The Experts below are selected from a list of 1374 Experts worldwide ranked by ideXlab platform
G U Xuesong - One of the best experts on this subject based on the ideXlab platform.
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wide frequency measurement of transfer impedance and transfer admittance of Shielded Cable
Chinese Journal of Radio Science, 2007Co-Authors: G U XuesongAbstract:The transfer impedance and transfer admittance are two important parameters for expressing numerically the mechanism that allows the passage of electromagnetic energy across the Cable Shield. Based on the transmission line theory, a simple method is presented to measure the transfer impedance and transfer admittance of the Shielded Cable in magnitude as well as in phase over the frequency range (0.1MHz~10MHz) which covers the main interference frequencies in power system. In order to avoid occurrence of resonance, a shorter Cable sample is choosen to carry out the rational results for high frequency measurement. With the proposed method, the test system can be quickly set up and run.A coaxial Cable with a braided Shield is measured and compared with the existing method, the validity of the method presented in this paper is confirmed. As an extension, the method may be applied to the multi-core Shielded Cable.
Antonio Sarolic - One of the best experts on this subject based on the ideXlab platform.
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Slot Antenna in a Coaxial Cable Shield – Coupling Loss Computational Analysis
2019Co-Authors: Andela Matkovic, Antonio SarolicAbstract:A slot antenna in a coaxial Cable Shield was modelled and simulated in FEKO, to calculate the coupling loss in the broadside direction. Three different lengths of a transverse slot were simulated to investigate the coupling loss sensitivity to the slot length. The results were compared and found to agree with the previously published coupling loss measurements of a similar practical realization of the slot. The coupling loss of the analyzed model is shown to be inversely proportional to the slot length.
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Radiating Slot in the Coaxial Cable Shield: Measurement Based Characterization
Journal of communications software and systems, 2015Co-Authors: Antonio Sarolic, Zlatko Živković, Damir Senic, Niko IštukAbstract:The paper presents the comprehensive experimental study of radiation characteristics of a single slot in a coaxial Cable Shield. The slot was realized in four different embodiments, which varied by slot orientation and length. Three orthogonal polarizations of radiated electric field were analyzed along the axis perpendicular to Cable, broadside to the slot, in a broadband frequency range (80-1000 MHz). The analysis was based on thorough measurements of the coupling loss, which is the common parameter for the leaky Cable characterization. The obtained results showed that the electric field component longitudinal to the Cable axis considerably dominates over other two orthogonal components, for all four slot types. Doubling the length of the slot caused a ca. 20 dB increase of the radiated field. Different slot orientations, having the same length in the cross-section projection, yielded approximately equal field strengths. The results of this experimental study clearly and visibly demonstrate the radiating slot field dependence on polarization and slot geometry in a wide frequency range. Thus they are useful for planning of wireless communication systems based on radiating Cables, as well as for understanding polarization related issues in such systems.
M. Izadi - One of the best experts on this subject based on the ideXlab platform.
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Voltage distribution of a wind turbine transformer under direct lightning strike: effects of the grounding of Cable Shield
2016Co-Authors: Rebaz J. Ahmed, Chandima Gomes, Zainal Kadir, M. IzadiAbstract:In this paper we consider wind energy generators as tall structures, thus the reflections of the current of a direct lightning strike, at various interfaces, have been included in the computational model. A significant effect of such reflections on the voltage distribution has been observed thus, inclusion of the reflections in the computation model has been justified. The study focuses on over voltage at critical locations that have been reported in the literature as having high probability of lightning damage. All parts related to the power generation in a wind turbine, including the step up transformer are modeled by lumped parameters using the Matlab/Simulink software. The transient response is obtained by applying the lightning impulse current to the equivalent circuit under several values of grounding resistance and several Cable sheath grounding methods with different lightning strike waveforms. The results show that the location of the Cable Shield grounding and the grounding resistance values have significant influence on the produced over voltage waveforms at the input and output of transformer terminals. Appropriate surge protection devices for avoiding dangerous over voltage are proposed to reduce harmful effects.
Shozo Sekioka - One of the best experts on this subject based on the ideXlab platform.
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Earth System and Improvement plan for Shield of Cable with Separable Connector
2018 34th International Conference on Lightning Protection (ICLP), 2018Co-Authors: Kenichi Seki, Takashi Tsuchida, Nobuya Oka, Hiroyuki Sugihara, Atsushi Akiba, Toru Hiroki, Hiroyuki Tada, Masahiro Yamazaki, Shozo SekiokaAbstract:Separable connector is used for connecting a Cable to a switch gear in new energy generation sites because of its compact size. One of terminations of Cable Shield is not sometimes earthed in order to reduce power loss due to Shield current. A part of the separable connector made up of semi- conducting material is connected to an earthing system. Furthermore, the end of the Shield layers of the Cable contacts with semiconducting material of separable connector. The Shield layer of a Cable might be regarded to be connected to the earthing system through resistance. Hence, the authors carried out impulse tests for separable connector with Cable. This paper presents some remarkable results. Lightning overvoltage causes a serious damage in the semiconducting layer of separable connector when one of the terminations of the Cable Shield is not earthed. An effective method not to cause a damage in the semiconducting layer of the separable connector is the use of a surge protective device between the earth terminal of a separable connector and Cable Shield.
V.m. Primiani - One of the best experts on this subject based on the ideXlab platform.
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On the Robustness of Cable Shielding Effectiveness Measurements in Reverberation Chamber
2005 IEEE Instrumentationand Measurement Technology Conference Proceedings, 2005Co-Authors: V.m. PrimianiAbstract:The paper presents some Shielding effectiveness measurements carried out on Shielded Cables. The adopted procedure is based on the use of a reverberation chamber which allows to create a more realistic environment for the Cable under test. Inside a reverberation chamber the Cable is excited by a field statistically uniform, coming from whatever direction and with whatever polarization, moreover, no test fixture is required to mount the Cable under test. The obtained results show the robustness of the measurement with respect to Cable positioning, routing and orientation inside the chamber working volume. Due to the statistical nature of the exciting field the response does not exhibit resonances as achieved with traditional methods. A relationship between the measured Shielding effectiveness and the transfer impedance of the Cable Shield can be also assessed
