Transmissão de potência em corrente contínua e em corrente alternada: estudo comparativo

This paper presents a comparative study based on literature and examples in the literature, the two main technologies for the transmission of electricity at high voltage: alternate current transmission and direct current transmission. Inside the direct current transmission will be shown two technologies currently employed, transmission by current source and transmission by voltage source, contributing to a better understanding of them. The ultimate goal is to provide a text for consultation to identify key characteristics that influence the choice of future transmission lines

Análise do consumo de energia elétrica e da eficiência energética em uma indústria de processamento de madeira

In the industries of wood processing (sawmills), where timber is sawn in equipment such as band saws, circular saws, trowel, thicknessers, among others, that mechanically transform this resource and use of electric motors, which are not unusually poorly scaled working or overloaded, often a factor that is not found in these industries and has fundamental importance in the production process is energy efficiency that is achieved by both technological innovation and through all the practices and policies that aim to lower energy consumption, lowering energy costs and increasing the amount of energy offered no change in generation. For both during the design of an electrical installation, both overall and in various sectors of the installation, investigations are necessary, considerations and uses of variables and factors that put into practice the theme of energy efficiency. Therefore, in this paper, these factors were calculated and analyzed for a wood processing industry (sawmill) in the municipality of Taquarivaí - SP, namely: active power, power factor, demand factor and load factor. Where they were small in relation to the literature, these events that occur when devices are connected at the same time and due to the conditions of processing the wood, where the engines have large variations in electricity consumption during the unfolding of the same, due to efforts with the load and idle moments between each machining operation in the equipment

Localização de descargas parciais em transformadores de potência imersos em óleo mineral por meio de cápsulas piezelétricas de baixo custo e sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Elementos de manutenção de transformadores de potência

The intended purpose of this paper is to present the main commissioning tests for power transformers and the most used techniques in industrial segment, it is also discussed your results and consequences in the equipment’s normal operation. Also in this text, it is given specific information concerning a maintenance plan compatible to power transformers, with elements of preventive and predictive maintenance, exposing essential components, tests and the regulations current, showing how analyze and interpreted the results from this maintenance resources. Also in this paper is submitted the economic impact of damage to transformers and how the correct maintenance method can minimize them. The objective of this text is demonstrate the importance of the equipment and the benefits of proper maintenance, much of in financial terms as in electric system reliability

Sistema de gerenciamento de energia para controle de carga/descarga entre baterias de lítio e ultracapacitores, envolvendo sistema de tração elétrica com frenagem regenerativa

Pós-graduação em Engenharia Elétrica - FEIS

Planejamento de reativos em sistemas elétricos de potência multi-área através de modelos estocásticos

Pós-graduação em Engenharia Elétrica - FEIS

Alocação ótima de chaves de interconexão nas redes de distribuição de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Alocação ótima de equipamentos SVC e TCSC na rede de transmissão de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Modelo matemático para o controle ótimo de Volt/VAr em sistemas de distribuição de energia elétrica trifásicos

Pós-graduação em Engenharia Elétrica - FEIS

Desenvolvimento de um sistema de gerenciamento de energia (EMS - Energy Management System) para a rede elétrica inteligente (Smart Grid)

Pós-graduação em Engenharia Elétrica - FEIS

Modelação de redes de distribuição de energia elétrica com carregamento não linear, incluindo elementos de regulação e compensação

Pós-graduação em Engenharia Elétrica - FEIS

Simulação em tempo real de sistemas de distribuição de energia elétrica utilizando-se estruturas com descrição de hardware em software

Pós-graduação em Engenharia Elétrica - FEIS

Sistema de geração e armazenamento de energia elétrica utilizando transdutor piezelétrico na forma pulsada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação da teoria de potência conservativa para monitoramento do comportamento do motor de indução trifásico sob distúrbios de qualidade de energia

Pós-graduação em Engenharia Elétrica - FEB

Retificador entrelaçado com elevado fator de potência para operação de um veículo trólebus alimentado por redes em CA Ou CC

This paper presents the development and the main results for an interleaved boost rectifier operating as a special input power stage for a trolleybus type vehicle, allowing its feeding by alternate current (AC) or direct current (DC) distribution power systems. When feeding with two wires (single phase) alternate current distribution system, the converter accomplish active power factor correction, providing a relatively sinusoidal current with low total harmonic distortion (THD) and fully complying with IEC 61000-3-4 standards. In addition, a management control system promotes the required automatic operation changes for the proposed rectifier when the vehicle is changing from the DC distribution power system to the AC distribution power system and vice-versa, keeping its original electrical DC system characteristics for the adjustable speed driver sub-system. The main experimental results for a prototype rated at 150kW are presented, considering its application for a trolleybus with DC adjustable speed driver, demonstrating the proposed converter benefits and the possibility of AC feeding system for trolleybus type vehicle.