Sources Of Electromagnetic Interference Research Articles

Electromagnetic Disturbance Source Modeling Scheme and its Interference Estimation of Medium–Low-Speed Maglev Train Interior

Magnetic fields from the linear motor, suspended electromagnet, and collector shoe arcing are the three main electromagnetic interference (EMI) sources for the medium–low-speed maglev train interior. Under their collective influence, the field intensity may exceed the standard threshold, consequently affecting the operational reliability of the train system. However, in previous studies, the EMI sources were analyzed separately, and studies regarding the influence of factors such as the motor states and the train body (TB) shielding against arcing EMI were lacking. Therefore, in this paper, all three EMI source are considered, and an EM disturbance source modeling scheme is proposed using the COMSOL software platform. Its effectiveness is demonstrated and the train interior magnetic field is analyzed, primarily with respect to prior simulations and tests. Subsequent analyses enable a comparative assessment of the individual contributions of each EMI source to the overall interference, considering the EMI control standards. The influence of other EMI source parameters, such as different motor states, is analyzed, and the potential for modifying the material composition and structural thickness of the TB is explored to determine the appropriate EMI inhibition strategy.

Electromagnetic compatibility study of acoustoelectric logging detector

Abstract The acoustoelectric effect logging detector can achieve downhole acoustoelectric effect measurement, but the excitation of the acoustic transducer can generate significant electromagnetic interference (EMI) signals, it is difficult to effectively measure weak converted signals of acoustoelectric effect underground. The EMI problem of acoustoelectric effect logging detectors can be solved by studying EMI characteristics. Based on the analysis of the structure, measurement function, and measured interference signals of the receiving electrodes of the detector, the EMI sources, coupling paths, and sensitive components in the detector were studied. The basic process of EMI generated by high-voltage pulse excitation source of acoustic transducer is analysed, and two electromagnetic coupling interference analysis models for detectors, namely conductive coupling and borehole electromagnetic coupling, are established. This study can provide a fundamental method and reference for electromagnetic compatibility analysis of acoustoelectric effect logging detectors.

Прогнозирование помех электростатического разряда в электронном устройстве с использованием искусственной нейронной сети

Electrostatic discharge is a dangerous source of natural electromagnetic interference to the operation of modern electronic devices. Although measures have been taken to reduce and remove electrostatic discharge from the operating area of electronic devices, the absence of such discharge cannot be guaranteed. Therefore, when designing modern electronic devices, it is necessary to take into account the possibility of such electrostatic discharges in advance and take protective measures. The article proposes a method for predicting the amplitude of interference in the communication line of an electronic device when exposed to an electrostatic discharge on its metal case. The technique is based on the use of an artificial neural network. The technique includes the analysis of significant input parameters that affect the amount of interference in an electronic device; development of an experimental stand for measuring interference; choosing the structure and parameters of a neural network for predicting interference; choosing a training method for an artificial neural network; choosing a metric for assessing the quality of training; normalization of training data; training an artificial neural network using experimental noise data; predicting the amplitude of interference in the communication line of an electronic device when exposed to an electrostatic discharge on its body; where necessary, selecting and implementing electrostatic discharge protection measures. Examples of training an artificial neural network based on experimental data are given. The training was carried out for 572 epochs. For the training and testing sets, the discrepancy between the predicted data and the average measured noise values was 3.61% and 3.95%, respectively. Examples are given of predicting the amplitude of interference when exposed to electrostatic discharge. The results obtained indicate the possibility of practical use of an artificial neural network to solve problems of electromagnetic interference analysis.

Modeling and Analysis of Environmental Electromagnetic Interference in Multiple-Channel Neural Recording Systems for High Common-Mode Interference Rejection Performance.

Environmental electromagnetic interference (EMI) has always been a major interference source for multiple-channel neural recording systems, and little theoretical work has been attempted to address it. In this paper, equivalent circuit models are proposed to model both electromagnetic interference sources and neural signals in such systems, and analysis has been performed to generate the design guidelines for neural probes and the subsequent recording circuit towards higher common-mode interference (CMI) rejection performance while maintaining the recorded neural action potential (AP) signal quality. In vivo animal experiments with a configurable 32-channel neural recording system are carried out to validate the proposed models and design guidelines. The results show the power spectral density (PSD) of environmental 50 Hz EMI interference is reduced by three orders from 4.43 × 10-3 V2/Hz to 4.04 × 10-6 V2/Hz without affecting the recorded AP signal quality in an unshielded experiment environment.

Several Aspects of Human Exposure to Low Frequency Fields; Incident and Internal Field Dosimetry Procedures and Related Legal issues

The paper deals with simple and efficient dosimetry procedures for human exposure to low frequency (LF) electric and magnetic fields at single and multiple frequencies, respectively. The electromagnetic interference (EMI) sources of interest are overhead power lines and transmission substations. Electric and magnetic fields due to EMI sources are either calculated or measured. Theoretical dosimetry is based on scalar potential integral equation (SPIE) for the case of the electric field assessment while the magnetic fields are computed by means of the Biot-Savart law. The internal fields in the human body are determined by using the canonical body models (disk model and cylindrical model). The obtained results are compared to exposure limits proposed by national and international legislation, respectively (National Gazette No 146/2014, 31/2019, 59/2016) and ICNIRP International Commission on Nonionizing Radiation protection). Finally, legal issues pertaining to human exposure to LF fields are addressed.

Electromagnetic force from electric vehicles: Potential electromagnetic interference source for subcutaneous implantable defibrillator.

Electromagnetic interference (EMI) encompasses electromagnetic field signals that can be detected by a device's circuitry, potentially resulting in adverse effects such as inaccurate sensing, pacing, device mode switching, and defibrillation. EMI may impact the functioning of Cardiac Implantable Electronic Devices (CIEDs) and lead to inappropriate therapy. An experimental measuring device, a loop antenna mimicking the implantable cardioverted defibrillator (ICD) antenna, was developed, and validated at the US Food and Drug Administration (FDA) and sent to Wright State University for testing. Two sets of measurements were conducted while the vehicle was connected to a 220-Volt outlet with charging at ON and OFF. Each measurement set involved three readings at various locations, with the antenna oriented in three different positions to account for diverse patient postures. The experiment utilized a Tesla Model 3 electric vehicle (EV), assessing scenarios both inside and outside the car, including the driver's seat, driver's seat floor, passenger's seat, rear seat, rear seat floor, cup holder, charging port (car), and near the charging station. The detected voltage (max 400 to 504 millivolts) around the cup holder inside the car differed from all other measurement scenarios. The investigation highlights the identification of EMI signals originating from an EV) that could potentially interrupt the functionality of a Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD). These signals fell within the R-wave Spectrum of 30-300Hz. Further in-vivo studies are essential to determine accurately the level of interference between S-ICDs and EMI from Electric Vehicles.

Spatiotemporal energy‐density distribution of time‐reversed electromagnetic fields

AbstractTime reversal exploits the invariance of electromagnetic wave propagation in reciprocal and lossless media to localize radiating sources. Time‐reversed measurements are back‐propagated in a simulated domain and converge to the unknown source location. The focusing time (i.e. the simulation instant at which the fields converge to the source location) and the source location can be identified using field maxima, entropy, time kurtosis, and space kurtosis. This paper analyses the spatial energy‐density distribution of time‐reversed electromagnetic fields by introducing a convergence metric based on the spatial average and variance of the energy density. It is analytically proven that the proposed metric identifies the focusing time and the source location, with direct links to the source frequency content. The analytical results are verified in a free‐space numerical simulation and the proposed metric is then compared to existing ones in a simulated inhomogeneous medium. Next, this metric is applied and compared in an experimental case study to localize electromagnetic interference sources. The proposed metric outperforms existing ones to identify the focusing time and can also be used to locate the source. Finally, because of its tensorial nature, it can handle anisotropic media, opening the door to quantitative analyses of time‐reversal focusing in metamaterials.

Experimental electromagnetic compatibility of conducted electromagnetic interferences from an IGBT and a MOSFET in the power supply

Introduction. Most electromagnetic compatibility studies carried out in the context of power switch research are generally valid for low frequencies. This frequency restriction appears to be too restrictive for a complete analysis of the electromagnetic interference conducted. The novelty of this work lies in the load-dependent an optimal selection of IGBTs and MOSFETs for least-disturbance power switching in the frequency range from 150 kHz to 30 MHz, based on an optimal experimental selection procedure and show the impact of load value on switch switching and noise generation. Purpose. Analysis of the fundamental possibility of selecting a switching device with a power supply based on an experimental measurement which allows to increase the reliability of the entire mechanism operation and significantly simplify the design. Methods. In this paper, the proposed study is used and compared with experimental results at low and high frequencies. Then, a comparison is made for conducted electromagnetic interference (common-mode and differential-mode) generated by IGBT and MOSFET for different loads, and the proposed methodology is verified on an experiment suitable for predicting terminal overvoltage analysis and conducted electromagnetic interference problems. Practical value. The primary method for establishing a conducted electromagnetic interference source for switching devices is based on IGBT and a MOSFET depending on the resistive load. References 22, figures 17.

Analysis and Protection of Electromagnetic Interference in the Industrial Field

With the continuous progress of science and technology, all kinds of electrical and electronic equipment are applied to production and life. However, bad electromagnetic interference will affect the normal operation of the equipment and reduce work efficiency. This paper analyzes the situation and source of electromagnetic interference in the industrial field and introduces several common anti-interference methods. And take corresponding measures according to different types of interference. This paper introduces electromagnetic shielding, filtering, and other technologies, and the application scenarios of various anti-interference methods are analyzed. When the working environment and the nature of interference emission change, the anti-interference strategy should be adjusted accordingly. Implementing these measures will significantly improve the electromagnetic compatibility of the system, reduce the electromagnetic interference phenomenon in the industrial site, and ensure the stable and efficient work of the system. Although electromagnetic interference cannot be eliminated, summarizing and analyzing existing technologies helps to develop new technologies and provides more possibilities for anti-interference.

Advanced Characterization of a Hybrid Shielding Solution for Reducing Electromagnetic Interferences at Board Level

The development of new advanced functionalities, miniaturization, and the aim of obtaining optimized performance in electronic devices significantly impacts their electromagnetic compatibility (EMC). As electronic components become more densely packed on a printed circuit board (PCB), unintended coupling between components can cause electromagnetic interference (EMI). These requirements result in design restrictions that make using a board level shield (BLS) essential in reducing intra-system EMI in PCB designs. This contribution focuses on studying and characterizing a BLS solution based on combining a noise suppression sheet (NSS) with an aluminum layer to reduce intra-system EMI coupling. This hybrid solution has the advantage of providing a shielding option that does not require any electronic redesign. It does not need a footprint or a ground connection as it can be affixed over the EMI source. The solution is expected to provide higher attenuation levels than using only an NSS by combining the absorbing properties of the magnetic material and the loss mechanism of the metal. In order to verify the effectiveness of the hybrid BLS proposed solution, the magnetic near-field emissions of an EMI source are analyzed in this study. The experimental measurements and simulated results demonstrate a significant increase (51.6 dB at 1 GHz) in the shielding effectiveness (SE) provided by the proposed solution compared to a conventional NSS.

A Separation Method for Electromagnetic Radiation Sources of the Same Frequency

To separate electromagnetic interference sources with an unknown source number, a new separation method is proposed, which includes five key steps: spatial spectrum estimation, source number and direction-of-arrival estimation, mixed matrix estimation, separation matrix estimation, and source signal recovery. A pseudospatial spectrum estimation network based on a convolutional neural network is proposed to estimate the number of electromagnetic radiation sources, their direction of arrival, and the mixing matrix. A new loss function is designed as an optimization criterion for estimating the separation matrix. To ensure generalization, both simulated and measured datasets are used to train the proposed network. Experimental results demonstrate that the proposed separation method outperforms existing source separation techniques in terms of correlation coefficient, root mean square error, and running time. Importantly, it exhibits strong performance in underdetermined cases, as well as in overdetermined or determined cases.

Recent Progress in Poly (3,4‐Ethylene Dioxythiophene): Polystyrene Sulfonate Based Composite Materials for Electromagnetic Interference Shielding

AbstractRecent technological developments have made the emission of electromagnetic (EM) radiation a significant source of electromagnetic interference (EMI). These EMIs consist of stray EM radiations that damage and malfunction electronics and telecommunication systems. Scientists have made countless efforts to solve these problems. The demand for EMI shielding materials is fast growing due to the increasing complexity of the EM environment and EMI. Poly(3,4‐ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) is an intrinsically conductive polymer that has attracted attention due to its high electrical conductivity, processability, and environmental stability. The use of PEDOT:PSS as a shielding material for EMI is a promising alternative to traditional metal‐based materials. This review provides an overview of different strategies explored for the preparation of PEDOT: PSS‐based composites for EMI shielding and the use of carbonic fillers, metal and metal nanoparticles, magnetic particles, and MXenes in these composites. The advantages and disadvantages of different approaches are discussed, and future perspectives for the development of PEDOT:PSS composites for EMI shielding are presented. The paper concludes that PEDOT‐PSS‐based composites offer significant potential for the development of lightweight, thin, flexible, and cost‐effective green EMI shielding materials, and continued research in this field can lead to their widespread commercialization and adoption.

Identification of Unknown Electromagnetic Interference Sources Based on Siamese-CNN

Identification of Unknown Electromagnetic Interference Sources Based on Siamese-CNN

Electromagnetic interference from automobile passive keyless entry in cardiovascular implantable electronic devices

ABSTRACT Introduction The automobile passive keyless entry (PKE) system is a potential source of electromagnetic interference (EMI). We aim to determine the incidence and significance of EMI from automobile PKE system in cardiovascular implantable electronic device (CIED) patients. Methods This was a single-center cross-sectional study conducted at Maharaj Nakorn Chiang Mai hospital, Thailand. Patients with CIED were instructed to lock and unlock two automobiles using the PKE system. Any EMI or arrhythmias were detected by CIED interrogation and single-lead electrocardiogram event recorder. We also used a spectrum analyzer to identify the automobiles working frequency bandwidth. Results There was a total of 102 CIED patients. Device types included 48.0% defibrillators, 37.3% permanent pacemakers, and 14.7% cardiac resynchronization therapy device. Both interrogated data from device and event monitor revealed no incidence of EMI during the PKE activation. We failed to identify the working frequency bandwidth of the two studied cars due to very low signal strength, thus blended in with the background noise. Conclusions Automobile PKE systems transmitted very low power signals. Therefore, under normal circumstances, CIED patients can use automobile PKE system safely without any EMI regardless of key fob positions in relation to the CIED pulse generator. Trial Registration The study was registered at ClinicalTrials.gov (https://clinicaltrials.gov), and the identification number is NCT03016390.

Localization and Identification of EMI Sources in Shielding Enclosures Based on a Two-Step Source Reconstruction Method

Localization and identification of unknown electromagnetic interference (EMI) sources in shielding enclosures is a great challenge due to the complex electromagnetic environment. In this work, a two-step source reconstruction method is proposed to address this issue. The actual EMI sources are initially modeled by equally distributed equivalent electric dipoles in the shielding enclosure. Effects of surrounding environments are rigorously incorporated using the numerical Green's function which bridges between the equivalent dipoles and planar scanned tangential magnetic near-field. Next, the initial equivalent sources are downsized via evaluating the contribution of each equivalent dipole. The parameters of remaining equivalent dipoles are updated by another source reconstruction process, in which additional equivalent magnetic dipoles are added to improve precision of the equivalent model. The locations and geometries of EMI sources in the shielding enclosure can be identified clearly in terms of the updated equivalent dipoles. Furthermore, the radiated emissions from individual EMI sources can be estimated accurately. The effectiveness of this approach is validated by representative numerical examples.

Analysis of the Very Fast Transient Overvoltage in a Nuclear Plant 500kV GIL-GIS System

The simulation models of the 500kV gas-insulated transmission lines (GIL) and gas-insulated substation (GIS) systems in a realistic nuclear plant are presented in the paper. The Very Fast Transient Overvoltage (VFTO) which is generated during switching operations, is analyzed. Some affecting factors on the level of the VFTO are investigated. These factors are the location of the power source, the entrance capacitance of the potential transformer (PT), and the capacitive voltage transformer (CVT). At last, some suggestions on overvoltage calculations or calculations of electromagnetic interference sources are proposed. The conclusions can be used in insulation designing and analyzing the electromagnetic interference on the secondary system in nuclear plants and substations.

Risk of occurrence of electromagnetic interference from the application of transcutaneous electrical nerve stimulation on the sensing function of implantable defibrillators.

Transcutaneous electrical nerve stimulation (TENS) is an established method for pain relief. But electrical TENS currents are also a source of electromagnetic interference (EMI). Thus, TENS is considered to be contraindicated in implantable cardioverter-defibrillator (ICD) patients. However, data might be outdated due to considerable advances in ICD and cardiac resynchronization therapy (CRT) filtering and noise protection algorithm technologies. The aim of this pilot safety study was to re-evaluate the safety of TENS in patients with modern ICDs. One hundred and seven patients equipped with 55 different models of ICD/CRT with defibrillators from 4 manufacturers underwent a standardized test protocol including TENS at the cervical spine and the thorax, at 2 stimulation modes-high-frequency TENS (80 Hz) and burst-mode TENS (2 Hz). Potential interference monitoring included continuous documentation of ECG Lead II, intracardiac electrograms and the marker channel. Electromagnetic interference was detected in 17 of 107 patients (15.9%). Most frequent were: interpretations as a premature ventricular beats (VS/S) in 15 patients (14%), noise reversion in 5 (4.6%) which resulted in temporary asynchronous pacing in 3 (2.8%), interpretation as ventricular tachycardia/ventricular fibrillation in 2 (1.9%), and premature atrial beat in 2 (1.9%) patients. Electromagnetic interference occurrence was influenced by position (chest, P < 0.01), higher current intensity (P < 0.01), and manufacturer (P = 0.012). Overall, only intermittent and minor EMI were detected. Prior to the use of TENS in patients with ICDs, they should undergo testing under the supervision of a cardiac device specialist.

Bias-free very low frequency magnetoelectric antenna

A rapid surge in the research on very low frequency (VLF) antennas is occurring due to the demand for radio navigation and special environment communications such as underwater and underground applications. Among them, magnetoelectric (ME) antennas have recently proven to be a prospective solution for miniaturization of VLF communication systems. However, the essential magnetic bias fields (Hdc) lead to challenges of miniaturization, electromagnetic interference, and noise sources for ME antenna application. Here, a bias-free VLF ME antenna based on the magneto-gradient ME composite (i.e., annealed Metglas/Metglas/PZT/Metglas/annealed Metglas) has been designed. Owing to the interaction effect between multi-unannealed/annealed Metglas, the magneto-gradient ME composite exhibits a large direct and converse ME response (αDME = 107 V/cm Oe and αCME = 9 Gs/V at resonance) at bias-free, which is about 63% and 33% of the maximum value under optimal magnetic bias for unannealed ME composites. Moreover, a digital amplitude shift keying (ASK) modulation method is proved suitable for the as-made bias-free VLF ME antenna. Such a bias-free ME antenna provides a practicable strategy for miniaturization of VLF communication.

Results of Research into Energy Parameters and Characteristics of LED Lamps

Light emitting diode (LED) based solutions for lighting systems, particularly LED lamps, are becoming increasingly more popular due to their high reliability, energy efficiency, long lifetime, and decreasing cost. At the same time, modern semiconductor lighting equipment can be both a source of electromagnetic interference and sensitive to it. Manufacturers of LED lamps provide a few energy parameters and characteristics that make it possible to assess the interaction between the lamp and the electrical network at the design stage, but in some cases, the range of indicators provided does not fully justify the selection of LED-based solutions. The issues of electromagnetic compatibility of LED lamps are considered in the paper. LED lamps, as non-linear elements, are shown to create electromagnetic interference for the electrical network. First, emitting current harmonics, they are consumers of reactive power. The paper considers Russian and foreign documents that regulate energy parameters and characteristics of LED lamps. It is shown that datasheets of LED lamps do not fully represent their energy parameters and characteristics. The paper presents the approaches and methods based on experimental and analytical research for evaluating a wide range of energy parameters and characteristics of LED lamps. Particular attention is paid to the issue of light flicker: the range of luminous flux frequencies that negatively affect human health is shown, approaches to flicker assessment are given. Based on the study of a few LED lamps, a wide spread of their energy parameters and characteristics, the power factor and the flicker in particular, has been registered. The paper gives recommendations on the choice of products in the design of lighting systems based on LED lamps.

Advances in Modeling and Suppression Methods of EMI in Power Electronic Converters of Third-Generation Semiconductor Devices

With the development of high-frequency, miniaturized, and lightweight power electronic devices, third-generation semiconductor devices are more and more used in the main circuits of power electronic converters. The electromagnetic interference (EMI) generated by their fast switching can affect the performance of power electronic converters. Therefore, it is necessary to investigate the modeling and suppression methods of conducted noise in power electronic converters of third-generation semiconductor devices. This paper describes the EMI sources and coupling paths of EMI in third-generation semiconductor devices used in power electronic converters. The modeling methods of EMI are summarized from the perspectives of power devices and coupling paths. The suppression methods of conducted noise are summarized by suppressing EMI sources and improving coupling path characteristics. This paper provides a reference for the electromagnetic compatibility design of power electronic converters for third-generation semiconductor devices.