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This paper proposes a new approach to modeling the radio frequency (RF) electromagnetic disturbances in broadband power line communication (PLC) networks using the multi-conductor transmission line (MTL) theory. The model includes a differential-mode (DM) current propagation model and a common-mode (CM) current propagation model. The frequency range of interest is from 1MHz to 30MHz. Practical measurements are carried out to compare with the simulation results as a form of verification of the accuracy of the proposed models. Published version

A novel measurement method has been developed to characterize the common-mode (CM) and differential-mode (DM) impedances of power line EMI chokes under realistic loading conditions. With a proper pre-measurement calibration process, all parasitic effects in the measurement setup can be eliminated. The measurement allows designer to assess the EMI suppression performance of these chokes with reasonable accuracy under various loading conditions. With the measurement results, a proper choke with optimum EMI suppression performance could be selected for a specific loading condition. Published version

A novel measurement method is proposed to evaluate the performance of a ferrite core on a power cord under actual operating condition. The proposed method allows the common-mode impedance of a ferrite core under in-circuit condition to be measured so that it provides a more realistic assessment of the noise suppression capability of the ferrite core. With a pre-measurement characterization process, possible error due to parasitic effects of the measurement setup can be determined and eliminated. Hence, good accuracy is achieved for the proposed measurement method. Published version

In the past only critical clock circuits are running at high speed but this is no longer true in today high-speed digital design world. Most of the digital traces on board are running at speed in excess of 200 MHz and drivers output with rise time less than 1 ns. Due to constraints of board size and highly complex designs, trace bends and inter-layer transitions through vias are unavoidable. This paper carries out a comprehensive study on the impacts of bends and ground return vias optimisation on signal integrity performance using a full-wave electromagnetic simulator. (CST Microwave Studio). This study will provide high-speed digital designers an in-depth assessment of these effects in high-speed GHz applications so that some design guides to avoid these effects can be established. Published version

A comprehensive crosstalk analysis for different layout configurations has been carried out. Using a full-wave electromagnetic simulation tool, crosstalk reduction techniques based on trace-to-trace separation, guard traces, inter-layer ground plane are studied. With the comprehensive simulated results, useful design guidelines are established so that the designers can select the appropriate layout methodology to achieve the desired level of crosstalk isolation. Published version

International audience; AC railways are characterized by peculiar Power Quality phenomena, where moving loads (trains, locomotives, etc.) inter- act with the supply network that provides electrical energy through the overhead contact line. Distortion, resonances, transients overlap in a complex dynamic scenario, that sees several and various problems of Power Quality, network stability, power and energy metering and disturbance to systems and equipment. For all related studies and analysis raw experimental data are extremely important. The provided data consists of time-domain waveforms of sampled panto- graph voltage and current: each recording is tagged with the specific train operating condition (traction, cruising/coasting, braking, standstill), the active power and the speed, to sup- port correlation and clustering of data.

A novel sensor for the detection of the lightning current through the fuselage of an aircraft has been tested on an A320 aircraft. An accurate method-of-moment model of the window edge provided reliable calibration of the sensor for external fields. The data have been analyzed and the good performance of the sensor in sensitivity and bandwidth is demonstrated.

A novel sensor is described for the detection of the lightning current through the fuselage of an aircraft. The sensor relies on the penetration of the magnetic field through fuselage openings and can be embedded in a window inside the aircraft. The sensor combines good sensitivity with sufficient bandwidth to record the lightning transient current. Guidelines for the position are derived from a mathematical analysis for a circular window.

In a recent paper (G. Bargboer and A. P. J. van Deursen, IEEE Trans. Electromagn. Compat., vol. 52, no. 3, pp. 684-90, Aug. 2010) we dealt with current injection measurements to test the lightning protection system of a newly built pharmaceutical plant. In a tentative extrapolation, the measurements were extrapolated to actual lightning. Here, we extend the model and calculate the response of the installation on lightning currents and include resonances in the cable trays and test cables contained in it. It turned out that suspension rods between roof support and cable tray were indispensable to suppress the resonances. The time dependence of the present results and the earlier simplified model given in differ greatly, but the amplitudes of induced voltages appear to be of the same order of magnitude.

The performance of metal conduits for protection of cables is investigated. An open U-shaped conduit is chosen as a basic configuration. A number of wires inside represents the actual cables with their shields. This configuration is subjected to a plane-wave excitation to determine the induced currents and voltages, which represent the common-mode signals in the cable shield. The simulated and tested object is 1.5 m long, with a cross section of $9 times 9$ cm $^2$. Results are presented for frequencies up to 1 GHz, some up to 5 GHz. Measurement and simulation results agree to within 6 dB.

A newly built pharmaceutical plant has been investigated by measurements. Currents of 0.3 kA were injected in the lightning protection grid on the roof. Inside the building, test cables of 100 m length followed a path typical for cables belonging to the installation. We measured induced cable currents and voltages. A reduced model of the building incorporated most of the designed current paths. Measurements and model showed that the roof steel skeleton carried about 80% of the current and the intended lightning conductors 20%. The calculated current through a cable support was larger than measured. This is explained by also considering a nearby nonintended conductor. For three types of cables, we determined the transfer impedances. The measurements and model have been combined and extrapolated to actual lightning.

Large-scale tests at the new Harbor Railway Line in The Netherlands asked for a dedicated measuring system for all currents at eight cross sections of the railway. The differentiating/integrating measurement scheme with adapted versions of Rogowski coils and special integrators fulfilled the requirements with respect to accuracy, bandwidth, electromagnetic compatibility, life-time, and environmental constraints. Three types of current sensors were developed; their air-core guaranteed linearity over the full current range up to 20 kA. Most importantly, the sensors allowed unimpeded rail transport. The paper discusses the sensors, the rationale, and tests, as well as the integrators. The system has been successfully employed, before and after the large-scale tests, in Luxembourg and Portugal. A few out of much data gathered show the broad applicability of the system.

A novel artificial magnetic conductor based on a low-profile implementation of a capacitively loaded resonant structure is presented, with increased performance in terms of miniaturisation. In addition, a comprehensive analysis of all the parameters involved in downsizing is provided, establishing a fair methodology for comparing the performance of different size reduction strategies.

The effect of a nearby U-shaped metal cabinet panel on the inductive common-mode coupling of a printed circuit board (PCB) is calculated in a two-dimensional (2-D) model by Schwarz-Christoffel (SC) transformations for doubly connected regions. Such an open metal cabinet can significantly reduce the mutual inductance between the microstrip lines on the PCB and the common-mode circuit if the cabinet is properly connected. But it may also increase the coupling for balanced pairs of tracks, in particular where the coupling for a single track varies strongly with position. Details of the SC approach are presented. The SC results agree with those of a static method of moments approach, but also clearly indicate the accuracy limits of the latter method.

Radio base stations are often mounted on towers of power transmission lines. They are usually powered from the low-voltage network through an isolating transformer, to separate the high- and low-voltage networks. The isolating transformer ensures security at customers' premises in the case of nearby power faults and particularly in case of lightning striking, which is a frequent cause of flashover of the high-voltage insulators and a subsequent phase-to-ground fault. To optimize such protection, a better understanding of the current distribution to the ground in the initial phase of the lightning striking is required. This work presents a computer simulation method and its results for the lightning current distribution between the sky wires, grounding systems, and power cable network. What is of special concern is the part of the lightning current that might be led into the metal-shielded distribution cable network. A rigorous electromagnetic modeling approach was applied for the analysis of the grounding effects in a network of coated and uncoated low- and medium-voltage cables. The analysis was then applied to a practical case.

Vertical ground rods have been used extensively from the early days of electrical engineering for earth termination of electrical and lightning protection systems. They are usually represented with equivalent circuits with lumped and distributed parameters based on quasistatic approximation, which limits the upper frequency of their validity domain. However, lightning-related studies often require modeling in the megahertz frequency range. Also, emerging technologies, such as power-line communications, require analysis in frequency ranges even up to a few tens of megahertz. The rigorous electromagnetic (EM) field theory approach may be used for such frequency ranges, but equivalent circuits are needed for the usual network analysis methods. In this paper, we look at possibilities to construct simple equivalent circuits that can approximate or match results from the EM model. In particular, we compare a usual homogenous distributed parameter circuit with a nonhomogenous one determined by curve matching with results from the EM model. The analysis is illustrated using numerical simulations.

Ferromagnetic materials, such as steel, are used for shielding of power and telecommunication cables. These shields often provide path for currents during faults or lightning and are important for the integrity and safety of electrical systems and devices. Since such currents might be with low- or high-frequency content, and of low or high intensity, ferromagnetic shield behavior might be quite different due to hysteresis. This paper describes a method for analyzing the dynamic behavior of ferromagnetic cable shields based on the Jiles model of hysteresis. The solution is implemented in ATP-EMTP, which allows one to analyze the complex behavior of ferromagnetic cable shields in conjunction with that of the other elements of the power system. Due to limitations of the model of hysteresis, application of the proposed model is limited to frequencies up to about 10 kHz. The model is illustrated for a practical 100-m-long cable.

Low-voltage (LV) applications mounted on high-voltage (HV) towers may pose a safety problem in the low voltage network when a flashover occurs over the high-voltage insulators. To study the effects experimentally, a 150 kV system was made available. On a high voltage tower carrying a cellular phone base station, one phase insulator was shorted to the tower. A current of about 200 A was injected into that phase at a large distance. We measured the current distribution and the relevant voltages in the low voltage net. The experimental current data agree with EMTP calculations. Appropriate measures to guarantee safety for persons and electronic equipment are discussed.

Common-mode (CM) currents on cables attached to printed circuit boards of various complexity have been measured. The boards have a continuous ground plane, with tracks on both sides. The experimental results are compared to calculations with a transmission-line (TL) model. Expressions for the coupling parameters in the TL model have been derived with conformal transformations and the method of moments. Measurements up to 1 GHz agree with the TL model, showing that this model can be used as a tool for an early EMC analysis during the lay-out and routing of a board.

Metallic conduits provide mechanical support for cables, and may also protect the cables against interference caused by currents induced by external electromagnetic fields. The conduit transfer impedance Z/sub t/ then is a good measure for the provided protection. We studied Z/sub t/ by means of conformal transformations and of the method of moments in a quasistatic, two-dimensional (2-D) approach. Practical U-, H-, L-, and T-shaped conduits are discussed. Conformal transformations provide simple engineering expressions for the mutual inductance part of Z/sub t/ for cable positions inside the conduit. The method of moments formulation results in useful approximations for the crossover frequencies in Z/sub t/ between DC and high frequency. Measurements on U-shaped conduits confirm the calculations.

Conventional field strength sensors use different detection methods, each having advantages and disadvantages. Modern signals in, for instance, wireless communication systems and radars use very complex modulation. Other signals, such as the ones often measured in reverberation chambers with mode stirring, are fast-varying with high dynamic range. Conventional probes struggle to give reliable measurement data in these situations, while the more expensive solutions based on optical-electric conversion and heterodyne receiver, are so costly that often only one component of the field is measured. The impact of conventional field strength probes when measuring (complex) modulated signals is discussed. Furthermore, this paper describes the design, fabrication, and characterization of fast, broadband, three-axis, and high-dynamic range probes. They have been designed for mapping the fast-changing electric field strength in complex electromagnetic environments such as reverberation chambers under mode-stirring operation.

This paper introduces the basic concepts and implementation of a Vibrating Intrinsic Reverberation Chamber (VIRC). This kind of chambers is used in electromagnetic compatibility testing, and offer some advantages compared to traditional chambers. An introduction, an overview of theoretical principles, a description of the VIRC recently built at the CAERCEM research center at Instituto Tecnolo´gico de Buenos Aires, and some measurements obtained during its initial characterization process are included.

Reverberation chambers create a statistical uniformly distributed field which is very useful for reliable electromagnetic interference measurements. Another advantage of these chambers is the high field strength which can be generated compared to conventional test setups. A reverberation chamber made of flexible cloth is called a vibrating intrinsic reverberation chamber (VIRC) and the field stirring is achieved by moving the (angle of) the walls. A new technique for shielding effectiveness measurements is the dual-VIRC method. In this method two VIRCs are combined together via a common wall with an aperture that forms the interface between them. This set-up makes it possible to achieve a very high dynamic range. A main advantage of this technique compared to the nested reverberation set-up is that measurements can be conducted much faster and at much lower frequency.

With rapidly growing circuit density and the demand for low power supply to ICs in high-speed printed circuit board (PCB) design, board emission issues tend to seriously deteriorate the power distribution network (PDN) on PCBs. Among a variety of proposed PDN designs and guidelines, the use of edge-mounted capacitors to suppress board emissions is validated by measurements. The results demonstrated that the edge-mounted capacitors can effectively reduce the board edge emissions from a few MHz to 1 GHz. It is believed that the capacitors' inherent equivalent series inductance (ESL) limits the suppression of PDN impedance and board emissions above 1 GHz. In this paper, the impact of ESL on the board emissions will be analyzed. Simulation results show that the ESL of the edge-mounted capacitors of a few nH still provide a low PDN impedance for the power/ground plane pair. For ESL of a few uH or larger, the capacitors cannot effectively suppress the emissions and radiation. In addition, larger ESL will bring down the first board resonant frequency of the PDN impedance from above 1 GHz to few hundred MHz. Hence, a narrower frequency band with low PDN impedance.

A tri-band frequency selective band-stop EMI shield is designed using various concentric rings with each ring resonating at the specific desired frequency. The shield is fabricated using roll-by-roll screen-printing process, making it suitable for large surface architectural shielding applications. The design is designed using full-wave simulation tool and the performance is validated experimentally.

Today's digital data lines are clocking at very high speed, in excess of 100MHz with rise time in the sub-nano second range. The effects of EMI radiation even from short traces are becoming significant and cannot be ignored. The use of resistive termination versus the EMI filter has long been a compromise in terms of cost and necessity. EMI compliance is now becoming a major design challenge for product development rather than a mere good-to-have specification of low emission. This paper carries out a comprehensive study on filter selection, application, impact on receiver waveform signal integrity and far-field emission suppression using a full-wave electromagnetic simulator (CST Microwave Studio). This study will provide high-speed digital designers an in-depth assessment of the use of EMI filter for radiation suppression in high-speed digital layout.

With increasing board complexity and operating frequencies, signal integrity (SI) and radiated emission (RE) compliance for high speed digital board is becoming a challenge to printed circuit board (PCB) designers. Together with higher routing density and multiple on-board power supplies, routing traces across split planes are unavoidable. In this paper, SI performance and RE of single ended (SE) and differential signals propagating across slots are studied. Using both experimental and numerical simulation approaches, the impacts of single ended and differential high speed digital signals across a split plane are investigated and analysed.

The introduction of 25 kV a.c. traction in the Dutch railway system required a careful study of the compatibility with existing 1500 V d.c. traction and with other systems in the vicinity of the railway. Over the last decade, a number of studies have been carried out, using specially developed measurement systems and methods of analysis. The present paper describes a newly developed Poynting sensor that builds on the earlier developed differentiating/integrating measurements system. Measurements on the railway power system with current injection at e.g. 60 and 48 Hz will be discussed as well.

This paper proposes an efficient method for simulating the radiated immunity of printed circuit board (PCB) with arbitrarily oriented traces. Existing methods usually deal with plane wave excited PCB with simple configuration, for which a SPICE model can be analytically derived. Nevertheless, it is difficult to analytically develop a SPICE model for a PCB whose traces are arbitrarily oriented. In this work, traces of a PCB are divided into small segments. SPICE model of the PCB is obtained by connecting equivalent circuits of all segments. Meanwhile, the incident field is converted to distributed current and voltage sources in the SPICE model. Radiated immunity of the PCB is then analyzed using SPICE. Since it is challenging to analyze all traces of the PCB simultaneously, uncoupled traces are individually simulated. Numerical examples are presented to illustrate the advantages of the proposed method. It is shown that the proposed method is about 17 times faster than a full wave analysis method.

This paper describes recent advancements in hybrid numerical modelling of reverberation chambers (RCs). Motivation of modelling an RC is first described, and challenges in RC modelling are pointed out. Shortcomings and advantages of conventional numerical methods are discussed, and hybrid techniques are introduced to overcome disadvantages of different numerical methods while retaining their respective strengths. Benefits of hybrid methods are then illustrated using numerical examples, and future works are finally suggested.

Electromagnetic interference (EMI) from mobile phones on hearing aids are investigated. Different operating modes of the hearing aid have different impact on the immunity of the device. An experimental study will be carried out to understand the impact of EMI filter on the compliance of the hearing aid under the operating modes.

Complex electromagnetic environments represent a difficult challenge to be tackled from the electromagnetic compatibility point of view. In such structures, the field dynamics present strong dependence on the complex and (very often) changing boundary conditions. Solving the electromagnetic field in such structures is extremely complex, making the calculation problem quickly intractable. In this work we make use of state-of-the-art statistical models already developed for the study of reverberation chambers. The assumption is that an imperfectly-performing reverberation chamber works statistically analogous to a semi-reverberant complex structure. Various configurations of reverberation chambers can be easily implemented in practice. In this sense, reverberation chambers have the main advantage to act as laboratory-controlled electromagnetic environments, being able to mimic real-life complex enclosures.

In this paper, the out-of-band characteristics of the airborne blade antennas are studied in terms of their gain and radiation properties. A prediction model was derived for both the lower out-of-band and upper out-of-band frequencies of a typical blade antenna.

The lightning protection of a pharmaceutical plant has been tested by current-injection on the structure. The study aims at two goals: 1) proof of safety by scaling the currents and voltage to lightning realistic values and 2) a comparison between measurements and a Method of Moments calculation. We measured the current distribution near the source and the induced currents and voltages in test cables. The cables and their 100 m long path were representative for the actual installation. By necessity the model is simplified, because of the large number of conductors, intended and unintended, and the uncertainty of their interconnection. The calculated currents are a factor of 3 larger than measured. © 2009 IEEE.

Lightning strikes a commercial airliner on the average once a year. The European project ldquoIn-flight Lightning Strike Damage Assessment System (ILDAS)rdquo [1] aims to develop and validate a prototype of a system capable to 1) reconstruct the current intensity and wave form, 2) determine of the region of impact on the aircraft, 3) build a maintenance database. Suitable sensors rely on determination of the magnetic field during a strike. Probes considered are inductive coils and solid state sensors, combined in such a way that these cover the full dynamic range in amplitudes (1 A/m up to 40 kA/m) and the full bandwidth (approx. 1 Hz up to 20 MHz). External sensors should be avoided if possible.

Commercial passenger aircraft are on average struck by lightning once a year. The in-flight lightning strike damage assessment system (ILDAS) project is to develop and validate a prototype of a system capable of in-flight measurement of the current waveform and reconstruction of the path of lightning current. This paper discusses the various magnetic sensors, their rationale and some tests. Inductive sensors require an integrator in the signal conditioning. Much attention has been paid to the passive integrator, which is the first integrator stage preliminarily responsible for EMC.

Cellular phone base stations are often placed in the poles of power transmission lines. We consider the case when such base stations are powered from the low-voltage network. Of special concern is the current that might be led through the cable metallic shields to other customers' premises in case of lightning stroke, which is a frequent cause of flashover of the high-voltage insulators and a subsequent phase to ground fault. This paper presents an analysis in the frequency domain of the lightning current distribution between the earth wires, grounding systems and power cable network, in case of lightning stroke at the tower. The models and the analysis are applied to a practical case

In spite of large amount of research work in the last decades on the grounding systems modeling for high frequencies and transients there is no consensus on its practica applicability. This work points to some issues that may be important in the systematic approach to determine the validity domains of the different existing methods for analysis. In particular, the following topics are discussed: the evaluation of the upper frequency of interest in the transient study, the limitations due to the electrical dimensions of the system, and due to the underlying circuit concepts, especially in relation to the definition of impedance to ground. As a basis for the evaluation of the validity domains of more simplified quasi-static and circuit based models a full-wave electromagnetic model is described. Validation by comparison with experiment and illustrative numerical results are presented.

Metallic trays and conduits protect bundles of cables in electrotechnical installations by diversion of interference currents. The relevant parameter is the conduit transfer impedance Z/sub i/. Conformal transformations yield the inductive part M of Z/sub i/ for conduits with noncontacting covers. Analytical approximations for M agree well with measurements.

The analysis of the dynamic behavior of power transmission line and telecommunication towers is of interest in protection and EMC studies related to lightning. Usually, time-domain surge impedance is used to characterize tower dynamic behavior. The main drawback in the definition of such surge impedance is that it is dependent on the excitation waveshape and there is no consensus on the current waveshape to be used. Also, there is no consensus on the unique definition of the involved voltage. This paper explores possibilities for a systematized approach to the analysis and uniquely defined quantities that characterize transient response of towers. Further, limitations associated with simplified approaches are emphasized by examining examples of direct comparison between computations based on transmission-line approach and antenna theory for a 100-m tall tower. It is pointed out that problems in the definition of voltages might occur above 100 kHz, especially near resonant frequencies, while differences in current distribution exist already at the lowest frequencies.

This paper aims at proving the application of the fault location method based on the Electromagnetic Time Reversal (EMTR) to multi-terminal HVDC (MTDC) networks. In particular, the paper integrates the EMTR fault location technique with the protection scheme recently proposed within the EU project TWENTIES. Further, in view of the peculiarity of the fast protection schemes required by HVDC applications, the paper discusses the performances of the EMTR-based fault location technique by using limited time-windows over which the fault-generated electromagnetic transients are time-reversed. The paper also discusses the advantage of the EMTR fault location related to the use of a single observation point to the case of MTDC grids. Indeed, such a peculiarity may represent a major advantage avoiding necessary time synchronization between the MTDC-fault recording stations and might represents, also, a backup protection system. The performances of the proposed method are validated by numerical simulations obtained using the EMTP-RV simulation environment where electromagnetic fault-transients are reproduced with reference to the MTDC benchmark network of the project TWENTIES.