Showing papers on "Electromagnetic compatibility published in 2013"

Implementation of a Novel Digital Active EMI Technique in a DSP-Based DC–DC Digital Controller Used in Electric Vehicle (EV)

Abstract: With ever increasing green-house gas emissions from fossil fuel-driven automobiles leading to acute environmental pollution, and ever depleting reserves of fossil fuel, today need for the development of pure electric vehicle (EV) is of utmost importance. Presently, there is an immense impetus to develop plug-in EVs. High switching frequency and high-power ac-dc PFC converter with an isolated output and a dc-dc isolated converter are essential systems for transferring from utility mains to the different battery packs which store energy for propelling the EVs. Electromagnetic compatibility (EMC) with strict regulatory standards is an essential requirement which any switch mode power converter must comply with not only for its own operation but also for safe and secure operation of surrounding electrical equipment. EVs possess many sophisticated electronic circuits in the vicinity of the battery charging power converters, so strict EMC standards of the on-board power converters should be met. For a cost-effective design approach, EMC should be considered at the primitive stages of the power converter design. The most commonly used passive electromagnetic interference (EMI) filters used for EMI mitigation in power converters come at the expense of cost, size and weight, power losses, and printed circuit board (PCB) real estate. In this paper, a novel embedded digital active EMI filter (DAEF) integrated into the DSP-based digital controller of a dc-dc converter applicable for charging the low-voltage battery bank of an EV is proposed and analyzed. Experimental results and comparison of the performance of the proposed embedded DAEF with a conventional EMI filter are presented in this paper so as to validate the feasibility of the proposed EMI filter and its advantages over the conventional one.

A High Frequency Equivalent Circuit and Parameter Extraction Procedure for Common Mode Choke in the EMI Filter

Abstract: Power converters with high switching frequency generate conducted electromagnetic interference (EMI) noise. EMI filters are thus widely used to reduce these conducted noises for the compliance with electromagnetic compatibility standards. In this paper, a high-frequency (HF) equivalent circuit model for common mode (CM) chokes used in EMI filters is proposed together with its parameter extraction procedure. This procedure is based on impedance measurements and it incorporates an iterative rational function approximation fitting algorithm to extract the parameters in the model. The proposed model and procedure is applied to a planar CM choke which is used to realize an EMI filter. The simulated results of the filter show good agreement with the experimental ones. This extraction procedure is quite general and it can also be extended to identify the HF model of other passive components.

Effective Permittivity of Shielding Composite Materials for Microwave Frequencies

Abstract: Due to mass constraints, composite materials are possible candidates to replace metal alloys for electromagnetic shielding applications. The design of standard metallic shielding enclosures often relies on finite-element calculations. But in the case of composite materials, the strong dependence on the shielding properties to the microstructure makes the finite-element approach almost impossible. Indeed meshing the microstructure would imply a huge number of elements, incompatible with usual computational resources. We propose in this paper to develop homogenization tools to define the effective electromagnetic properties of composite materials at microwave frequencies. The ratio between the characteristic size of the microstructure and the wavelength is shown to be a key parameter in the homogenization process. The effective properties can then be used as an input for electromagnetic compatibility standard tools, designed for homogeneous media.

Determination of the impact indicators of electromagnetic interferences on computer information systems

Abstract: The present article covers an influence of the impact of electromagnetic interferences on computer information systems whose purpose is to control transport supervision systems. The primary objective of transport supervision systems is to detect hazards to human life and health that occur in the process of transport: traveling of people and/or cargos. This process needs to be characterized by a high level of reliability and safety. The measure of the transport safety is the confidence that the elements of a transport process will remain intact during its realization with the exception of those changes that are the result of the natural processes of aging and wear. The railway environment is one of the most difficult environments concerning the provision of electromagnetic compatibility. Those electromagnetic interferences that are intended and not intended being generated in a rail area have an impact on the operation process of a transport supervision system.

Electromagnetic compatibility in railways

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Generalized Ray Theory for Time-Domain Electromagnetic Fields in Horizontally Layered Media

Abstract: Generalized-ray theory for time-domain electromagnetic fields in a horizontally layered medium is developed. It can be considered as the time-domain equivalent of the intensively studied Green's function formulation in frequency domain. After introducing appropriate integral transformations and source-type field representations, the solution is written out in terms of generalized ray constituents whose space-time counterparts are constructed with the aid of the Cagniard–DeHoop technique. The formulation lays the foundation to rigorously study time-domain field behavior in numerous practical topologies where a stratified multilayer is involved, such as planar antennas and circuits, but also electromagnetic compatibility (EMC) and propagation problems. Illustrative numerical results are presented.

Wideband Impedance Model for Coaxial Through-Silicon Vias in 3-D Integration

Abstract: Coaxial through-silicon via (TSV) is a promising 3-D integration solution, which can offer lower coupling with its surrounding environment and achieve better electromagnetic compatibility and signal integrity than other TSV structures. In this paper, an analytical wideband equivalent circuit model is proposed for the impedance modeling of coaxial TSVs in 3-D integration. Closed-form formulas for calculations of the per-unit-length resistance and the inductance of both the isolation dielectric filled and silicon filled coaxial TSVs are derived from the theory of quasi-magnetostatic fields. These formulas appropriately capture the skin effect in metal as well as the eddy current effect in silicon. Therefore, they yield accurate results comparable with the full-wave solutions in a wideband frequency range.

Influence of a traction battery's input impedance on conducted emissions of an automotive HV inverter

Abstract: At present, electric traction systems are introduced into automotive applications. The driving power is transmitted via cables, which are routed close to various communication, sensor or control units. Ensuring the electromagnetic compatibility (EMC) of these miscellaneous systems within the electric vehicle is a new challenge for the developing engineers. Line filters are a very effective EMC measure, but a time-consuming and ineffective trial-and-error approach can only be avoided if the input and output impedances of the filters are characterized and known. This paper characterizes the impedance situation for a line filter within a high voltage traction system. It is intended to reduce the conducted emissions of a power inverter for a hybrid driven car. Therefore, the inverter's common and differential mode input impedances are determined. The tested device is modeled as a voltage source combined with an inverter emulating network of concentrated elements. Verifying measurements show that the inverter's EMC performance can be reproduced with the presented inverter emulation. The influence of the changed impedance situation on the attenuation of a first-order low-pass filter is shown by emission measurements.

Electromagnetic Field Coupling to a Thin Wire Located Symmetrically Inside a Rectangular Enclosure

Abstract: This paper calculates the current in a conductor inside a cavity, which is induced by lumped and distributed sources. The current is obtained both analytically (Green's function method) and numerically (multilevel fast multipole method). A long parallel wire is chosen that connects two opposite walls of a rectangular resonator. Since the conductor preserves the translational symmetry of the resonator in one principal direction, the current and the total exciting electrical field can be derived from spatial Fourier series formulations. The obtained results clearly show the influence of the walls on the induced current. Resonance peaks of the resonator, which do not arise in normal electromagnetic compatibility laboratory tests, occurred in the current spectra. The numerical results agree very well with the analytical ones; however, the results are obtained much faster using the analytical formulae (by a factor of 1000).

AC/DC/DC Interfaces for V2G Applications—EMC Issues

Abstract: Presented in this paper are the results of research connected with common mode (CM) interference generated by ac/dc/dc power electronic interfaces, which will very probably be commonly used in the future vehicle-to-grid systems. The results obtained show that the conducted CM interference generated by these converters in a low-voltage grid can be coupled to a medium-voltage (MV) network and observed at distant points under overhead MV lines. The developed passive CM voltage compensator dedicated for ac/dc/dc interfaces is recommended as an effective method for conducted interference reduction, preventing both aggregation and flow of interference in distant circuits.

Physics-Based Modeling of Power Converters From Finite Element Electromagnetic Field Computations

Abstract: In this paper, a physics-based high-frequency (HF) model of switching power converters including the insulated gate bipolar transistor (IGBT) unit cells, heat sink, and connective printed circuit board (PCB) traces combined in a single electrical circuit is presented. The IGBT model includes the HF stray components superimposed on the well-known Hefner IGBT model. The HF components were calculated using a 3-D quasi-static finite element (3-D FE) analysis. The proposed complex model of the IGBT was verified both numerically and experimentally at different switching frequencies. The computed IGBT model was used in a low-high frequency model of a motor-drive system, and the common mode ground current was experimentally verified showing excellent results.

Modeling of the near-field electromagnetic radiation of power cables in automotives or aeronautics

Abstract: This paper presents an analytical method to compute at low simulation cost the electromagnetic near-field emitted by common mode currents in power cables supplied by power converters in automotive or aeronautics. Various cable configurations are considered: single, double or triple strand. A specific experimental bench has been built in order to verify the validity of our predictions. We show that the method enables to characterize the level of radiation of a cable versus a specific standard and that it is possible to optimize its shielding in order to minimize its weight while keeping a satisfactory efficiency.

Electromagnetic Radiation Resulting From PCB/High-Density Connector Interfaces

Abstract: Professor Clayton Paul made many contributions to the field of electromagnetic compatibility as a researcher, teacher, and mentor Among these contributions, he provided a seminal push in characterizing, understanding, and quantifying the coupling and radiation physics of electromagnetic interference (EMI) An overview of these original contributions that were driven by industry problems and needs is given here His work emphasized physics and formulation in order to provide quantitative solutions and design directions These ideas are applied to a current industry challenge in understanding and quantifying EMI that results at the interface between high-speed, high-density connectors and printed circuit boards

Space-Frequency Analysis and Experimental Measurement of Magnetic Field Emissions Radiated by High-Speed Railway Systems

Abstract: This paper shows that in the radiated emission spectrum of high-speed railway systems, a low-frequency range exists in which the magnetic field space-frequency distribution is determined, to a large extent, by the railway infrastructure features. To prove this, electromagnetic modeling of a suitably long stretch of the railway infrastructure is developed, and an ad hoc experimental campaign is carried out for comparison. Modeling and experimental measurements refer to a 50 km stretch of the Italian 2 × 25 kV ac railway system. Infrastructure simulation is obtained by resorting to a simplified approach based on multiconductor transmission line. To this end, short segments of uniform lines are cascade-connected with lumped networks representing equipment and electrical devices placed along the line, and the radiated magnetic field is evaluated from the corresponding noise-current distributions. Since the emission source, i.e., the train, has unknown electrical properties, it is represented as a unit-current source. Thus, the proposed model provides a transfer ratio between the radiated magnetic field and the current source. As a result, the maximum values of train current corresponding to magnetic field limits provided by the International Standards can be readily derived. An optimized measurement procedure is used to show that in the frequency band 60-120 kHz, transient emissions due to random and unpredictable phenomena are negligible. In such a frequency range, where continuous and persistent emissions are present, the structure of time-frequency measurement data is readily explained, and the role of the railway infrastructure on the radiated magnetic field is unambiguously identified.

A New ANN-Based Modeling Approach for Rapid EMI/EMC Analysis of PCB and Shielding Enclosures

Abstract: This paper introduces a new artificial neural networks (ANNs)-based reverse-modeling approach for efficient electromagnetic compatibility (EMC) analysis of printed circuit boards (PCBs) and shielding enclosures. The proposed approach improves the accuracy of conventional or standard neural models by reversing the input-output variables in a systematic manner, while keeping the model structures simple relative to complex knowledge-based ANNs (e.g., KBNNs). The approach facilitates accurate and fast neural network modeling of realistic EMC scenarios where training data are expensive and sparse. To establish accuracy, efficiency, and feasibility of the proposed reverse-modeling approach, PCB structures such as perforated surface-mount shields and partially shielded PCB traces are treated as proof-of-concept examples. Although the modeling examples presented in the paper are based on training data from EM simulations, the approach is generic and hence valid for EMC modeling based on the measurement data. The approach is particularly useful in the electronic manufacturing industry where PCB layouts are frequently reused with minor modifications to the existing time-tested designs.

Classification of Transient EM Noises Depending on their Effect on the Quality of GSM-R Reception

Abstract: The Global System for Mobile communications - Railways (GSM-R) is being deployed in different countries to develop an efficient communication-based train control (CBTC) system. GSM-R participates to achieve railways interoperability, replacing noninteroperable CBTC on existing networks and, thus, facilitating cross-border train circulations. GSM-R ensures voice and data transmissions between trains and control centers and also between trains. As any radio equipment, it is subject to electromagnetic (EM) disturbances present in the railway environment. Therefore, the quality of GSM-R transmissions can deteriorate. It is then important to evaluate and predict the effect of these disturbances in order to avoid any loss of train operational capacity. After an overview of the methods used for the characterization of the EM environment, we describe the GSM-R and the EM disturbances that can affect its operation. The reasons why the existing characterization methods are not fully adapted to the GSM-R are highlighted. The general principle of classification is briefly recalled. The rest of this paper develops the methodology proposed to perform the classification of transient EM noises and the presentation of a test bench and its associated experimental results. Finally, an application to an add-on electromagnetic compatibility supervising equipment installed on board the train is described.

Analytic Iterative Solution of Electromagnetic Pulse Coupling to Multiconductor Transmission Lines

Abstract: This paper provides an efficient iterative solution in the frequency domain for electromagnetic pulse (EMP) radiated field coupling to multiconductor transmission lines (MTLs) based on distributed analytical representation of the exciting sources and iterative technique originated from waveform relaxation. The method consists of two kinds of iterations, the first is that the incoming EMP wave couples to each conductor while the effects of neighboring conductors were neglected; the second is that each conductor will be not only subject to the illumination of the EMP wave, but also influenced by the virtual sources which are the induced voltages and currents of the neighboring conductors at the previous iteration. The key highlights of the proposed method are that the induced voltage and current at each iteration are considered as the virtual distributed exciting sources for next iteration, and the integrals were solved analytically by the Baum-Liu-Tesche equation, leading to a pretty good efficiency and quick convergence for most real cases. The validation results over a wide range show that the proposed method could efficiently handle EMP coupling to MTLs with a large number of conductors and the accuracy of the solutions is closely related to the number of iterations allowing the flexibility to choose between the accuracy and the time cost.

New Approach of Electromagnetic Fields of the Lightning Discharge

Abstract: Despite the significant developments in the protection means of electrical and electronic systems against the lightning and its effects. With its unpredictability and aggress if character, the lightning is the most dangerous phenomenon for electrical systems, which requires more interest and greater effort by researchers and designers means of protection. We present in this study a new analytic model of transient electromagnetic fields radiated by the lightning channel. To better estimate our new model, we developed a program "SIMLIGHTINING" with Matlab to simulated and approved all mathematic components proposed in this study. The results obtained were compared with other simulations and experiment already published have given a very appreciable similar and affinity.

Analysis of Radiated EMI and Noise Propagation in Three-Phase Inverter System Operating Under Different Switching Patterns

Abstract: In this paper, a numerical model using the finite-element (FE) method was used to predict the electromagnetic interference (EMI) generated by 325-V, 5-kW power inverter, supplying a variable three-phase load. A comparative analysis was performed to evaluate the effects of different switching patterns on the radiated and conducted EMI levels. An experimental setup was arranged to validate the simulation results. The proposed approach is suitable for prediction of radiated and conducted EMI generated by power converters. This helps reduce the post prototype EMC testing cost by minimizing redesign and modifications of final converter product.

Time-Domain Characterization of the Surge, EFT/Burst, and ESD Measurement Systems

Abstract: A simple, well-established (although in applications different from electromagnetic compatibility), amenable to direct interpretation, and inexpensive method for the time-domain characterization of the measurement systems used for the calibration of the standard impulse generators for immunity tests is presented. The validity and general applicability of the method is demonstrated through an extensive experimental investigation.

A Review on BaxSr1-xFe12O19 Hexagonal Ferrites for use in Electronic Devices

Abstract: The Ferrite term is used to refer to all magnetic oxides containing iron as major metallic component which has great to technological applications because of their ferromagnetic and insulating properties at room temperature. Among such ferrites, the hexagonal ones (hexaferrites) have long been used for permanent magnets and are of interest for microwave applications. The hexaferrite M-type has a structure built up from the S blocks interposed by the R block and are symbolically described as RSR*S*. In the last decades there has been great interest in the hexaferrites M-Type for applications as electronic components for mobile and wireless communications at microwave/GHz frequencies, electromagnetic wave absorbers for electromagnetic compatibility (EMC), radar absorting material (RAM) and stealth technologies and as composite materials. This review aimed study the structure, magnetic and dielectric properties of the hexaferrite BaxSr1-xFe12O19, which is a promising material for electronic devices and for small dielectric resonator antennas (MRA).The outline of this Review Paper is as follows:

New Behavioral Modeling of EMI for DC Motors Applied to EMC Characterization

Abstract: This paper is dealing with the characterization of the electromagnetic compatibility of the direct current (dc) motors. It acts as the complements of the works achieved recently for the modeling of dc motor impedances. The contact mechanisms between the brushes and the collector blades which cause the electromagnetic interferences (EMIs) are explained and modeled. Knowing the operating conditions of the current intensity, voltage, and speed, EMIs are measured and analyzed in radio frequencies from 100 kHz to 108 MHz. The behavioral model proposed is based on Norton's equivalent circuit where the motor is assumed as a current generator representing the EMI source, associated in parallel with its impedance model. Specific identification methods are used to quantify the EMI model parameters. It is shown that the model is in good correlation with the measurement. The model was applied for estimating the conducted EMI generated by a dc motor with its filters, and then, validations with different dc motors were performed.

A New Method for Identifying Electromagnetic Radiation Sources Using Backpropagation Neural Network

Abstract: Artificial neural networks (ANN) have been widely applied for their intelligence in pattern recognition and microwave components. For an electromagnetic (EM) radiated noise source involving EM compatibility issues, however, only Missouri-Rolla University utilized the ANN to identify EM radiated noise source types based on their different frequencies. In this study, a new method was proposed to identify EM radiated noise sources by using their spatial characteristics as unique parameters for the ANN, which is available even though radiated noise source frequencies overlap. A 3-D receiver array is used to collect the spatial characteristics of radiated noise sources. By training with 60 000 datasets, the network can identify the radiated noise source type within a few minutes with an accuracy as high as 99.98%. The influences on identification accuracy from different parameters, such as ambient noise, interval between neighboring receivers, distance between receiver array and radiated noise sources, moving steps of receiver array, training data number are discussed in detail. This method can be used in EM interference diagnostics and radio monitoring with high speed and accuracy.

Effects of LED lamps on the power-line communications channel

Abstract: LED (Light Emitting Diode) lamps have recently come on to the market as energy efficient alternatives to incandescent light bulbs. Although energy effective, they inject conductive noise into the power-line system. This can have a detrimental effect on the power-line communications channel. This paper investigates these effects when LED lamps are seen as noise sources on the power line. It shows that there are two classes of LED lamps - depending on the noise generating electronics used as drivers for the light emitting diodes. Different driver electronics have different influences in different parts of the emission spectrum. It is shown that in the CENELEC band: (3kHz-150kHz) the interference level from LED lamps is significantly below the allowed maximum PLC signal levels. In the band 150kHz-30MHz however, PLC signals compete with Electromagnetic Compatibility (EMC) levels and the SNR can be equal to zero, but only if the lamps have active power electronic converters.

Practical EBG application to multilayer PCB: impact on signal integrity

Abstract: In this paper, signal transmission performance of single ended and differential striplines between two parallel GND planes with embedded electromagnetic band gap (EBG) structure for noise isolation in high speed digital printed circuit boards (PCB) are studied. The performances in terms of |S11|, |S21|, |Sdd21| and |Scc21| are considered in function of the stack up cross section and position above the EBG. Practical considerations for the layout strategies are drawn.

On the Electromagnetic Susceptibility of Hot Wire-Based Electroexplosive Devices to RF Sources

Abstract: We present an analysis of the thermal response of a hot-wire electroexplosive device (EED) excited with different transient signals. First-order and second-order analytical models to calculate the thermal response of an EED are assessed taking as reference numerical simulations obtained using ANSYS. For the early-time response, when the time is much smaller than the thermal constant of the EED, the best approach corresponds to a first-order differential model in which the thermal capacitance is calculated with short-pulse excitations. A linear simplification to calculate the maximum temperature due to short excitations is also shown to be adequate. On the other hand, the most appropriate model for the late-time response is a second-order model. The models are used to assess the electromagnetic susceptibility of a wired EED for different electromagnetic pulsed environments. Radiated signals produced by a mesoband radiator, two types of radars, and a hyperband radiator are considered. The radar signal proved to be the most disturbing source because of its highest duty cycle and its flat spectral response around a specific frequency. Even the temperature firing threshold can be exceeded with the radiated field produced by a radar of 200 kW of output power located at a distance of 5 m.

Electromagnetic compatibility issues of dual active bridge DC-DC converter

Abstract: This paper addresses the electromagnetic compatibility (EMC) issues of high power dual active bridge (DAB) DC-DC converter, meant for aerospace applications, and discusses measures to improve its EMC capability. The paper comments on standard design practices and also offers design suggestions to suppress the EMI noise in order to facilitate an EMC compliant DAB converter design. A comprehensive set of experimental results are provided to support the discussions.

Ground test method for full-aircraft electromagnetic compatibility of commercial aircraft

Abstract: The invention discloses a ground test method for full-aircraft electromagnetic compatibility of a commercial aircraft. The ground test method comprises the following steps: 1, determining the ground test content of the full-aircraft electromagnetic compatibility of the commercial aircraft; 2, specifying reference paper of the ground test basis of the full-aircraft electromagnetic compatibility of the commercial aircraft; 3, classifying regional electromagnetic environments installed in onboard electronic and electrical equipment; 4, determining a limiting value of electromagnetic compatibility test data, the conducted emission acceptability limit of a cable and the radiated emission electric field intensity acceptability limit of each space; 5, determining and researching an electromagnetic compatibility test system; 6, acquiring a curve that the electric field intensities of electromagnetic environments of a test field are changed along with frequencies; 7, performing conducted emission measurement; 8, performing radiated emission measurement; and 9, performing front door coupling interference measurement. According to the ground test method for the full-aircraft electromagnetic compatibility of the commercial aircraft disclosed by the invention, the problems of aircraft electromagnetic environment classification and test part selection, full-aircraft electromagnetic interference test data criterion setting and quantitative test can be solved. The ground test method for the full-aircraft electromagnetic compatibility of the commercial aircraft is applied to analyze and determine whether a commercial aircraft developed machine meets the electromagnetic compatibility requirement and the airworthiness conformity requirement.

Electromagnetic transmission device, power amplification device, and electromagnetic transmission system

Abstract: In order to obtain an electromagnetic transmission device and an electromagnetic transmission system that emit high-power continuous microwaves stably onto a material or an irradiation target in electromagnetic heating systems and electromagnetic power transmission systems that are required to emit electromagnetic waves such as high-power microwaves, the electromagnetic transmission device, the power amplification device, and the electromagnetic transmission system emit, onto an irradiation target, electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle, or electromagnetic waves that are modulated by a repeating pulse with a predetermined transmission duty cycle and are amplified.