Transient Magnetic Field of Energized Buried Grid

A new approach is adopted in this paper for modeling the transient magnetic field, radiated by buried grid under lightning strokes. This approach summarizes each of three methods: analytical formula, based on electrical dipole theory for determining radiated magnetic field in infinite conductive medium, modified images theory for taking into account the interface in the half space, and transmission line approach for determining the longitudinal and leakage currents. The model can be used to predict the transient characteristic of grounding systems because, it can calculate magnetic field in any points of interest, it is sufficiently accurate, time efficient, and easy to apply

Tranzijentni odziv uzemljivačkog sustava u dvoslojnom tlu primjenom teorije prijenosnih linija

The present work deals with modeling of the transient behavior of grounding systems in the presence of layered media. A simple and efficient Transmission Line (TL) model featuring the use of the Finite Difference Time Domain (FDTD) is proposed. The proposed approach easily accounts for the influence of semi-infinite media (soil or air) and imposes conditions at the interfaces. The TL model is verified through the direct solution of the Maxwell\u27s equations in the time domain by means of the FDTD method. Some illustrative computational examples addressing some engineering applications stemming from industry are given in the paper.U radu se razmatra modeliranje tranzijentnog odziva uzemljivačkog sustav au prisutnosti slojevitih sredina. Predložen je jednostavan i efikasan model prijenosne linije uz upotrebu metode prijenosnih linija u vremenskom području. U okviru predloženog pristupa lako se uzima u obzir utjecaj polubeskonačnih sredina (tlo ili zrak) te postavljaju uvjeti na granici sredina. Model prijenosne linije verificira se direktnim rješenjem Maxwellovih jednadžbi u vremenskom području primjenom metode konačnog diferencija u vremenskom području. U radu se daju neki ilustrativni računalni primjeri koji se odnose na neke inženjerske primjene proizašle iz prakse

Elektormagnetska kompatibilnost kod zrakom izoliranih transformatorskih stanica

In this work, transient coupling between the bus bars of the Air Insulation Substation (AIS) and the control cable located at its proximity is analyzed. The present study accounts for the real complex geometry of the bus bars and the finite conductivity of the soil. A time domain formulation of the problem is proposed in this work. The direct time domain formulation based on the use of Transmission Line (TL) theory and the Finite Difference Time Domain (FDTD) solution method. The excitations are given in the form of the localized current or voltage generator, respectively, and related electrical field radiated by bus bars. To ensure the electromagnetic compatibility (EMC) requirements the current induced in the transmission cable is analyzed by means of the Pencil Method that will allow one to identify the dominant frequencies in the interference signal. Various illustrative examples are given in the paper.U ovom radu analizira se tranzijentna sprega između sabirnica zrakom izoliranih transformatorskih stanica i kontrolnog kabela u njenoj blizini. Ovom analizom uzima se obzir složena geometrija sabirnica i konačna vodljivost tla. Direktna vremenska formulacija zasniva se na teoriji prijenosnih linija i metodi konačnih diferencija u vremenskom području. Pobude su dane u vidu lokaliziranih strujnih, donosno naponskih generator i odgovarajućeg električnog polja kojeg zrače sabirnice. Da bi se osigurali zahtjevi elektromagnetske kompatibilnosti struja inducirana u prijenosnoj liniji analizira se primjenom Pencil Method koja omogućava identifikaciju dominantnih frekvencija u interferencijskom signalu.Razni ilustrativni primjeri se obrađuju u radu

Comparison of Matrix Pencil Extracted Features in Time Domain and in Frequency Domain for Radar Target Classification

Feature extraction is a challenging problem in radar target identification. In this paper, we propose a new approach of feature extraction by using Matrix Pencil Method in Frequency Domain (MPMFD). The proposed method takes into account not only the magnitude of the signal, but also its phase, so that all the physical characteristics of the target will be considered. With this method, the separation between the early time and the late time is not necessary. The proposed method is compared to Matrix Pencil Method in Time Domain (MPMTD). The methods are applied on UWB backscattered signal from three canonical targets (thin wire, sphere, and cylinder). MPMFD is applied on a complex field (real and imaginary parts of the signal). To the best of our knowledge, this comparison and the reconstruction of the complex electromagnetic field by MPMFD have not been done before. We show the effect of the two extraction methods on the accuracy of three different classifiers: Naïve bayes (NB), K-Nearest Neighbor (K-NN), and Support Vector Machine (SVM). The results show that the accuracy of classification is better when using extracted features by MPMFD with SVM

Combined random space vector modulation for a variable speed drive using induction motor

and analyzed in steady-state characteristics of the motor B Aimad Boudouda [email protected] Nasserdine Boudjerda [email protected] Khalil El Khamlichi Drissi [email protected] Kamal Kerroum [email protected] 1 Department of Electrical Engineering, University Mohamed Seddik Ben Yahia, Jijel, Algeria 2 Pascal Institute, Blaise Pascal University, Clermont Ferrand, France in closed loop, which is advantageous in reducing acoustic nois

Caractérisation d'une grille de mise à la terre par une équation de diffusion

Cet article a été rédigé conjointement avec l'équipe CEM de l'université de JIJEL en Algérie dans le cadre d'un contrat de recherche internationa

Advanced assessment of the risk of underestimating EMC conducted tests for satellites in-flight conditions

International audienc

Caractérisation du risque CEM de sous-évaluation des tests conduits sur satellites en configuration vol

International audienc