Searched for: department%3A%22Electrical%255C%252BSustainable%255C%252BEnergy%22
(21 - 40 of 319)
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Popov, M. (author), Smeets, R.P.P. (author), Van der Sluis, L. (author), De Herdt, H. (author), Declerq, J. (author)The work presented in this paper deals with the investigation of circuit breaker prestrike effect that occurs during energizing a distribution transformer. An experimental test setup that consists of a supply transformer, a vacuum circuit breaker (VCB), a cable and a test transformer is built, and the prestrikes in the VCB are recorded. The test...journal article 2009
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Hoogendorp, G. (author), Popov, M. (author), Van der Sluis, L. (author)This letter deals with the hybrid modeling of transformers and the determination of interturn voltage distribution in transformers with layer-type windings. The hybrid model uses a combination of a multiconductor transmission-line model and a single transmission-line model. The good agreement between computed and measured voltage waveforms shows...journal article 2009
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Bajracharya, G. (author), Koltunowicz, T. (author), Negenborn, R.R. (author), Papp, Z. (author), Djairam, D. (author), De Schutter, B. (author), Smit, J.J. (author)In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based on the health state, the failure rate of the...conference paper 2009
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On the surface roughness development of hydrogenated amorphous silicon deposited at low growth ratesWank, M.A. (author), Van Swaaij, R.A.C.M.M. (author), Van de Sanden, M.C.M. (author)The surface roughness evolution of hydrogenated amorphous silicon (a-Si:H) films has been studied using in situ spectroscopic ellipsometry for a temperature range of 150–400?°C. The effect of external rf substrate biasing on the coalescence phase is discussed and a removal/densification of a hydrogen-rich layer is suggested to explain the...journal article 2009
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Ani, S.O. (author), Polinder, H. (author), Ferreira, J.A. (author), Ockels, W.J. (author)This paper discusses the possibilities of applying high temperature superconducting (HTS) synchronous motor to Superbus, an alternative and sustainable type of public transportation developed at TU Delft. Two important factors within the Superbus drive that influence the operating range are weight and efficiency: increasing the weight results in...conference paper 2009
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Bajracharya, G. (author), Koltunowicz, T. (author), Negenborn, R.R. (author), Papp, Z. (author), Djairam, D. (author), De Schutter, B. (author), Smit, J.J. (author)In this paper, a model predictive framework is used to optimize the operation and maintenance actions of power system equipment based on the predicted health sate of this equipment. In particular, this framework is used to predict the health state of transformers based on their usage. The health state of a transformer is hereby given by the hot...report 2009
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Jäger, K. (author), Zeman, M. (author)We present a mathematical model that relates the surface morphology of randomly surface-textured thin films with the intensity distribution of scattered light. The model is based on the first order Born approximation [see e.g., M. Born and E. Wolf, Principles of Optics, 7th ed. (Cambridge University Press, Cambridge, England, 1999) ] and on...journal article 2009
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Pierik, J. (author), Axelsson, U. (author), Eriksson, E. (author), Salomonsson, D. (author), Bauer, P. (author), Czech, B. (author)EeFarm-II is used to evaluate 13 different electrical systems for a 200 MW wind farm with a 100 km connection to shore. The evaluation is based on component manufacturer data of 2009. AC systems are compared to systems with DC connections inside the wind farm and DC connection to shore. Two options have the best performance for this wind farm...journal article 2010
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- Van Elzakker, G. (author) doctoral thesis 2010
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Westra, J.M. (author), Vavrunkova, V. (author), Sutta, P. (author), Van Swaaij, R.A.C.M.M. (author), Zeman, M. (author)Thin-film poly-crystalline silicon (poly c-Si) on glass obtained by crystallization of an amorphous silicon (a-Si) film is a promising material for low cost, high efficiency solar cells. Our approach to obtain this material is to crystallize a-Si films on glass by solid phase crystallization (SPC). As the grain size of SPC poly c-Si films will...journal article 2010
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Chevtchenko, O.A. (author), Smit, J.J. (author), Geschiere, A. (author)Cryostat for a high-temperature superconducting power cable, comprising concentric tubes, an annular region between said tubes, wherein a multilayer thermal insulation and getter material for supporting high vacuum conditions are provided in said annular region, and wherein the multilayer insulation comprises reflective layers separated by...patent 2010
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Isabella, O. (author), Kr?, J. (author), Zeman, M. (author)Substrates with a modulated surface texture were prepared by combining different interface morphologies. The spatial frequency surface representation method is used to evaluate the surface modulation. When combining morphologies with appropriate geometrical features, substrates exhibit an increased scattering level in a broad wavelength region....journal article 2010
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Yuan, Z. (author)In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of PFCDs, the trend is that mechanical PFCDs are...doctoral thesis 2010
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Jarolimek, K. (author), De Groot, R.A. (author), De Wijs, G.A. (author), Zeman, M. (author)We present a theoretical study of hydrogenated amorphous silicon nitride (a-SiNx:H), with equal concentrations of Si and N atoms (x=1), for two considerably different densities (2.0 and 3.0?g/cm3). Densities and hydrogen concentration were chosen according to experimental data. Using first-principles molecular-dynamics within density-functional...journal article 2010
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Andritsch, T.M. (author)Main goal of the research described in this PhD thesis was to determine the influences of filler size, material and distribution on the DC breakdown strength, permittivity and space charge behaviour of nanocomposites. This should lay the groundwork for tailored insulation materials for HVDC applications. Examples for this are medical and...doctoral thesis 2010
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Wank, M.A. (author), Van Swaaij, R.A.C.M.M. (author), Kudlacek, P. (author), Van de Sanden, M.C.M. (author), Zeman, M. (author)We have applied pulse-shaped biasing to the expanding thermal plasma deposition of hydrogenated amorphous silicon at substrate temperatures ? 200?°C and growth rates around 1 nm/s. Substrate voltage measurements and measurements with a retarding field energy analyzer demonstrate the achieved control over the ion energy distribution for...journal article 2010
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Lipovek, B. (author), Kr?, J. (author), Isabella, O. (author), Zeman, M. (author), Topi?, M. (author)Diffusive dielectric materials such as white paint have been demonstrated as effective back reflectors in the photovoltaic technology. In this work, a one-dimensional (1D) optical modeling approach for simulation of white paint films is developed and implemented in a 1D optical simulator for thin-film solar cells. The parameters of white paint,...journal article 2010
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Cvoric, D. (author)Increasing levels of fault currents in utility grids are expected to result in mechanical and thermal overstresses of different power system components. To cope with these increased levels, expensive upgrades and replacements of currently employed Circuit Breakers might be required in the near future. Fault Current Limiters (FCLs) are expected...doctoral thesis 2010
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Solntsev, S. (author), Zeman, M. (author)In thin-film silicon solar cells (TFSC) efficient light management is essential in order to increase energy conversion efficiency. The application of nano-scale periodic gratings (PG) is a promising method to enhance absorption in the absorber layers of TFSC since they can efficiently scatter the incident light. Carefully designed gratings give...journal article 2011
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Wank, M.A. (author)Our modern lifestyle is currently fueled by two billion years of accumulated energy reserves. For several years now there has been a strong rise in research interest and more recently also implementation of renewable energy sources in the European Union. Driving factors for these developments are the increasing awareness of global warming in our...doctoral thesis 2011
Searched for: department%3A%22Electrical%255C%252BSustainable%255C%252BEnergy%22
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