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The power line tower lightning surge impedance is computed using an electromagnetic field approach. After comparing the results computed by our method and those tested with both a vertical conductor and reduced scale 4-poles model of tower, the method we used is proved to be right and more practical as the soil and the grounding system of the tower can be considered in the method. Using this method,...
Standardization in the field of EMI is a complicated process which requires contributions from many experts in order to define instrumentation, test methods and emission limits. Especially for basic standards, research is needed in many areas, e.g. contributions of basic principles of metrology and electromagnetic field theory (wave propagation, antennas and test site configurations) as well as contributions...
The paper aims to present the Romanian concerns in electromagnetic compatibility (EMC) field - European legislation transcription, testing and calibration laboratories, non-governmental organizations, scientific events and international cooperations
We have proposed the transmission line (TL) model of lightning return strokes generalized to include a tall grounded strike object and an electrically long upward connecting leader. This model incorporates a lumped series voltage source at the junction between the descending leader and an upward connecting leader launched from the top of the strike object. We have derived expressions for current along...
A quantitative analysis of parasitic coupling between elements of a 12 V DC motor and its damping chokes is presented. This analysis deals both with inductive couplings between several chokes as well as armature windings, and with capacitive couplings between chokes and the motor casing. It produces a motor model to take these effects into account. It is shown that while both types of coupling depend...
The paper describes a future trend of EMC simulation on PCB level. The coupling of multiconductor multilayered transmission lines in modern automotive control units is calculated in realtime during the layout process. Serving as an example a triplate structure with parallel planar microstrip lines is investigated. A forward function is developed to calculate the coupling factor between the microstrip...
This paper investigates the frequency-selective scattering properties of a general bi-isotropic cylindrical shell with an interior metal coating. Either a nonreciprocally Tellegen medium or a reciprocally chiral one is considered as the general bi-isotropic cylindrical shell. To address this scattering problem, a state-equation based theoretical model is developed. A finite-difference algorithm is...
Quiet zone is a region in the anechoic chamber where the reflexivity is controlled at a designed level. Analytical formulation and hybrid methods are implemented to analyze the quiet zone in an anechoic chamber, since it is difficult to simulate the whole chamber with periodic absorber arrays. Herein the reflection from a single absorber is operated with FEM while the reflection from absorbing walls...
In this paper a novel stable time-domain approach is presented to compute the scattering from arbitrarily shaped 3D dielectric objects. The method applies both electric and magnetic field boundary conditions on the surfaces of homogeneous structures while considering the electric currents as unknowns. For triangular patches, modeling the surface of the composite body, RWG basis functions are utilized...
In this paper a novel method for harmonic influence assessment for large power systems is presented. The approach is based on the calculation of the harmonic flow in the power network. In this process the Jacobian matrices for each frequency are computed. These matrices make it possible to investigate the sensitivity of the network with respect to the harmonic order being analyzed. To find a solution...
Recent advancements in the field of communications technology include the use of high speed data transmissions with extremely wide frequency bandwidth. This technology is widely employed in ultra-wideband (UWB) communication systems which can produce significant EM emissions at microwave frequencies. A key element in assessing the vulnerability of equipment to UWB signals involves an understanding...
In substations, shielded cables are widely used to reduce transient electromagnetic interference to the relay and control equipments due to the switch operation. Both the transfer impedance and transfer admittance are quantities for expressing numerically the mechanism that allows the passage of electromagnetic energy across the cable shield. Theoretical models to compute both the quantities often...
This paper presents the effect of conducted electromagnetic interference emission and harmonics distortion generated from a single phase small grid connected inverter to power system. Controlling technique is sinusoidal pulsewidth modulation (SPWM) for a bipolar voltage switching inverter. Modulation index, switching frequency and power flow are key parameters to control the conducted electromagnetic...
The transient near-field of the electrostatic discharge (ESD) is a kind of high power transient phenomenon, which strongly affects the operation of the electronic devices. In this paper, the transient field of the indirect electrostatic discharge through the vertical coupling plane (VCP) is numerically simulated by using the FDTD method with the PML. The configuration of the current source is considered...
An EMTP model is presented for calculating overvoltage in transformer windings under VFTO in this paper. Firstly, the voltage transfer functions are calculated from the S parameters which are measured by network analyzer or calculated from the distributed parameters of transformer windings. Secondly, the voltage transfer functions are fitted with rational functions by vector fitting codes and then...
The conversion between the common and the differential modes is of great importance in the transmission of data over poorly balanced cables such as electrical wiring. In this paper, we have studied some of the mechanisms involved in this conversion, both experimentally and theoretically. The results show that along-the-line variations in the line parameters be it gradual or abrupt, are responsible...
We measured leaked electromagnetic radiation that came from a laser printer. Using the measured data, we were able to easily reconstruct the printed image. To avoid unwanted monitoring, we have to prevent the printed image data from being reconstructed. In this paper, we first measured the magnetic field at a near field point and then reconstructed the image. Then, using the Sommerfeld integration...
A plot of land was allocated for the building of recreational facilities. However, the site is located next to a HF transmission station, thus raising concerns of radiation hazards to personnel at the site. Initial electric field measurements concluded that some parts of the land experienced electric field levels that exceeded the maximum safety exposure level (28V/m) recommended by the ICNIRP standard...
The ever growing increase in speed of digital signals has made more difficult the achievement of conformity about limits emissions. It often happens that to verify the requirements of standards on these emissions the use of a metallic enclosure is necessary: in this way the power radiated by the system is reduced. The effect on radiated emission due to the presence of a slot on the frontal part of...
In this paper, design for EMC of LCD driver IC is proposed. By the analysis with package parasitic parameters and EMC test pattern, local power/ground noise in LCD driver IC simulated. As a result of analysis, design for lower peak of EMI spectrum and design for lower mean level of that is proposed at the same time. In addition, decoupling cap with CMOS process can decrease EMI spectrum without any...
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