step, touch and ground potential rise) to that of a uniform soil model unless the Sunde graphical method is used. With the Sunde graphical method, it relies on interpretation to obtain a two layer soil model. Without the use of the graphical method, the IEEE 81-1983 has several empirical equations that can be used for the two layer model; however, these equations rely on the use of images which retard the speed of calculations to the point where the overall optimization of the grounding grid (with respect to size and shape) has yet to be determined. The goal of the thesis was to improve upon the current restrictions for the grounding grid design, while minimizing the material (i.e., copper conductors) and installation costs of a grid. The first part of the research examined previous work through a combination of literature review, mathematical computations, and field measurements to validate the theoretical aspects of grid design. The thesis introduces an optimized uniform and two-layer soil with fast accurate calculations directly from soil measurements without the use of graphical methods or the use of complex image theory. Next, the thesis develops enhanced grounding parameter equations using Simpson’s Rule of integration. The final part of the thesis demonstrates how it is possible to optimize the configuration of the grounding grid itself, minimizing costs, and yet still achieving a safe installation. This is the first time such an optimization is possible, and it is made possible by the techniques developed in this thesis. The techniques are applied to existing real-world grid designs, and the results obtained show the effectiveness of the method in reducing construction costs. This thesis shows how these construction and material savings are realized by utilizing a process whereby the grounding design minimizes the overall cost. The overall contribution of this thesis is the optimization of the grounding grid design by eliminating the current restrictions found in the IEEE standards 80 and 81, respectively, and offering an optimized grounding system design, starting from the soil model to the actual grounding design itself.

Society depends on computer networks for communication. The networks were built to support and facilitate several important applications such as email, web browsing and instant messaging. Recently, there is a significant interest in leveraging modern local and wide area communication networks for improving reliability and performance in critical infrastructures. Emerging critical infrastructure applications, such as smart grid, require a certain degree of reliability and Quality of Service (QoS). Supporting these applications requires network protocols that enable delay sensitive packet delivery and packet prioritization. However, most of the traditional networks are designed to provide best effort service without any support for QoS. The protocols used in these networks do not support packet prioritization, delay requirements and reliability. In this thesis, we focus on the design and analysis of communication protocols for supporting smart grid applications. In particular, we focus on the Substation Automation Systems (SAS). Substations are nodes in the smart grid infrastructure that help the in transportation of power by connecting the transmission and distribution lines. The SAS applications are con figured to operate with minimal human intervention. The SAS monitors the line loads continuously. If the load values are too high and can lead to damage, the SAS declares those conditions as faults. On fault detection, the SAS must take care of the communication with the relay to open the circuit to prevent any damage. These messages are of high priority and require reliable, delay sensitive delivery. There is a threshold for the delay of these messages, and a slight increase in the delay above the threshold might cause severe damages. Along with such high priority messages, the SAS has a lot of background traffic as well. In spite of the background traffic, the substation network must take care of delivering the priority messages on time. Hence, the network plays a vital role in the operation of the substation. Networks designed for such applications should be analyzed carefully to make sure that the requirements are met properly. We analyzed and compared the performance of the SAS under di erent network topologies. By observing the characteristics of the existing architectures, we came up with new architectures that perform better. We have suggested several modi cations to existing solutions that allow significant improvement in the performance of the existing solutions.

The objective of this thesis is to enhance the efficiency of Mass Rapid Transit (MRT) system and improve the power quality by reducing harmonic distortion. The energy consumption of an MRT system by considering the annual ridership and the stochastic operation characteristics of train sets are used to find the optimal placement of traction substations to enhance the operation efficiency of MRT systems. To mitigate the harmonic distortion, the installation location and capacity of harmonic filters are designed and verified by computer simulation. The software programs for AC/DC load flow study and harmonic distortion analysis have been developed and integrated to perform power system simulation of MRT operation. The mathematical model of 12-pulse uncontrolled rectifiers without interphase transformers is derived and implemented in the programs to obtain more accurate simulation results. The optimal inverter substation planning is solved by minimizing the overall cost of power consumption and inverter investment for mass rapid transit power systems with immune algorithm. The objective function and constraints are expressed as antigen, and all feasible solutions are expressed as antibody. The diversity of antibody is then enhanced by proximity of antigen so that the global optimization during the solution process can be obtained. It is found that the energy regeneration can be restored effectively with the optimal planning of inverters by the proposed immune algorithm. Based on the computer simulation of Taipei MRT system, the voltage harmonic distortion is varied dramatically with the dynamic load behavior of train sets. The stochastic harmonic load flow analysis is performed to investigate the power quality problem for an electrified rapid transit system. Different strategies of harmonic distortion mitigation have been proposed by minimizing the objective function to solve the optimal sizes and locations of harmonic filters so that the harmonic distortion can be reduced and reactive power compensation can be obtained at the same time. By performing the immune algorithm, the harmonic filters with proper capacity and the corresponding switching time for filter commitment are determined. It is found that the harmonic distortion can be effectively reduced for the MRT system by the proper design of harmonic filters.

Mass Rapid Transit(MRT) plays a very important role for the city development,the investment cost is very expensive. It is necessary to derive the MRT system planning by considering the service reliability and performance index according to the forecast of annual ridership. With the less ridership as compared to Taipei MRT network, Kaohsiung MRT has to be developed to achieve the most cost effective investment of power supply and rolling stock planning. This thesis is to investigate the proper expansion planning of traction substations (TSS) for an electrified mass rapid transit system. The motion equation of train sets is used to solve the mechanical power consumption at each time snapshot according to the operation timetable, the passenger ridership and various types of operation resistance. The mathematical models of power converters in traction substations for different operation modes have been derived. With all train sets operated along the main line, the AC/DC load flow analysis is performed to find power demand of all traction substations for annual system peak operation over the study period. The objective function is formulated by considering both the voltage drop of train sets and investment cost of traction substations as the equivalent cost of all feasible states of each year. By performing the dynamic programming (DP) and immune algorithm (IA), the expansion planning of traction substations to achieve the minimum overall cost has been solved by identifying the optimal capacity and locations of new traction substations to be committed at each year.

Circuit breakers are used in the power system to break or make current flow through power apparatus. Reliable operation of circuit breakers is critical to the well- being of the power system and can be achieved by regular inspection and maintenance. A low-cost automated circuit breaker monitoring system is developed to monitor circuit breaker control signals. An interface is designed on top of which different local and system-wide applications can be developed which utilize the data recorded by the system. Some of the possible applications are proposed. Lab and field evaluation of the designed system is performed and results are presented.