This paper develops a basic idea which allows low frequency electromagnetic fields generated by cylindrical conductors, with very small radii compared their length, to be calculated. The proposed method can applied both power overhead conductors and those buried in conducting environment. presents direct application for this concept consists calculating the created substation grounding system following an accidental short circuit or lightning stroke. finite element (FEM) several formulations...

Following up previous research concerning low frequency electromagnetic emission from a grounding system [Nekhoul et al., 1995], the authors suggest methodology which allows complete study by finite element method (FEM) of in significant frequential spectrum stroke lightning or short circuit (f/spl les/1 MHz). In this as well calculating field at any point space (ground and air), we pay particular attention to variation with impedance system. Suggested modelling takes into account eddy...

Randomized pulse width modulation (RPWM) deals better than deterministic PWM (DPWM) with electro-magnetic compatibility (EMC) standards for conducted electromagnetic interferences (EMI). In this paper, we propose a dual RPWM scheme full bridge DC-DC voltage converter. This is based on triangular carrier two randomized parameters. By using directly the parameters of carrier, mathematical model power spectral density (PSD) output developed. Then, PSD analysis shows EMC advantage proposed...

Randomised pulse width modulation (RPWM) technique has become a viable alternative to deterministic (DPWM). By spreading the power spectrum in continuous noise, this new better complies with electromagnetic compatibility (EMC) requirements for conducted interferences (EMI) and allows reducing emitted acoustic noise variable speed drives (VSDs). The most popular RPWM schemes are randomised position (RPPM) carrier frequency (RCFM). combination (RCFM-RPPM) or dual (DRPWM) also been proposed. In...

The present work deals with modeling of the transient behavior grounding systems in presence layered media. A simple and efficient Transmission Line (TL) model featuring use Finite Difference Time Domain (FDTD) is proposed. proposed approach easily accounts for influence semi-infinite media (soil or air) imposes conditions at interfaces. TL verified through direct solution Maxwell's equations time domain by means FDTD method. Some illustrative computational examples addressing some...

In order to comply with Electro-Magnetic compatibility (EMC) standards for conducted Interferences (EMI) at low frequencies and reduce audible noise annoyances in electric machines, we propose an Optimal Random Pulse Width Modulation (ORPWM) the control of three-phase inverter a Variable Speed Drive (VSD). After giving modulating principle, spectral analysis output voltage shows EMC advantage proposed ORPWM compared classical Deterministic PWM (DPWM). An application VSD using induction motor...

This paper presents a novel multi-spectral palmprint recognition approach based on multi-resolution 2D log-Gabor filtering aiming to enhance the performances of coding-based approaches using images. The proposed consists following three major steps: (i) feature extraction step employs filter bank where final map is composed bitwise competitive coding, (ii) matching uses normalized Hamming distance capture efficiently similarities between maps, and (iii) in decision step, maps are fused get...

In this work the transient analysis of a power network excited by indirect lightning is performed directly in time domain. Using FDTD, we calculate induced currents and voltages each node for three-phase network. The topological where element (power line lumped charge) considered, allows deducing matrix equation. electrical matrix, lines are represented equations, junctions extremities nodes Kirchhoff laws. electromagnetic field emitted second member frequency dependence parameters istaken...

Abstract The objective of this work is to provide a simplified model analyse the electromagnetic emission grounding grid thus enabling engineers perform parametric studies rapidly without greater loss accuracy. proposed approach based on use transmission line theory and concept dipole radiation in presence lossy half‐space including Sommerfeld integral approach. proposes determine fields (soil air) current distribution system. described illustrated with applications. limitations advantages...

The modern power electric network is subject to insure more and complicated functions; the main functions are transfer of energy information. faults in wiring cables constitute one worst problems network. In practice, combination Time Domain Reflectometry (TDR) wavelet transform generally used detect localize Classically, identification process based on decomposition fault signal details approximations using Discrete Wavelet Transform (DWT) build some errors both at position nature. For...

The paper presents an assessment of human exposure to extremely-low-frequency (ELF) electric fleld generated by a power line using the rotationally-cylindrical body model. formulation is based on Laplace type continuity equation. induced current density in three-dimensional (3D) model obtained solving equation via Finite element method (FEM). main objective highlight some parameters in∞uencing distribution density, such as ohmic contact between feet and soil due soles shoes, electrical soil....

The main purpose of this work is to implement a new and accurate approach based on Time Domain Reflectometry (TDR) combined with Adaptive Neuro-Fuzzy Inference System (ANFIS) solve the problem soft faults detection localization complex wiring electric network. Firstly, response transmission line given by applying Finite Difference method (FDTD) equations. Then, ANFIS used inverse which permits detect localize fault. Finally, very acceptable results are obtained many problems solved at same...