Convergence Property of the Measurement Gross Error Correction in Power System State Estimation, Using Geometrical Background

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Multi-Stage Stochastic Non-Linear Model for Reactive Power Planning Under Contingencies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento dinâmico não-linear em fenômenos de colheita de energia usando dispositivos baseados em materiais piezoelétricos em estruturas aporticadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Energetic and economic analysis of a Brazilian compact cogeneration system: Comparison between natural gas and biogas

Cogeneration may be defined as the simultaneous production of electric power and useful heat from the burning of a single fuel. This technique of combined heat and power production has been applied in both the industrial and tertiary sectors. It has been mainly used because of its overall efficiency, and the guarantee of electricity with a low level of environmental impact. The compact cogeneration systems using internal combustion engine as prime movers are thoroughly applied because of the good relationship among cost and benefit obtained in such devices. The cogeneration system of this study consists of an internal combustion engine using natural gas or biogas as fuel, combined with two heat exchangers and an absorption chiller utilising water-ammonia as working mixture. This work presents an energetic and economic comparison between natural gas and biogas as fuel used for the system proposed. The results are useful to identify the feasible applications for this system, such as residential sector in isolated areas, hotels, universities etc. (C) 2014 Elsevier Ltd. All rights reserved.

Transmission Expansion Planning Via a Constructive Heuristic Algorithm in Restructured Electricity Industry

The transmission expansion planning problem in modern power systems is a large-scale, mixed-integer, nonlinear and non-convex problem. this paper presents a new mathematical model and a constructive heuristic algorithm (CHA) for solving transmission expansion planning problem under new environment of electricity restructuring. CHA finds an acceptable solution in an iterative process, where in each step a circuit is chosen using a sensitivity index and added to the system. The proposed model consider multiple generation scenarios therefore the methodology finds high quality solution in which it allows the power system operate adequacy in an environment with multiple generators scenarios. Case studies and simulation results using test systems show possibility of using Constructive heuristic algorithm in an open access system.

Congestion Effects on Regional & System Emission and Consumers Allocated Cost

This paper considers the congestion effects on emission and consumers' allocated cost. In order to consider some environmental and operational effects of congestion, an environmental constrained active-reactive optimal power flow (AROPF) considering capability curve is presented. On outage conditions, the total cost of the system will increase. On the other hand in power systems, the operating cost and system emission have conflicted objectives, then it may be concluded that the outage in the system may lead to a total emission decrease. In this paper the famous Aumann-Shapley method is used as a pricing methodology. Two case studies such as 14-bus and US-bus IEEE test systems are conducted. Results demonstrate that, although the line outage in power systems leads to increase the total cost, the amount of emission depending on the place where the outage occurs can be more than, less than or equal to the normal conditions' emission. Also results show that although from power sellers' standpoint the well-known Aumann-Shapley method is a precise pricing method to cover the incurred cost with an acceptable error that can show the real effect of congestion on consumers' cost, from consumers' standpoint it is not a good method for cost allocation, because some consumers will face with an increase in cost and the others will face with a decrease on their cost.

Estudo e analise dos sistemas de proteção em subestações automatizadas de energia elétrica

Electrical energy is present in the lives of all people and is extremely important that it be delivered to end users with plenty of quality, safety and low costs. The electric power substations are responsible for transmission and distribution of electricity generating sources to consumers, and with technological advances and the subsequent automation of same, the electricity began to be delivered with greater continuity and reliability. Protection systems in substations are largely responsible for making the electricity reaches the final consumer with quality, since their function is to prevent the spread of any type of failure occurred at any point of transmission to the load centers. These systems consist primarily by the current transformers and potential, by the protective relays and circuit breakers and switchgear. The processors send the necessary data to the relays and, if those detect any abnormality in the system, operate the opening command of the branch circuit breakers to isolate where the fault. Therefore, it is essential to better understand the operation of such equipment, as well as the overall system. This work aims to study the main substation equipment, current transformers and potential and, especially, protection relays, in order to obtain the advantages that automated systems can provide

Análise de desempenho de lâmpadas LEDs e LFCs como alternativas em iluminação residencial em função da implementação da portaria ministerial n° 1007 que limita o uso de lâmpadas incandescentes no Brasil

With the imposition of the suspension of production and subsequent banning of incandescent light bulbs will be necessary to replace it by other more energy-efficient. Although the main alternative is the compact fluorescent lamp, the environmental impact caused by it due to incorrect disposal and the amount of harmonics included in the network resulting in losses related to the quality of electric power system makes them sought new alternatives for lighting systems that are efficient and have low environmental impact. In this context, the LED (Lighting Emitting Diode), based on solid-state components, is presented as an option for new projects and replacement of existing lighting. In this work we studied aspects of energy, environmental and economic impacts of a possible replacement of conventional lighting systems for new technology. From laboratory tests and surveys of the costs of different types of lamps used for residential lighting, we performed a comparative analysis considering energy and economic aspects which showed that the LED technology, but has a high initial investment, it is best when power quality and environmental preservation are relevant factors in decision making for the choice of technology to be used in the lighting system

Projeto e implantação de pequena central de geração hidrelétrica: análise de caso

The objective of this work is to study the implantation feasibility of a small hydropower system in a rural area in Guaratinguetá. Due to its location and accessibility, and the costs involved in extending the public distribution line to the property it could turn become viable the construction of an individual electric generation system. As alternatives, a solar photovoltaic system and combustion engine-electric generator systems were considered. However, the existence of a small river inside the property, the construction of a micro hydropower plant was taken into account. The choice of the micro power hydropower plant was determined by the owner and was based on the costs. The topographic and hydrological profiles as well as the geometrical characteristics of the system, including the civil infrastructure needed and the more adequate turbine, were determined. Finally, the cost spreadsheet was set and the results were compared with those calculated for the extension of the available public distribution system

Estudo das principais políticas para melhoria da eficiência energética no setor elétrico

This paper aims at comparing the national and international incentive policies in energy efficiency investment and presenting the main trends, measures adopted and economical and environmental results obtained, as well as possible improvements and expansions of these programs. This analysis is justified by the current moment, not only of the Brazilian Power Systems (SEB) but also of the global power systems with the constant increase of demand and depletion of natural resources implying in a need of a better use of them and of the power they generate, which directly affects the losses on the generation, transmission, distribution and consumption of energy, in addition to reducing the impacts on the environment. At last but not least, through this study it was possible to gleam not only at new possible ways for these programs, but also failures and inefficiencies that can be improved in the measures currently being used

Localização e preço de contrato ótimo da geração distribuída em sistemas de distribuição radiais de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Alocação de bancos de capacitores em sistemas de distribuição radiais usando busca dispersa

Pós-graduação em Engenharia Elétrica - FEIS

Heurística especializada aplicada na alocação ótima de bancos de capacitores em sistemas de distribuição radial

Pós-graduação em Engenharia Elétrica - FEIS

Viabilidade técnica e econômica do uso da energia solar térmica em condomínios horizontais com habitações populares

Pós-graduação em Engenharia Mecânica - FEG

Transmissão indutiva de energia eletromagnética sem fios, para aplicações em postos de abastecimento de veículos elétricos puros: modelação para o elemento eletromagnético

Pós-graduação em Engenharia Elétrica - FEIS