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In this work, it is proposed to calculate the sensitivity of parameters, based on analytical calculation, of repowered system between two electric generators, an induction generator and a synchronous generator, connected to a common bus in permanent regime, subject to a non-linear load. It is proposed a repowered system with simulated data where, based on percentage variations in the base values of...
This work presents images encoding and decoding using the theory of conformal mapping. The conformal mapping theory made changes in the domain of problems without modifying physical characteristics between the domains. Images were utilized and are transported between domains using transformation functions like encrypt keys. Developed method showed to be able to preserve original images characteristics...
This paper presents an approach of investment risk analysis for small hydro power plants (SHPPs) considering energy trade in the short-term market in Brazil. The Monte Carlo Method, associated with a Cholesky decomposition, is applied to stochastic models to generate synthetic time series for water inflow and short-term electricity price. An economic approach is presented taking into account taxation...
This paper proposes a development's prediction model based on Artificial Neural Network. The methodology proposed consists in: i) countries selection; ii) selection and obtainment of indicators referring to the selected countries; iii) proposal prediction model; iv) Artificial Neural Network training and validation. The results indicated predicted values close to the real values of the Brazilian indicators...
The approach of this paper it is about voltage conformity delivered to the final customer, on electricity distribution networks. Have obtained physical and electrical characteristics information from the network coming from the database of the electricity company. The study presents the process of voltages estimation in primary and secondary circuits wich estimation of indicators of voltage violation...
The purpose of this work is to find the values of the electric parameters of synchronous and induction machines in order to validate the electrical interactions between an induction generator and a synchronous generator. The two generators will be connected in two ways: i) isolated to the common bus and ii) jointly connected to the common bus in permanent regime, subject to non-linear load. The results...
This paper deals with the computation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The computer program implemented used in the mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for homogeneous soil and soil stratified in two layers. The results obtained...
Considering the actual environmental appeal due to excessive consumption of fossil fuels, is relevant the research and development of green power sources in order to conserve the natural resources. Wind energy has become a target of researches and highlights a clean energy scenario. Electrical machines have its reversibility and, operating as generators, can be useful for wind energy aaplications...
This paper performs a comparative analysis between two types of reactive compensation in typical industrial systems: by capacitors banks (capacitive compensation) and synchronous machine (synchronous compensation). For the tests a busbar subjected to harmonic distortion and with a low power factor is implemented. The results show equivalent compensation for both cases, however synchronous machine...
This paper proposed experimental method that uses geoelectrical prospection to correlate variations in the soil electrical resistivity produced by the application of agricultural supplies, such as nitrogen, phosphor, potassium and limestone. The proposed method uses a three-dimensional stratification methodology to enable the mapping of soil dynamic aimed in the different proportions of supplies applied...
This paper is an experimental and theoretical method developed for in situ applications that uses a geoelectrical method, the Wenner method, to correlate the changes in electrical resistance of soil produced by chemical fertilization. The developed methodology enables: i) map different influences of some fertilizers in the soil non-invasively, ie, it is a non-destructive method of soil evaluation,...
The purpose of this paper is to compare mathematical modeling and practical bench in order to validate the electrical interactions between an induction generator and a synchronous generator. Two generators was connected to a common bus in steady state, subject to non-linear load. The results comparing modeling and bench tests show that the induction generator besides the active power increasing, has...
This paper is an experimental and theoretical method developed in laboratory bench that uses a geoelectrical method, the Wenner method, to correlate the changes in electrical resistance of soil produced by chemical fertilization. The developed methodology allowed to know the dynamic behavior that some common fertilizer causes on the electrical resistance measurements of the soil under study. The applied...
This paper deals with the optimization of grounding grids geometry. The goal is to reduce the amount of material to deploy a grounding grid, while keeping the system security. The touch voltages, step voltages, GPR and ground resistance are parameters of grounding grids and are related to safety aspect. Also discussed is a genetic algorithm used for optimizing ground grids, which can assume any form...
This paper proposes a methodology based on system connections to calculate its complexity. There are proposed two study cases: the dining Chinese philosophers problem and the distribution center. Both studies are modeled using the theory of discrete event systems and simulated in different contexts in order to measure their complexities. The obtained results present i) the static complexity as a limiting...
Solar water heating in homes of low-income families as Energy Efficiency Action enables energetic benefits from points of view of the consumer and the Brazilian electrical system, thereby reducing environmental impacts associated with generation, transmission and distribution of electricity. The purpose of the present study is to evaluate these gains through measurement and verification methodology...
This paper presents methodology for validation of soil compaction measuring devices based on cone index, allowing procedures such as: i) comparison between equipment, ii) analyzes of accuracy and iii) repeatability, important parameters in the validation of measurement instruments. The methodology consists in using soil samples with a particular compaction discretized from the height of the mold used,...
This paper aims to simulate and analyze an isolated full-bridge DC/DC boost converter, for photovoltaic panels, running a modified perturb and observe maximum power point tracking method. The zero voltage switching technique was used in order to minimize the losses of the converter for a wide range of solar operation. The efficiency of the power transfer is higher than 90% for a large solar operating...
Soil Stratification methods are used to estimate soil geoelectrical parameters. Several stratification methods are available, but reducing the error estimation introduced by such methods still poses as a challenge. The purpose of this work is to present a heuristic algorithm applied to the optimization of geoelectrical prospection process. The goal is to estimate soil parameters, such as the amount...
This paper deals with the calculation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for soil stratified in two layers. Moreover, the results obtained by the Variable Currents Method (VCM) have been compared...
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