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The paper aims at defining a methodology to evaluate the lightning performance of a system of overhead distribution lines. As is well known, the evaluation of the lightning performance relies generally on a Monte Carlo approach that generates many different lightning events and calculates the corresponding overvoltages. To perform such calculation, the power system computer aided design (PSCAD) module developed in the companion paper is adopted. However, as any call to PSCAD implies a nonnegligible computational effort, here an efficient approach is presented in order to limit the number of simulations as much as possible. The obtained results are compared with the ones provided by other available techniques both on simple structures in order to highlight the main features of the method and on a typical Italian distribution network segment. The comparative analysis shows good agreement between the methods and the effectiveness of the proposed technique in terms of computational effort reduction. [ABSTRACT FROM PUBLISHER]

Feature selective validation (FSV) is a heuristic method for quantifying the (dis)similarity of two datasets. The computational burden of obtaining the FSV values might be unnecessarily high if datasets with large numbers of points are used. While this may not be an important issue per se it is an important issue for future developments in FSV such as real-time processing or where multidimensional FSV is needed. Coupled with the issue of dataset size, is the issue of datasets having “missing” values. This may come about because of a practical difficulty or because of noise or other confounding factors making some data points unreliable. These issues relate to the question “what is the effect on FSV quantification of reducing or removing data points from a comparison—i.e., down- or undersampling data?” This paper uses three strategies to achieve this from known datasets. This paper demonstrates, through a representative sample of 16 pairs of datasets, that FSV is robust to changes providing a minimum dataset size of approximately 200 points is maintained. It is robust also for up to approximately 10% “missing” data, providing this does not result in a continuous region of missed data. [ABSTRACT FROM PUBLISHER]

One important aspect of the feature selective validation (FSV) method is that it classifies comparison data into a number of natural-language categories. This allows comparison data generated by FSV to be compared with equivalent “visual” comparisons obtained using the visual rating scale. Previous research has shown a close relationship between visual assessment and FSV generated data using the resulting confidence histograms. In all cases, the category membership functions are “crisp”: that is data on the FSV-value axis falls distinctly into one category. The companion paper to this Investigating Confidence histograms and Classification in FSV: Part I. Fuzzy FSV investigated whether allowing probabilistic membership of categories could improve the comparison between FSV and visual assessment. That paper showed that such an approach produced limited improvement and, as a consequence, showed that FSV confidence histograms are robust to flexibility in category boundaries. This paper investigates the effect of redefining some, but not all, category boundaries based around the mode category. This “float” approach does show some improvement in the comparison between FSV and visual assessment. [ABSTRACT FROM PUBLISHER]

This paper focuses on rigorous validation, verification, and testing methodologies applied to a commercial electromagnetic software package to ensure that as accurate as possible results are given dependent on the accuracy of the solution method, for instance, whether a full-wave or approximate numerical method is used. In this paper, the general availability of reliable benchmark results such as analytical solutions, measurements, results from other codes and other numerical methods, and general benchmarking activities will be presented. The cross-validation aspects, once the benchmark results are available, will be discussed with respect to amongst other sequential runs compared with parallel multcore/cluster runs or, with and without, GPU acceleration. Internal consistency checks (which are a required but not necessary condition when assessing the accuracy) such as power budget, mesh size convergence, or boundary condition error estimates are also covered. Special emphasis is put on the validation of the actual computational model that is used as input to simulations. This is necessary, for example, because incomplete representation of real geometry might ignore small details that are needed for the specific quantity that is analyzed. Also, uncertainties with regards to material parameters or transition impedances could lead to discrepancies between the computed results and reality that are not to be attributed to the electromagnetic solution as such, but rather the model generation. [ABSTRACT FROM PUBLISHER]

One important aspect of the feature selective validation (FSV) method is that it classifies comparison data into a number of natural-language categories. This allows comparison data generated by FSV to be compared with equivalent “visual” comparisons obtained using the visual rating scale. Previous research has shown a close relationship between visual assessment and FSV generated data using the resulting confidence histograms. In all cases, the category membership functions are “crisp”: that is data on the FSV value axis fall distinctly into one category. An important open question in FSV-based research, and for validation techniques generally, is whether allowed variability in these crisp category membership functions could further improve agreement with the visual assessment. A similar and related question is how robust is FSV to variation in the categorization algorithm. This paper and its associated “part II” present research aimed at developing a better understanding of the categorization of both visual and FSV data using nonsquare or variable boundary category membership functions. This first paper investigates the level of improvement to be expected by applying fuzzy logic to location of the category boundaries. The result is limited improvement to FSV, showing that FSV categorization is actually robust to variations in category boundaries. [ABSTRACT FROM PUBLISHER]

In this paper, the crosstalk effects in multilayer graphene nanoribbon (MLGNR) interconnects are evaluated and are compared with those in multiwalled carbon nanotube (MWCNT) interconnects in ternary integrated circuits at the 10 and 7 nm technologies. For a more precise evaluation, the five-line bus architecture is considered. Furthermore, the effects of the top and bottom aggressors are considered for a more accurate analysis in sub-10 nm dimensions. The active and passive shielding techniques are also applied to reduce the crosstalk effects. Our results indicate that the MLGNR interconnects outperform the MWCNTs, especially in the more realistic seven-line case, which also considers the effects of the bottom and top layer aggressors. Also, the advantages of the MLGNR interconnects become more significant when the node shrinks from 10 to 7 nm. The crosstalk delays of normal, passively shielded, and actively shielded five-line MLGNRs at 7 nm are on average 49%, 56%, and 54% lower compared to their MWCNT counterparts, respectively. These improvements are 36%, 36%, and 41% regarding the power. Moreover, the normal and actively shielded MLGNRs have 25% and 72% smaller crosstalk noise area than their MWCNT counterparts, respectively. The smaller crosstalk noise for MLGNR leads to noise-free signals at the end of both actively and passively shielded victim lines in ternary logic at the 10 and 7 nm technologies. [ABSTRACT FROM AUTHOR]

With the development of the ultrahigh voltage (UHV) and extra high voltage (EHV) electric power industry in China, gas insulated substation (GIS) is applied widely. Very fast transient overvoltage (VFTO) caused by disconnector operations in GIS may damage the insulation of equipment due to its high frequency and amplitude. As one of the main overvoltage protection equipments, the protection behavior of surge arresters has received extensive attention. In this paper, the residual voltage behavior, the impedance behavior, and the response behavior of five different representative arrester blocks when excited by VFTO and lightning are investigated, respectively. Experimental results present that when the current peak keeps constant, the residual voltage under VFTO is approximately 14.7%–18.2% higher than under the standard lightning impulse voltage (8/20 μs, LI). The arrester block presents different impedance behavior under VFTO and LI. It behaves dominantly inductively under LI and expresses an impedance converting behavior under VFTO. Furthermore, the diameter and the shape of arrester blocks have little impact on the ratio of V0 to $V_{{\rm 1mA}}$ under VFTO. Therefore, the protective effect of arresters varies slightly under VFTO and LI. Investigating behavior of arrester blocks under VFTO in comparison with under LI could be applied not only in VFTO simulation and insulation coordination but also in the design and the operating of metal oxide surge arrester in GIS. [ABSTRACT FROM AUTHOR]

This paper presents research extending the feature selective validation (FSV) method to quantitatively compare multiple datasets. The analytic hierarchy process is introduced to weight different FSV results when comparison is conducted by comparing multiple numerical results with their referencing counterparts. Only pairwise comparisons are required which simplify the process of comprehensive validation. The efficiency of this approach is demonstrated by the validation of a simplified crosstalk model. [ABSTRACT FROM PUBLISHER]

Improvements of a methodology [1] able to compute the parasitic electromagnetic emissions of a solar panel are presented in this paper in order to handle real solar panels. Thus, the method is able to take into account solar panels with triple-junction solar cells, series or shunt power regulation system, and honeycomb composite panels. This numerical method is validated experimentally by comparing the near magnetic field emitted by a real solar panel and calculated by the method. [ABSTRACT FROM PUBLISHER]

In automotive electronics, IC outputs are connected to a wide range of impedances generated by external circuitry or wiring harness. This load alteration, which is not fully covered by the established standard direct power injection (DPI), impacts the EMC immunity and should therefore be taken into account during susceptibility analyses. This paper introduces two S-parameter-based approaches which enable a simplified but sufficiently accurate assessment of the load dependency of the immunity. The proposed methods have been tested experimentally for a low-side driver and their validity is analyzed by comparison with measurement and large-signal simulation results. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate the computational affordability and accuracy of a leap-frog discontinuous Galerkin (LFDG) time-domain method for high intensity radiated fields assessment in electromagnetic compatibility for aerospace. The conformal truncation of the computational domain is discussed and formulated in the LFDG context. Numerical validations are performed on challenging test cases, in comparison to measurements and to other numerical methods, demonstrating the accuracy, efficiency, and scalability of the algorithm. [ABSTRACT FROM PUBLISHER]

This paper presents and discusses different approaches for the measurements of the shielding effectiveness of thick multilayered panels, based on the use of nested reverberation chambers. In particular, it is considered the case of thick multilayered panels, characterized by one highly reflecting face, like a protected composite laminate or a protected glazing window. The paper proposes a novel test procedure, which allows one to estimate from the measurement of a finite dimension panel, the shielding performance of an infinite material sheet against a reverberating field. The method is validated by comparison with the results of analytical simulations and provides accurate results in a wide frequency range, above the lowest-usable frequency of the outer chamber. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a new channel-base current function for lightning studies. Main features of the new function are presented, also by comparison with existing expressions; relevant advantages are highlighted. For this new function, closed-form solutions of the time integral (representing the transferred charge), of the Fourier transform, and of the specific energy are given. [ABSTRACT FROM AUTHOR]

This paper presents a two-dimensional discontinuous Galerkin time-domain (2-D DGTD) method for modeling arbitrarily shaped power-ground planes in high-speed electronics. The DGTD method has advantage over the finite-difference time-domain method in handling complex geometries, and allows high-order spatial discretization for improved accuracy. Its explicit time-stepping scheme also reduces computational cost compared to the implicit finite element time-domain method. The proposed method is validated against both measurement and commercial software to demonstrate its accuracy and efficiency. [ABSTRACT FROM AUTHOR]

Based on an equivalent single-conductor (ESC) model of multilayer graphene nanoribbon (MLGNR) interconnects with side contacts, comparative study on their distributed parameters and transmission characteristics is performed in this paper. It is found that the number of conducting channels of a metallic MLGNR interconnect is the linear function of its width and Fermi energy, which can be described by an analytical equation. Its equivalent inductance and capacitance in the ESC model can also be characterized by a set of closed-form equations. Furthermore, according to the ITRS projection, transmission performance of the MLGNR interconnects with different contacts are predicted and compared with their Cu and carbon nanotube counterparts at different technology nodes. Also, some numerical results prove that MLGNR interconnects can provide better performance than Cu wires in particular at intermediate level. Even with the maximum crosstalk impacts considered, the advantage of MLGNR interconnects over Cu wires can still be kept. [ABSTRACT FROM AUTHOR]

This paper concerns the use of a large reverberation chamber (RC) to test a wireless local area network system based on both 802.11b/g and 802.11n standards including multiple input and multiple output (MIMO). A whole link established between commercial devices operates inside the RC under different loading conditions, varying the stirrer rotating speed and the paddle dimensions. The effects of this multipath environment on system performance are checked measuring the number of cyclic redundancy check error and the number of data retries. The comparison between the two systems is done adopting the same chamber loading condition and also stressing the system reducing the load, up to the link connection limit. Results show the higher performance of the MIMO system, able to maintain a 6-Mb/s data rate connection also with a chamber quality factor of 21 000. The same RC is used to carry out a radiated immunity test. The undesired signal is both a modulated and continuous wave injected into the active channel and into adjacent channels. Results reveal the high robustness of the 802.11n standard with respect to b and g standards when it operates in a hostile environment reproduced by an RC. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a compact and wideband electromagnetic bandgap (EBG) structure using a defected ground structure (DGS) to significantly enhance the wideband suppression of power/ground noise coupling in multilayer packages and printed circuit boards. The proposed EBG structure is implemented simply by adding a rectangular-shaped DGS which is etched periodically onto the ground plane without changing any other geometrical parameter from a mushroom-type EBG structure. The DGS effects on the f _L and f _U are thoroughly analyzed using the dispersion characteristics. We experimentally verified that the proposed EBG structure achieved the wideband power/ground noise suppression (below −40 dB) between 2.5 and 16.2 GHz. In addition, we demonstrated the considerable reduction in f_L from 3.4 to 2.5 GHz and a significant increase in f_U from 9.1 to 16.2 GHz when compared with the mushroom-type EBG structure. [ABSTRACT FROM PUBLISHER]

A figure of merit for electromagnetic compatibility (EMC) testing antennas is first introduced and some design considerations are presented. A compact dipole antenna with curved reflector is proposed for 1.0–4.2 GHz EMC measurement. Structure of the curved reflector, defined by a power function, is studied by full-wave simulations and verified by experiments. A comparison between the curved reflector, corner reflector, and pyramidal reflector is presented and discussed. The presented antenna has nearly constant radiation patterns and realized gain. The minimum measurement distance is only 1.0 m for the proposed antenna, which reaches the lower limit recommended by CISPR. For small equipments under test, the measurement distance can be alternated and higher field strength can be provided by the proposed antenna without increasing the input power. In contrast, double-rigided horn antennas do not have the flexibility as they have much larger dimensions. [ABSTRACT FROM AUTHOR]

In the framework of a high-frequency transmission-line theory for nonuniform lines (TLST), new reflection and transmission coefficients are derived using generalized definitions of equivalent quantities from the classical transmission-line theory. This leads to local and frequency-dependent reflection and transmission coefficients expressed in terms of matrizant elements. These quantities are needed to describe networks of nonuniform radiating transmission lines. A comparison between the currents calculated in the approach of TLST and those calculated with the aid of the new transmission and reflection coefficients shows an excellent agreement. [ABSTRACT FROM AUTHOR]

We present a review and comparison of different models representing the frequency dependence of the soil electrical parameters (conductivity and permittivity). These models are expressed in terms of curve-fit expressions for the soil conductivity and relative permittivity, which are based on experimental data. Six available models/expressions are discussed and compared making reference to two sets of experimental data. It is shown that the soil models by Scott, Smith–Longmire, Messier, and Visacro–Alipio predict overall similar results, which are in reasonable agreement with both sets of experimental data. Differences between the soil models are found to be more significant at high frequencies and for low-resistivity soils. The causality of the considered models is tested using the Kramers–Kronig relationships. It is shown that the models/expressions of Smith–Longmire, Messier, and Portela satisfy the Kramers–Kronig relationships and thus provide causal results. The soil models are applied to the analysis of grounding systems subject to a lightning current. A full-wave computational model is adopted for the analysis. The analysis is performed considering two cases: 1) a simple horizontal grounding electrode, and 2) a realistic grounding system of a wind turbine. Two current waveforms associated with typical first and subsequent return strokes are adopted for the representation of the incident lightning current. In agreement with recent studies, simulations show that the frequency dependence of the soil parameters results in a decrease of the potential of the grounding electrode, with respect to the case where the parameters are assumed to be constant. It is found that the models/expressions by Scott, Smith–Longmire, Messier, and Visacro–Alipio predict similar levels of decrease, which vary from about 2% (\rhoLF = 20 Ω·m and first stroke) up to 45% (\rhoLF = 10 000 Ω·m and subsequent stroke). On the other hand, the models of Portela and Visacro–Portela predict significantly larger levels of the decrease, especially for very high resistivity soils. Furthermore, in the case of a high resistivity soil (10 000 Ω·m), the Visacro–Alipio expression predicts a longer risetime for the grounding potential rise, compared to the predictions of Scott, Smith–Longmire, and Messier models. [ABSTRACT FROM PUBLISHER]

The near field radiated in the common-mode excitation from single-walled carbon nanotube (SWCNT) bundles with rectangular or hexagonal cross section above a perfect conductive plane is predicted in the gigahertz frequency range using the equivalent single conductor (ESC) method. The risk of electromagnetic interference against nearby components and devices can be estimated. The computed frequency spectra and spatial distributions of the electric and magnetic fields are validated by comparison with the ones radiated from all the conductive SWCNTs in the bundle represented by the multiconductor transmission line (MTL) model. The obtained results highlight the noticeable accuracy and simplicity of the ESC approach with respect to the very time consuming MTL formulation. [ABSTRACT FROM AUTHOR]

The specific absorption rates (SARs) in 7-year-old Korean, and 5- and 9-year-old European child head models were evaluated and compared with those of the specific anthropomorphic mannequin (SAM) phantom for mobile phone exposure at 835 and 1900 MHz. Compression of the pinnae was also considered for the 5- and 7-year-old child models during the evaluation. The cheek and tilt positions occurring when the earpiece of the phone is placed at the ear entrance canal (EEC) were analyzed against the same positions occurring when the earpiece is placed at the ear reference point (ERP). SAR variations were investigated for different skin and fat properties, as well as for different internal fat and muscle morphologies in the tissue area near the phone. A basic phone model with a monopole antenna was used for SAR calculation at each frequency. A phone model with a planar inverted F antenna was also used for verification, since the SAR results in the child models were higher than those in the SAM phantom at 1900 MHz. The spatial peak 10-g SAR values in all tissue including the pinnae and head-only were normalized to a forward power of 1 W at the feedpoint of the phone. Our results can be summarized as follows. First, a compressed pinna did not show significant changes in SAR values at 835 MHz; however, at 1900 MHz, there was an average 25% increase in spatial peak 10-g SARs for pinna-excluded tissue and a 29% increase for pinna-included tissue. Second, a phone earpiece placed at the EEC provided higher SARs in many cases compared to placement at the ERP. Third, the peak 10-g SAR was found to be very sensitive to the fat and muscle structure under the skin when touched by the mobile phone; a muscle-dominant internal head structure led to a higher peak 10-g SAR. Finally, the SAM phantom does not seem to provide a conservative estimation of child head exposure at 1900 MHz; 45% (pinna-excluded: IEEE Std C95.1) and 75% (pinna-included: ICNIRP guidelines) of the 40 total cases we reviewed showed higher SAR results than the SAM phantom. [ABSTRACT FROM PUBLISHER]

An efficient analysis using the contour integral method (CIM) for the modeling of inhomogeneous substrates with circular or arbitrarily shaped dielectric inclusions in planar structures is presented. It is shown how the segmentation method is applied to obtain circuit parameters as well as field values and how different boundary conditions can be implemented. Such an analysis is especially useful for the modeling of photonic crystals power/ground layers (PCPLs) in power delivery networks (PDNs) on printed circuit boards (PCBs). For circular inclusions, an analytical solution is presented, which improves efficiency and accuracy of the proposed method. An equivalent circuit model for cylindrical inclusions is derived, in order to obtain an effective capacitance for low frequencies and an estimate for parasitic effect at higher frequencies. It is shown how circular inclusions can be compared to decoupling capacitors on a basis of impedances. The method is validated with full-wave simulations showing a reduction in simulation time of about one order of magnitude. [ABSTRACT FROM PUBLISHER]

The behavior of the ensemble averaged wave impedance computed by the rectangular field components and the impedance computed by the total field is numerically studied for a nonideal reverberation chamber. Evident departures from the medium intrinsic impedance are observed for the rectangular components when the ratio of the means and the mean of the ratios are exchanged. The power received by the antenna placed in the chamber is compared to that computed by the total field components, the rectangular field components using the wave impedance and the intrinsic impedance. [ABSTRACT FROM PUBLISHER]

The local specific absorption rate (SAR) is a critical concern of the safety in high-field magnetic resonance imaging (MRI). In order to provide rapid and subject-specific local SAR evaluation, a hybrid numerical technique that combines fast direct method of moments (MoM) and the finite-difference time-domain (FDTD) method was developed. Its validity was demonstrated by comparing with conventional numerical methods and experimental results. An example with a real human head model was further provided to demonstrate its utility. [ABSTRACT FROM PUBLISHER]

Exact formulas are here given for 1) the electromotive force induced in a circular loop antenna by a quasi-static and uniform magnetic field perpendicular to the plane of the loop, and 2) the inductance of the loop. The loop consists of one turn of perfectly conducting round wire. Formulas are general in that they are valid for any possible value of the wire radius. Comparison with the results of numerical simulations is offered in order to let the reader appreciate the degree of accuracy obtainable through computational electromagnetics modeling of this canonical problem. [ABSTRACT FROM PUBLISHER]

A multiresolution time-domain (MRTD) method is proposed for cloud-to-ground lightning electromagnetic pulse (LEMP) calculation. Scaling function of Daubechies wavelet is chosen for fields expansion, and iterative formulas of MRTD method are derivated in 2-D cylindrical coordinates. First, three double-exponential lightning channel-base current with different rise times have been used for evaluating performance of the finite-difference time-domain (FDTD) method. And then, LEMP of different distances of the lightning channel were calculated with the MRTD method. We examined the MRTD method by comparing the results obtained with the FDTD method. Numerical simulation results show that the MRTD method and FDTD method are consistent with each other for first return stroke, even with a larger grid division. However, for subsequent return stroke, oscillations will be observed in the late response of the waveforms calculated by the FDTD method. Comparing with the FDTD method, the MRTD method suffers less oscillations with the same grid division, and can significantly save both computational memory and CPU time with large gird mesh, as well as good numerical dispersion property. [ABSTRACT FROM PUBLISHER]

A new convolutional perfectly matched layer (CPML) is proposed and implemented in one-step leapfrog alternately direction-implicit finite-difference time-domain (ADI-FDTD) method. Different from the previous developed perfectly matched layers (PMLs) used in the ADI-FDTD methods, the proposed PML has the same form as that used for the conventional FDTD method, requiring only one-step computations of the CPML auxiliary quantities. Stability of the proposed CPML is verified semianalytically and its high absorption efficiency is proven numerically. The proposed CPML is then applied to a number of applications; they include radiation generated by a current source in free space, propagating and evanescent modes in a rectangular waveguide, and transient current prediction on an aircraft that is modeled with a numerical grid of 402 × 48 × 262. Accurate results have been obtained in comparison with the results obtained with the other methods. [ABSTRACT FROM AUTHOR]

Closed-form formulas are derived permitting us to evaluate the nonreproducibility of conducted emission measurements due to the imperfect realization of the artificial mains network impedance. Since this is the dominant contribution to the combined standard measurement instrumentation uncertainty, the availability of such formulas permits us to tailor the uncertainty value to the actual measurement capability of testing laboratories. Furthermore, analytical formulas provide guidance both to the technical committees involved in the standardization process, when they set tolerances on the complex impedance of coupling/decoupling networks, and to the manufacturers of instrumentation, since they have to optimize the design of the networks in order to comply with the standards specifications. The nonreproducibility error is quantified in terms of its expected value and standard uncertainty. A simple and reasonably accurate approximation of its probability density function is also obtained. A comparison with the material reported in the relevant international standards is offered in order to highlight the common and the innovative aspects of the results derived here. [ABSTRACT FROM AUTHOR]

The mixed-mode ABCD parameters are newly introduced and developed, where the definition and the connection are carefully established to have both the advantages of the mixed-mode S-parameters and the ABCD parameters, simultaneously. In addition, closed-form equations to model symmetric and asymmetric coupled transmission lines are derived. With the derived equations, the voltage transfer functions and the eye diagram of a variety of printed circuit board (PCB)-level differential interconnects are analytically attainable, which greatly enhances their applicability for signal integrity analysis. To verify the derived equations and to validate the proposed mixed-mode ABCD parameters, a series of microstrip-type differential lines on PCB test vehicles were fabricated and tested. The effectiveness of the proposed mixed-mode ABCD parameters was successfully confirmed through the comparison studies, in particular for the case of mode-conversion occurrence at the differential lines. [ABSTRACT FROM PUBLISHER]