Searched for: department:"Electrical%5C+Sustainable%5C+Energy"
(161 - 180 of 187)

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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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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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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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Wank, 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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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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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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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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Veldman, E. (author), Geldtmeijer, D.A.M. (author), Slootweg, J.G. (author)
The transition towards a more sustainable energ y supply system causes changes in the supply and demand of energ y. It requires a more flexible and efficient operation of the electricity distribution grids. It calls for a smart grid with intelligent control embedded in the grids to incorporate electricity storage and controllable loads. This...
conference paper 2009
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Xyngi, I. (author), Ishchenko, A. (author), Popov, M. (author), Van der Sluis, L. (author)
This letter describes the transient stability analysis of a 10-kV distribution network with wind generators, microturbines, and CHP plants. The network being modeled in Matlab/Simulink takes into account detailed dynamic models of the generators. Fault simulations at various locations are investigated. For the studied cases, the critical...
journal article 2009
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Jarolimek, K. (author), De Groot, R.A. (author), De Wijs, G.A. (author), Zeman, M. (author)
We use a molecular-dynamics simulation within density-functional theory to prepare realistic structures of hydrogenated amorphous silicon. The procedure consists of heating a crystalline structure of Si64H8 to 2370 K, creating a liquid and subsequently cooling it down to room temperature. The effect of the cooling rate is examined. We prepared a...
journal article 2009
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Krc, J. (author), Zeman, M. (author), Luxembourg, S.L. (author), Topic, M. (author)
A concept of a modulated one-dimensional photonic-crystal (PC) structure is introduced as a back reflector for thin-film solar cells. The structure comprises two PC parts, each consisting of layers of different thicknesses. Using layers of amorphous silicon and amorphous silicon nitride a reflectance close to 100% is achieved over a broad...
journal article 2009
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Bang, D. (author), Polinder, H. (author), Shrestha, G. (author), Ferreira, J.A. (author)
conference paper 2009
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Shrestha, G. (author), Polinder, H. (author), Bang, D. (author), Jassal, A.K. (author), Ferreira, J.A. (author)
A direct drive generator used in wind turbine has high energy yield compared to other drivetrain topologies and low maintenance is expected as the technology matures. On the other hand direct drive generator weight and size increases rapidly when scaled up to larger units. This paper will investigate the possibility of weight reduction of large...
conference paper 2009
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Zhou, Y. (author), Bauer, P. (author), Ferreira, J.A. (author), Pierik, J. (author)
Doubly fed induction generator (DFIG) still shares a large part in today's wind power market. It provides the benefits of variable speed operation cost-effectively, and can control its active and reactive power independently. Crowbar protection is often adopted to protect the rotor-side voltage source converter (VSC) from transient overcurrent...
journal article 2009
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Pieters, B.E. (author), Stiebig, H. (author), Zeman, M. (author), Van Swaaij, R.A.C.M.M. (author)
Microcrystalline silicon (?c-Si:H) is a promising material for application in multijunction thin-film solar cells. A detailed analysis of the optoelectronic properties is impeded by its complex microstructural properties. In this work we will focus on determining the mobility gap of ?c-Si:H material. Commonly a value of 1.1?eV is found, similar...
journal article 2009
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Zhao, D. (author), Ferreira, J.A. (author), Roc'h, A. (author), Leferink, F. (author)
Filters used in electromagnetic interference suppression are often described in literature on drive systems and have become a standard solution in industry. The effect of the commercial off-the-shelf filter depends significantly on how it is installed. A model that includes the installation parameters is made first and then the parameters of the...
journal article 2009
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Papaefthymiou, G. (author), Kurowicka, D. (author)
The increasing penetration of renewable generation in power systems necessitates the modeling of this stochastic system infeed in operation and planning studies. The system analysis leads to multivariate uncertainty analysis problems, involving non-Normal correlated random variables. In this context, the modeling of stochastic dependence is...
journal article 2009
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De Jong, E.C.W. (author), Ferreira, B.J.A. (author), Bauer, P. (author)
A means for power electronics to exploit the level of 3-D packaging already being implemented in compact consumer products, such as digital cameras, is investigated in order to increase its power density. The increase in functionality and usage of printed circuit board (PCB) in power electronic converters is highlighted and improvements proposed...
journal article 2008
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Cichecki, P. (author), Jongen, R.A. (author), Gulski, E. (author), Smit, J.J. (author), Quak, B. (author), Petzold, F. (author), De Vries, F. (author)
journal article 2008
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Gulski, E. (author), Cichecki, P. (author), Wester, F. (author), Smit, J.J. (author), Bodega, R. (author), Hermans, T.J.W.H. (author), Seitz, P.P. (author), Quak, B. (author), De Vries, F. (author)
In addition to after-laying of new-installed high voltage (HV) power cables the use of on-site non-destructive on-site testing and diagnosis of service aged power cables is becoming an important issue to determine the actual condition of the cable systems and to determine the future performances. In this paper based on field experience an...
journal article 2008
Searched for: department:"Electrical%5C+Sustainable%5C+Energy"
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