1,721,147 research outputs found
Calculation of lightning electromagnetic fields in presence of a lossy ground with frequency dependent parameters
No full textIndirect-Lightning Performance of Distribution Lines: Influence of Protection devices
No full textFor an improved assessment of the indirectlightning performances of distribution systems, the real configuration of the system, which means the topology, the presence of protection devices such as surge arresters and shielding wire/neutral groundings, must be taken into account. In this paper, the indirect lightning performance of a distribution line with realistic configuration is evaluated by means a statistical procedure based on the Monte Carlo method. Accurate models are used to evaluate the lightning induced overvoltages, in order to estimate the effects of arresters spacing and characteristics.
Results relevant to a line length of 100 km, as it is often presented in the power/lightning literature, appear to be not as useful as those relevant to the real system of interest
Derivation of telegrapher's equations and field-to-transmission line interaction
No full textThe evaluation of electromagnetic field coupling to transmission lines is an important problem in electromagnetic compatibility. The use of the transmission line (TL) approximation theory has permitted the solution of a large range of problems (e. g. lightning and EMP interaction with power lines). However, the continual increase in operating frequency of products and higher-frequency sources of disturbances (such as UWB systems) makes TL basic assumptions no longer acceptable for a certain number of applications. In the last decade or so, the generalization of classical TL theory to take into account high frequency effects has emerged as an important topic of study in electromagnetic compatibility. This effort resulted in the elaboration of the so-called "generalized" or "full-wave" TL theory, which incorporates high frequency radiation effects, while keeping the relative simplicity of TL equations
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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