Magnetic Losses
Mostrando 25-36 de 49 artigos, teses e dissertações.
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25. Estimativas de perdas em estruturas saturadas
Esta dissertaÃÃo propÃe um modelo para a estimaÃÃo de perdas em estruturas magnÃticas que operam sob regime de intensa induÃÃo magnÃtica, tais como se verifica no reator com saturaÃÃo natural. A metodologia utilizada para elaboraÃÃo desse modelo fundamenta-se na clÃssica separaÃÃo das perdas em parcelas devidas a histerese e as correntes de F
Publicado em: 2008
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26. Metodologia para prognosticar a reducao de temperatura do enrolamento de campo de um hidrogerador
The medium and large hydrogenerators are tailor-made in a few identical units for each particular hydroelectric power plant. So, it is not expected that we can find identical generators in different power plants. Because these hydrogenerators are not previously tested, they only present design or erecting problems during the field acceptance tests or in the
Publicado em: 2008
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27. Determinação dos parâmetros de compensadores estáticos de reativos e estratégia para o projeto otimizado de reatores saturados
Due to the increasing demand of consumption, the electric energy systems have faced, in the current times, problems with its operation, being the voltage control one of the most relevant matters. To provide means to solve such problems, the use of static compensators has emerged, amongst others, as a classical alternative. Although the modern solutions are m
Publicado em: 2008
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28. FormaÃÃo de biofilme em aÃo inoxidÃvel por Aeromonas hydrophila e Staphylococcus aureus sob diferentes condiÃÃes de cultivo / Biofilm formation by Aeromonas hydrophila and Staphylococcus aureus on stainless steel AISI 304 in different conditions of cultivation
The microbial biofilm formation in surfaces used in food processing, like stainless steel, has been the focus in several researches in function of the injuries of its occurrence. These communities can act as constant point of contamination and cause other losses, as surface corrosion. In this context, Staphylococcus aureus and Aeromonas hydrophila are consid
Publicado em: 2008
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29. The design of a very high-Q superconductor electromechanical clock
We discuss the properties of an electromechanical oscillator whose operation is based upon the cyclic, quasi-conservative conversion between gravitational potential, kinetic, and magnetic energies. The system consists of a strong-pinning type-II superconductor square loop subjected to a constant external force and to magnetic fields. The loop oscillates in t
Brazilian Journal of Physics. Publicado em: 2007-06
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30. An estimate of the magnetic lossesin reactors with natural saturation / Uma estimativa das perdas magnÃticas em reatores com saturaÃÃo natural
This work has the purpose of showing an estimate of the modeling of power dissipated in ferromagnetic structures with profoundly saturated parts, through the behavior of the magnetic induction wave form experimented in many parts of the structure when used in saturated reactors. For each one of the analyzed prototypes, the bonding forms of the primary windin
Publicado em: 2006
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31. INFLUENCE ANALYSIS OF THE SWITCHING FREQUENCY AND INPUT CURRENT RIPPLE ON THE PFC CONVERTER DESIGN AIMING TO MINIMIZE THE MAGNETIC VOLUME / ANÁLISE DA INFLUÊNCIA DA FREQÜÊNCIA DE COMUTAÇÃO E DA ONDULAÇÃO DA CORRENTE DE ENTRADA NO PROJETO DE CONVERSORES PFC PARA MINIMIZAÇÃO DO VOLUME DE MAGNÉTICOS
This work investigates the relationship among the magnetic volume, switching frequency and input current ripple of a single-phase, 1kW boost based PFC converter with universal input voltage range, complying with the international standards IEC 61000-3-2 and CISPR 22. Such topology is frequently applicable in Telecom power supplies modules, as a part of a Dis
Publicado em: 2006
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32. The effect of the carbon content on the grain size coarsening and on the magnetic properties of the semi processed electrical steels after the final annealing. / O efeito do carbono no aumento do tamanho de grão e nas propriedades magnéticas de aços elétricos semiprocessados após o recozimento final.
Annealing applied by the motors plants that are made on the semi processed electrical steels without an exact and precisious control of the decarburization on the lamination can brings undesirable results on the grain size coarsening and as a result an increasing on the core losses with a significant depreciation on the efficiency of the electrical motors. M
Publicado em: 2006
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33. A new current transformer model
This paper presents a current transformer model that is useful on low frequency applications. To describe the iron core magnetic behaviour of the iron core, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear
Sba: Controle & Automação Sociedade Brasileira de Automatica. Publicado em: 2005-09
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34. MAGNETOSTRICÇÃO E RUÍDO BARKHAUSEN EM AÇOS ELÉTRICOS DE GRÃO NÃO-ORIENTADO
Non-oriented electrical steels (NO) studied in this work are used in applications that demand isotropy of magnetic properties along the plane of the sheet, which the magnetic field is applied in different angles with respect to the rolling direction (RD). In magnetic materials as the steels, magnetic losses can be separated in two components: low induction l
Publicado em: 2005
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35. Influências do ângulo de corte e da anisotropia nas propriedades magnéticas dos aços elétricos o efeito textura / Influences of cut angle and anisotropy in the magnetic properties of electric steel - the texture effect
The present thesis aims firstly to argue theoretically, of what occurs in carbon steel and silicon steel plates for electric ends, when used in transformers, electric motors and generators, and other electromagnetic devices. Secondly, experimental data and results are used to justify the "new" concepts adopted the analyses and conclusions drawn with samples
Publicado em: 2005
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36. Longitudinal magnetic field effect on the electrical breakdown in low pressure gases
The electrical breakdown has been investigated for low-pressure argon and nitrogen discharges under the influence of an external longitudinal magnetic field. Plane-parallel aluminum electrodes (5 cm diameter) separated by a variable distance d (4.0 cm < d < 11.0 cm) were sustained with a dc voltage (0 < V < 1 kV). A Helmholtz coil was used to produce an unif
Brazilian Journal of Physics. Publicado em: 2004-12