Anteprojeto de um sistema digital de proteção e controle aplicado em uma subestação elétrica industrial

With the growth of the demand on electric energy in the last decades, the urban distribution and transmission systems have experienced a bigger necessity to improve on the substations, the automation procedures and techniques on the operation maneuvers of such systems, in a sense that better attends the quality levels, availability, continuity and operational reliability. In this way, the objective of the present paper is to perform a study of protection and control on an electrical industrial system involving the procedures of digitizing and maneuvers automatism utilizing operational techniques and other pertinent information used in a typical high-voltage Industrial Electrical System. Analysis were made on short-circuits to specify the main components of the 138 [kV] substation, in addition, there were used digital MiCOM relays to make the protection of the present elements. With that, a program was developed to allow the user to monitor the condition of circuit-breakers through a supervision screen being able to simulate some kinds of faults, as well as observing the characteristics of each device. This way, the importance of having a fast and reliable system that ensures the equipment’s protection and the industrial process continuity due to faults on the electrical system is noticeable. It’s important to highlight that all this digitizing was mainly favored by the development of digital technology on the last years, mainly on microelectronics, also with the appearance of supervision gadgets allowing the development of complex systems in supervision and electric energy control

A influência da temperatura nas impedâncias de sequência de condutores utilizados na rede primária de distribuição

Distribution networks are formed by long lines that carry electricity substations to homes and industries. These lines have associated impedance and depending on operating conditions of the network these impedances may vary. This paper provides a detailed analysis of the effects observed in studies of voltage drop, short circuit and electrical losses, when considered the drivers sequence impedances used in primary distribution network at different temperatures. Therefore, it is initially presented a calculation methodology and details the factors that influence the final values. The methodology presented tackles in a practical way the main factors that directly or indirectly influence the values of the impedances as an emblematic example and will be properly dealt with throughout the paper is the effect of temperature on the values of the sequence impedances. More specifically is dealt with the case of XLPE cables protected, by having a higher maximum operating temperature than the operating temperature of the network. The effects observed in the power flow generated when considering the impedance values at both temperatures were analyzed. The impedance drivers tend to increase with increasing temperature. Thus the impedance of the conductor XLPE protected will tend to be greater for the maximum operating temperature for which the operating temperature of the network, resulting in greater voltage drop and higher electrical losses

Efeito de protocolos de cimentação na carga de fratura para uma cerâmica de dissilicato de lítio

Pós-graduação em Odontologia Restauradora - ICT

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

Pós-graduação em Engenharia Elétrica - FEIS

Influência do exercício prévio pesado na performance aeróbia de curta duração realizada com diferentes estratégias de distribuição da intensidade em indivíduos treinados e não treinados no ciclismo

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

Determinação do tempo de vida de restaurações totalmente cerâmicas (y-tzp/porcelana) com incidência da carga em diferentes regiões de contato

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

Pós-graduação em Engenharia Elétrica - FEIS

Aplicação de técnicas metaheurísticas para resolver o problema de coordenação de carregamento de veículos elétricos em sistemas de distribuição

Pós-graduação em Engenharia Elétrica - FEIS

Compensador série controlado a tiristores na distribuição: Compensação dinâmica

Pós-graduação em Engenharia Elétrica - FEIS

Reconfiguração de sistemas de distribuição operando em vários níveis de demanda através de uma meta-heurística de busca em vizinhança variável

Pós-graduação em Engenharia Elétrica - FEIS

Adaptação e instrumentação de um esqui ergométrico para pessoas com deficiência motora dos membros inferiores

Pós-graduação em Engenharia Elétrica - FEIS

O impacto do preparo, da cerâmica e do contato oclusal na distribuição de tensões em facetas

Pós-graduação em Odontologia Restauradora - ICT

Análise do impacto de sistemas fotovoltaicos conectados à rede de distribuição na qualidade da energia de uma smart city: Análise do impacto de sistemas fotovoltaicos conectados à rede de distribuição na qualidade da energia de uma smart city

Pós-graduação em Engenharia Elétrica - FEIS

Influência da angulação do implante e tipo de intermediário na distribuição das tensões

The aim of this study was to evaluate the influence of implant angulation and abutment type (UCLA and Estheticone) on stress distribution in screw-retained implant-supported prostheses through photoelasticity. Three models were fabricated with photoelastic resin PL-2 (Vishay, Micro-Measurements Group, Inc Raleigh, N.C., USA) containing one external hexagon implant with 3.75x10mm (Master screw, Conexão Sistemas de Prótese Ltda., Arujá, São Paulo) with 0°, 17° and 30° degrees and a screw-retained prostheses with UCLA and Estheticone abutments. The assembly was positioned in a circular polariscope; axial and oblique (45° degrees) loads of 100N were applied in fixed points on the occlusal crown surfaces by a universal testing machine. The stress generated was photographed and analyzed qualitatively with appropriate software (Adobe Photoshop®). The results demonstrated the same number of fringes for both abutment types for each angulation, with fringes increasing in the same way. A higher number of fringes were closer in the oblique loading mode. It was concluded that there was no significant difference in stress distribution in prostheses with UCLA and Estheticone abutments. Higher stress concentrations were observed with increased implant angulation. Stress concentration and intensity were higher in the oblique load than in axial load application.

Adição de plasma bovino em salmouras para injeção de coxão duro bovino (m. Biceps femoris) e seus efeitos no pH e na carga microbiana de bifes cozidos embalados à vácuo e mantidos sob refrigeração

The physical (pH) and microbiological (psychotrofi c microorganisms and lactic bacteria) characteristics of beef outside round (m. Biceps femoris) injected (15%) with brines free of polyphosphates containing and sodium lactate or sodium lactate and sodium diacetate and liquid bovine plasma (PLL and PLO) or dehydrated bovine plasma (PDL, PDO) were evaluated along with beef cuts injected with brines free from plasma, but containing polyphosphates and bacteriostatic agents (CL and CO) and non injected beef cuts (IN), comprising seven treatments of cooked and vacuum packaged beef steaks stored under refrigeration (6ºC) during 43 days. No differences in pH were detected among raw or cooked injected treatments, although IN showed lower pH value in raw beef cuts. The addition of liquid or dehydrated bovine plasma did not affect the microbial load after whole muscles pasteurization, but increased the bacterial counts in cooked beef steaks during refrigerated storage, comparing to treatments with no plasma addition (CL and CO). The storage temperature (6ºC), usually found during commercialization of meat increased the microorganisms growth rate affecting the microbiological quality, especially when plasma was added to the brine.