Electromagnetic Pulse Coupling Research Articles

Analysis on the low-frequency electromagnetic pulse coupling to horizontal electrically short lines

In this study, we investigated the coupling features of the nuclear electromagnetic pulse (NEMP) on overhead cables in the middle-and-far regions, different from the transmission line model commonly used for field-line coupling in high-frequency cases, using a simpler lumped approximation to solve the electrically small size model in low-frequency cases. To verify its effectiveness, a simulation model with the same conditions was set up using the software of Computer Simulation Technology (CST), and cable coupling experiments were performed in a laboratory environment using a bounded-wave electromagnetic pulse simulator. The calculated results of the lumped approximation circuit were compared with the CST simulation and measured results, and the agreement was good. The results also shows that the load exhibits a differential response in the case of the low impedance and it is consistent with the excitation signal in the case of the high impedance. Finally, some more experiments were constructed to analyzed the effect of different cable parameters on the cable load response through experiments, and the experimental results are also in general agreement with the theoretical analysis, in which the induced signal of the low-impedance load is mainly determined by the magnetic field in the direction normal to the cable and the ground loop and the induced signal of the high-impedance load is mainly determined by the electric field in the direction of the height of the cable erection.

Simulation analysis of electromagnetic pulse susceptibility and hardening design for system-in-package SZ0501

The electromagnetic pulse (EMP) susceptibility of System-in-Package (SiP) SZ0501 was investigated by field-circuit combination simulation method in this paper. The electromagnetic pulse coupling model of the SiP is established by an electromagnetic field simulation software (CST). Considering different incident and electric field direction, the type and distribution of pins, the coupled voltages via pins of the SiP under EMP were obtained to analyze the electromagnetic susceptibility of the SiP. Simulation results indicate five major factors affecting the electromagnetic susceptibility of the SiP: the effective electric field integration on the pins, the distribution of pins, the terminal cases of pins, the shunt effect of the output ports of the power plane, and the kind of ground planes. And compared with side incidence, SiP is more sensitive to EMP from above. Finally, some factors affecting the shielding effect are considered, a shielding box is designed and then verified to reduce the electromagnetic susceptibility.

Joint Analysis of Front-Door and Back-Door Couplings of PIN Limiter Based on Improved Equivalent Circuit Model

Based on the previous research on electromagnetic pulse coupling, which pays more attention to the front-door coupling or the back-door coupling alone, this paper analyzes the influence of an electromagnetic pulse on electronic devices and systems through the joint analysis of front-door and back-door couplings using the finite-difference time-domain method (FDTD). This specific measure is used to simplify the front-door coupling to the voltage source injection, which occurs simultaneously with plane wave irradiation. This coupling scheme of the front door and back door with the voltage source and plane wave acting simultaneously is rarely seen in previous analyses, which also gives consideration to the working state of the circuit. Although the equivalent circuit model is widely used, it cannot effectively reflect the working state of the diode circuit under the conditions of large injection and high frequency. In view of the limited application scenarios of the traditional equivalent circuit model, which cannot accurately describe the internal response characteristics of the diode under different electromagnetic pulse coupling, this paper introduces an improved equivalent circuit model based on the physical model. Taking the Positive Intrinsic-Negative (PIN) limiter as the target, this paper analyzes the influence of the front-door and back-door joint coupling on its performance under different electromagnetic pulses and then gives protection suggestions.

Prediction method of Ultra-wideband electromagnetic pulse coupling in slotted cavity

With the develofpment of UWB electromagnetic pulse radiation systems, people are paying more and more attention to its serious threat to electronic equipment. The effect of UWB electromagnetic pulse has also become an important content in the field of electromagnetic compatibility. In an UWB radiation system, the distance between the device under test and the transmitting antenna is different, and the radiation field received is also different. Therefore, in actual tests, the test body is often placed at different distances from the antenna to perform multiple measurements to obtain test data as required. Based on this, this article takes the cavity as an example, and proposes a method of using the system transfer function to predict the response of the impulse field inside the cavity to simplify the test and quickly obtain the test data. Firstly, the impulse field response of a certain point with and without a cavity is measured respectively, and then the time domain response is inversely Fourier transformed to obtain the frequency domain transfer function of the test body. Finally, using the transfer function to convolute with the field to be measured, the response of the impulse field inside the cavity can be predicted under the condition of the field to be measured. It is verified by experiments that this method can better predict the response of the impulse field inside the cavity under different distance conditions, and has the characteristics of simple calculation and good prediction effect. At the same time, the transfer function obtained by this method can be used to predict the arbitrary impulse field response of the cavity in its frequency range.

Research on the Coupling Characteristics of Electromagnetic Pulse of Electronic Equipment

The problem of electromagnetic interference is becoming more and more prominent in complex environment, and the study of coupling effect between electronic devices is very important to guide the design of electromagnetic protection. In this paper, CST electromagnetic simulation software is used to study the strong electromagnetic pulse coupling effect of the device chassis and harmonious vibration cavity, to simulate the coupling characteristics of the cavity by square hole seam area and the length of the outer cable in the cavity, and then to study the coupling characteristics of the two coupling methods at the same time through simulation and analysis of the coupling electric field and electromagnetic pulse simulation test. The results show that the larger the hole area, the stronger the field strength of coupling into the cavity, and no effect on the resonant point position in the cavity; The longer the cable, the stronger the field force coupled in the center of the cavity, the resonant frequency in the cavity is basically unchanged; When the two coupling methods exist at the same time, the size of the hole seam is small compared to the wavelength, which makes it difficult for electromagnetic waves to enter the inside of the cavity, mainly as cable coupling, and the other is mainly in the form of hole coupling.

Experimental analysis of electromagnetic pulse effects on engine fuel electronic control system

In this paper, the fuel electronic control system of the engine as an engine control process is designed and constructed to provide the fuel adjustment function of the aero-engine. Then, the electromagnetic pulse (EMP) experiment is established by exposing it to electromagnetic field pulses of the bounded-wave simulator. Now, the damage threshold is also determined. At the same time, the induced differential voltage and common current signals are measured through the printed circuit board (PCB) port, which is necessary to cause a specific microprocessor to fail. The wavelet transform is employed to establish a time-frequency method to process the induced voltage signal. The susceptible frequency areas and coupling energy distribution are applied to the speed acquisition system. Their characteristics are employed to propose a new electromagnetic interference decrease method in both time and frequency domain. This method could be considered as a useful tool for studying the electromagnetic pulse coupling interference.

Design, Modeling & Simulation of Analysis of coupling to Cables due to Electromagnetic Pulse (EMP)

This paper is to analyze the EMP coupling to cables using 3D EM Modeling and Simulation Analysis. Bounded wave transmission line structure as per MIL-STD 461, RS105 EMP requirement in terms of peak electric field of 50KV/m with rise time-2.3ns and pulse width-25ns was developed. Single conductor cable, RF Coaxial cable were modeled. EMP Coupling to cables was carried out by placing the cable under generated EMP field in terms of induced voltage and currents due to EMP fields. EMP coupling to active line with matched termination also analyzed.

Design, Modelling & Simulation Analysis of Electromagnetic Pulse (EMP) Coupling to Microstrip

Design, Modelling & Simulation Analysis of Electromagnetic Pulse (EMP) Coupling to Microstrip

The electromagnetic effect study of GIS enclosure under high‐frequency electromagnetic pulse

In gas insulated switchgear (GIS) substation, due to the operation of disconnect switch and circuit breaker, as well as short-circuit fault, SF6 will break down very rapidly. The superposition of refraction and reflection of high-frequency travelling waves will cause the very fast transient electromagnetic pulse (EMP). High-frequency EMP propagating along GIS core wire will couple to GIS enclosure which forms transient enclosure voltage (TEV). Through the study of new GIS enclosure coupling model which can be verified by site test and frequency effect on the enclosure coupling under high-frequency EMP, results indicate the generation of TEV is closely related to GIS structures and the electromagnetic wave propagation characteristics on its core wire and enclosure. Electromagnetic coupling model must consider the entire propagating and coupling process of EMP in GIS. Paper also shows that TEV is mainly formed by high frequency >0.1 MHz EMP coupling and the difference on coupling extent when frequency is >1 MHz is small.

Discharge current distribution in stratified soil under impulse discharge

The mobility of charge particles traversing a material defines its electrical properties. Soil (earth) have long been the universal grounding before and after the inception of active ground systems for electrical appliance purpose due to it semi-conductive properties. The soil can thus be modelled as a single material exhibiting semi-complex inductive-reactive impedance. Under impulse discharge such as lightning strikes to soil this property of soil could result in electric potential level fluctuation ranging from ground potential rise/fall to electromagnetic pulse coupling that could ultimately fail connected electrical appliance. In this work we have experimentally model the soil and lightning discharge using point to plane electrode setup to observe the current distribution characteristics at different soil conductivity [mS/m] range. The result presented from this research indicate above 5% shift in conductivity before and after discharge which is significant for consideration when dealing with grounding designs. The current distribution in soil have also be successfully observed and analysed from experimental result using mean current magnitude in relation to electrode distance and location, current density variation with depth all showing strong correlation with theoretical assumptions of a semi-complex impedance material.

The Lightning Electromagnetic Pulse Coupling Effect Inside the Shielding Enclosure With Penetrating Wire

AbstractTo study the lightning electromagnetic pulse (LEMP) coupling and protection problems of shielding enclosure with penetrating wire, we adopt the model with proper size which is close to the practical engineering and the two-step finite-difference time-domain (FDTD) method is used for calculation in this paper. It is shown that the coupling voltage on the circuit lead inside the enclosure increases about 34 dB, when add 1.0 m long penetrating wire at the aperture, comparing with the case without penetrating wire. Meanwhile, the waveform, has the same wave outline as the lightning current source, shows that the penetrating wire brings a large number of low frequency component into the enclosure. The coupling effect in the enclosure will reduce greatly when penetrating wire has electrical connection with the enclosure at the aperture and the coupling voltage increase only about 12 dB than the case without penetrating wire. Moreover, the results show that though the waveguide pipe can reduce the coupling effect brought by the penetrating wire, the exposing part of penetrating wire can increase the coupling when the penetrating wire outside the enclosure is longer than the waveguide pipe and the longer the exposing part is, the stronger the coupling is.

Electromagnetic Pulse Coupling Analysis of Electronic Equipment

High-intensity nuclear explosion caused by high-altitude nuclear electromagnetic pulse through the antenna, metal cables, holes and other channels, coupled with very high energy into the electronic device, and cause serious threats. In this paper, the mechanism, waveform, coupling path and damage effect of nuclear electromagnetic pulse is analyzed, and the coupling mechanism of nuclear electromagnetic pulse is studied.

JOR Iterative Method for the Modeling of MTLs Excited by EMP

In recent years, the distributed analytical representation and iterative technique (DARIT) based on the Jacobi iteration method (Jacobi-DARIT-field) and the Gauss-Seidel iteration method (Seidel-DARIT-field) were proposed to handle the transient electromagnetic field or the electromagnetic pulse (EMP) radiated field coupling to multiconductor transmission lines (MTLs). Compared to the Seidel-DARIT-field method, the Jacobi-DARIT-field method has a higher computational efficiency but a lower convergence rate. In order to improve its convergence rate, this letter extended the Jacobi-DARIT-field method with the Jacobi over relaxation (JOR) iteration algorithm and proposed a JOR-DARIT-field method. The performances of the JOR-DARIT-field method and the Jacobi-DARIT-field method were compared through the MTL modeling examples. It could be concluded that both methods have a high computational efficiency when computing the EMP coupling to MTLs. However, the JOR-DARIT-field method has a higher convergence rate than the Jacobi-DARIT-field method with a proper relaxation factor (RF).

Simple transmission line model suitable for the electromagnetic pulse coupling analysis of twisted-wire pairs above ground

Simple transmission line model suitable for the electromagnetic pulse coupling analysis of twisted-wire pairs above ground

电磁脉冲耦合效应的等效源建模及应用

电磁脉冲耦合效应的等效源建模及应用

Characteristics of Electromagnetic Pulse Coupling into Annular Apertures

Electromagnetic pulse (EMP) coupling into the annular apertures can disturb or damage much electronic equipment. To enhance electronic system’s capability of anti-electromagnetic interference, the finite difference time domain method (FDTD) was employed to study the characteristics of electromagnetic pulse coupling into the cavity enclosures with annular apertures. The coupling characteristics of annular apertures with different shapes (rectangle, square and circle) were discussed. It shows that, in the case of the same aperture area, the coupling energy of electromagnetic pulse into the circular annular aperture is smaller than that into the rectangular and the square ones. To the rectangular annular aperture, while the polarization direction of the incident electromagnetic pulse is perpendicular to the long side of the rectangular annular aperture, the coupling energy is larger when the aspect ratio of the rectangular annular aperture is larger. The coupling effect of incident pulse with short pulse width is obviously better than the one with longer pulse width. The resonance phenomenon of the coupled waveform occurs in the cavity. DOI: http://dx.doi.org/10.11591/telkomnika.v11i11.3544

Analytic Iterative Solution of Electromagnetic Pulse Coupling to Multiconductor Transmission Lines

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.

Simulation of Transient EMP Effects Coupling through Apertures Using Sub-Gridding FDTD Algorithm

Transient electromagnetic pulse (EMP) can easily couple into the inner of targets via apertures. To calculate the EMP coupling effects on a cylinder object with openings, the coupling course is simulated using sub-gridding FDTD algorithm in this paper. Gauss pulse and double exponential pulse are selected as the incident pulse source. The coupling EM field strength E inside the object and the current density J on the surface are calculated. Several rules about EMP coupling effects are gotten both in time and frequency domain. The results can help us to understand the damage effects of transient EMP.

Numerical Study of Lightning-Induced Currents on Buried Cables and Shield Wire Protection Method

In this paper, the two-step finite-difference time-domain method of solving full-wave Maxwell's equations is adopted to analyze the lightning electromagnetic pulse (LEMP) coupling to buried cables. The influences of lightning strike point, cable length, and ground conductivity on the LEMP coupling to buried cable are evaluated. The method of using shield wires to decrease the lightning-induced currents on the buried cables is proposed, and the protection efficiencies of different installing ways of the shield wires are evaluated. The numerical results show that when the lightning strike point is in the axial direction of the cable, the coupling is rather strong; the induced current acutely increases as the lightning strike point approaches the cable; when the length of the cable does not exceed about 150 m, the induced currents at the cable ends increase as the length increases, whereas once the length of the cable exceeds 150 m, the induced currents begin to decrease; the shield wires can effectively decrease the lightning-induced currents on the buried cables, closer the shield wire, greater the protection efficiency, and more shield wires provide greater protection efficiency.

Electromagnetic Pulse Coupling inside a Rectangular Enclosure with an Aperture

The transmission line matrix time domain (TLM-TD) method is used to simulate the electromagnetic pulse (EMP) cou-pled inside a shielding box with an aperture. Simulations for different electromagnetic pulses regarding to different rise time and fall time have been performed. The results for shielding effectiveness of these different excitations have been presented. A simple method that uses an extra metal for reducing the interference has also been proposed and tested.