Dynamic voltage restorer development and testing

The growing use of sensitive loads in the electric power system, especially in industrial applications, increases voltage sags related production losses considerably, stimulating a demand for power electronics' based solutions to mitigate the effects of such problems. This paper shows the implementation and some industrial certification tests of a power equipment prototype designed to correct sags and swells, a dynamic voltage restorer, which is one of the many possible solutions for voltage sags and swells problems Experimental results of a 75kVA prototype are shown both in laboratory and full load conditions, in a certification institution (IEE-USP). © 2011 IEEE.

Produtividade, estabilidade e adaptabilidade em progênies de Myracrodruon urundeuva F.F. & M.F. Allemão-Anacardiaceae

The use and inadequate exploitation of natural resources is restricting the occurrence of aroeira (Myracrodruon urundeuva F.F. & M.F. Allemão), which now is on the FAO list of endangered species. This exploitation causes a decrease in the genetic base of M. urundeuva populations, which makes it difficult to find genotypes with stability and adaptability to different growing conditions. This study aimed at estimating the genetic variation and productivity, stability and adaptability of progenies of a M. urundeuva natural population, from the Ecological Station of Paulo de Faria-SP, under different planting systems. DBH (diameter at breast height) was evaluated in four progeny tests of M. urundeuva: i) planted with Anandenanthera falcata and Guazuma ulmifolia (TP-AMA); ii) single (TP-ASO); iii) planted with annual crops (TP-SAF) and iv) planted with Corymbia citriodora (TP-EUCA), installed in Selvíria-MS. The experimental design consisted of complete randomized blocks with three replications and a variable number of plants per plot in each of the four planting systems. From the joint analysis of the planting systems studied, it was found that: i) there were variations among planting systems particularly in TP-SAF; ii) only in TP-EUCA it was possible to detect variations among the progenies; iii) the effects of the genotype x environment interaction were not significant. Thereby, the harmonic mean of genotypic values (MHVG), the relative performance of genotypic values from the mean of each site (PRVG) and the harmonic mean of the relative performance of genotypic values (MHPRVG) for DBH showed, respectively: progenies with greater stability, adaptability, and stability and simultaneous adaptability within different planting systems. The use of these selection criteria provided a more refined selection of the best progenies of M. urundeuva under the different planting systems studied.

Strategies to reduce the number of variables and the combinatorial search space of the multistage transmission expansion planning problem

This paper proposes strategies to reduce the number of variables and the combinatorial search space of the multistage transmission expansion planning problem (TEP). The concept of the binary numeral system (BNS) is used to reduce the number of binary and continuous variables related to the candidate transmission lines and network constraints that are connected with them. The construction phase of greedy randomized adaptive search procedure (GRASP-CP) and additional constraints, obtained from power flow equilibrium in an electric power system are employed for more reduction in search space. The multistage TEP problem is modeled like a mixed binary linear programming problem and solved using a commercial solver with a low computational time. The results of one test system and two real systems are presented in order to show the efficiency of the proposed solution technique. © 1969-2012 IEEE.

The modernization of bank supervision

Includes bibliography

Improving the grid operation and reliability cost of distribution systems with dispersed generation

In this work, a mathematical model to analyze the impact of the installation and operation of dispersed generation units in power distribution systems is proposed. The main focus is to determine the trade-off between the reliability and operational costs of distribution networks when the operation of isolated areas is allowed. In order to increase the system operator revenue, an optimal power flow makes use of the different energy prices offered by the dispersed generation connected to the grid. Simultaneously, the type and location of the protective devices initially installed on the protection system are reconfigured in order to minimize the interruption and expenditure of adjusting the protection system to conditions imposed by the operation of dispersed units. The interruption cost regards the unsupplied energy to customers in secure systems but affected by the normal tripping of protective devices. Therefore, the tripping of fuses, reclosers, and overcurrent relays aims to protect the system against both temporary and permanent fault types. Additionally, in order to reduce the average duration of the system interruption experienced by customers, the isolated operation of dispersed generation is allowed by installing directional overcurrent relays with synchronized reclose capabilities. A 135-bus real distribution system is used in order to show the advantages of using the mathematical model proposed. © 1969-2012 IEEE.

Simplified procedure to estimate the resistance parameters of transmission lines

An alternative and simplified procedure is described to estimate the longitudinal resistances of transmission lines based on the real-time load profile. This method proposes to estimate the resistance parameters from the synchronized measurements of complex currents and complex voltages at the sending and receiving ends of transmission systems. The synchronized measurements can be in practice obtained using phasor measurement units (PMUs). © 2012 Springer-Verlag Berlin Heidelberg.

Concentrado proteico de vísceras de surubim híbrido em dietas para cachara

The current study evaluated the growth performance and the haematological profile of barred sorubim fed with levels of hybrid sorubim viscera protein concentrate (0.0; 5.0; 10.0 e 15.0%) in isoprotein and isoenergetic diets. Eighty fish with an average initial weight of 39.8 ± 0.28 g and an average initial length of 19.92 ± 0.25 cm were distributed in 16 aquaria of 60 L, with recirculation system and temperature control, during 35 days. The experimental design was completely randomized with four treatments and four replications. For the growth performance assay were analyzed the follows variables: weight gain (WG), feed consumption (FC), apparent feed conversion ratio (AFCR) and protein efficiency ratio (PER). Furthermore, the hemogram were assessed on the treated fish with levels of protein concentrate. It was observed no significant difference (P>0.05) for all the parameters evaluated. It was concluded that the protein concentrate from hybrid sorubim viscera can be included up to 15% in diets for barred sorubim juveniles without negative response on the performance and health.

Um método para detecção e classificação de curtos-circuitos em redes de distribuição de energia elétrica baseado na transformada de Fourier e em redes neurais artificiais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metodologias de medição de energia elétrica reativa (varh) e erros de medição em equipamentos eletrônicos de (varh)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação do método de Newton desacoplado para o fluxo de carga continuado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Restauração automática de redes de distribuição de energia elétrica de grande porte com geração distribuída

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

Apresentação de uma indústria sucroalcooleira sob os conceitos de microrrede de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Estudo da teoria de potência conservativa para análise de sistemas elétricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Método previsor-corretor primal-dual de pontos interiores em problemas multiobjetivo de despacho econômico e ambiental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposição de uma técnica de parametrização geométrica para o fluxo de carga continuado baseado nas variáveis tensão e fator de carregamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)