The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper describes the calculation of the RLCG frequency-dependent parameters with the finite element method (FEM) for the computation of the fast transient overvoltages (FTOs). The proposed calculation intends to match the simulated results with the experimental measurements. It allows identifying the location of the dissipative effects and the contribution of each parameter. Numerical results...
This paper presents computer simulations of ship's deperming. The ferromagnetic-hulled ship or submarine develops a magnetic signature due to magneto-mechanical interaction with the Earth magnetic field. There are several methods of ship's deperming [1,2]. The deperming method with system of coils lying on the seabed is presented in this paper. The deperming process was calculated in Opera 3D 18R2.
In this paper two multiphysics models are performed in order to predict vibration behavior in a five-phase flux switching machine. Radial magnetic stress is calculated using both analytical model obtained by permeance network and finite element model. In order to evaluate stator radial accelerations, each of the two magnetic models are coupled with an analytical mechanical model to diagnose faulty...
The aim of this study is to explore the possibility of using flux switching linear tubular machines in a free piston energy conversion (FPEC) system. In FPEC systems, acceleration and therefore speed are often relatively high, which impose to have a reduced number of poles, meanwhile the cogging force will be relatively high. In order to reduce the cogging force two techniques are combined. The analysis...
The paper deals with method of description of the stranded windings of the electromagnetic energy converters. The approach, based on current flow equations and the current vector potential T0 formulation, for the magnetic field sources and turns space arrangement description has been proposed. The modification of known T0 method by incorporating to model equations the additional coefficients correcting...
In this paper two electromagnetic methods, Barkhausen noise and AC magnetization process observation, were used for detailed local monitoring of the steel samples fatigue degradation. In order to evaluate stage of the damage process, a multivariate analysis of obtained signals parameters distributions and data fusion was carried out.
This article presents the numerical analysis of the magnetic field that occurs around the transformer after it has been switched off. The purpose of this analysis was to determine if it is possible to define the residual fluxes in the legs of transformer based on the measurements of this field. These studies have allowed us to determine the quantity and location of the sensors. The influence of the...
A hybrid genetic algorithm (HGA) is proposed to optimize the rotor shape of an Interior permanent magnet machine which is used in EV application. The novel method obtain lower iron loss and torque ripple as well as higher average torque and efficiency for the machine. The optimization results of the HGA design is compared with the initial and genetic algorithm designs. It is shown that the performance...
Because many electric devices using magnetic materials are developed in a modern society, it is important to evaluate its magnetization characteristics accurately. In this paper, we aim to calculate magnetic circuit method with summation of harmonics. One of the important ideas in hysteresis-based magnetic circuit calculation is based on the harmonic balance approach. A magnetization characteristic...
In this paper the optimization process of a wireless body area network is presented. The optimization goal is to improve the performance of the body area sensor network with respect to the on-body transmission channel and off-body link performance. The sensor network consists of one node with fixed position (1) towards the ear and two sensor nodes that are located on the chest (2) and the back (3),...
Rectennas operating as microwave electromagnetic energy harvesting systems has a low input power and, as a result, a very low output power is delivered to the load. In this paper, is purposed a method to increase the output power by the use of a parallel association of rectennas. The antennas simulations were carried out using Computer Simulation Technology software. Rectifier circuits were designed...
The finite difference time domain method (FDTD) is widely used in solutions of electromagnetic problems, but has as a condition of stability, the Courant-Friedrich-Levy (CFL), that limits the step time to be used. The method has a high computational processing time and memory usage in three-dimensional analysis for electromagnetic cavities due to the high number of resonance frequencies to be simulated,...
Electric traction systems are a potential source of stray currents. The important problem, technically is to evaluate the harmful effects (electrolytic corrosion) that an electrified railway has on nearby earth-return circuits (e.g. pipelines). This phenomenon is stochastic and may aggravate electrochemical corrosion in different pipeline regions depending on the position of the vehicle, the load...
This paper presents an overview of the different solutions of electrospinning systems. 3D parameterized numerical models for these systems were prepared too. The 3D models allows to analyze the distribution of the electric field. In addition, examples of calculations for the analyzed systems in the form of electric field quantities distributions are also shown. In this paper the authors used COMSOL...
A number of investigations were undertaken to enhance the behavior of high voltage outdoor insulators by adopting numerical methods of optimization, but no work is performed to account for the presence of pollution. In this paper, a shape optimization of a high voltage insulator is achieved with the objective of reducing the tangential electric field along its polluted surface by means of numerical...
The article presents an algorithm and computer software for the optimization of excitation system of permanent magnet synchronous motor. The software consists of two independent modules: a module containing mathematical model of the device and an optimization solver. The mathematical model of the motor has been elaborated in the Ansys Maxwell environment. The Bat Algorithm (BA) has been applied in...
Article presents method of storing and processing Big Data using object-oriented datatype in commercial relational database server. Methodology was presented based on genomic data. Additionally, some methods of pattern matching implemented in the object were described and commented. Due to set of numerical experiments based on real data the efficiency of the system was testified. Obtain results shows...
Visual saliency modeling is becoming important and challenging for many scientific disciplines (robotic systems, psychophysics, cognitive neuroscience and computer science). Proposed model indicates possible salient regions by taking into consideration face presence and motion which is essential in motion pictures. By combining face presence and motion we can obtain credible saliency map with low...
Two-stage SC + Finite Difference (FD) procedures have been proposed since a long time to solve electrostatic and magnetostatic field plane problems in case of inhomogeneous dielectric materials. This had allowed to overcome accuracy problems caused by convex corners in the domain boundary and relevant field singularities, and to apply FD solvers in rectangular domains. In this paper, compound procedures...
Induction machines are commonly used in traction applications due to their robustness and lower production costs when compared to the Permanent Magnet Synchronous Motor (PMSM). In such traction applications, the induction machines are mainly operated by field oriented control. This control technique requires an accurate knowledge of the machine's parameters. The accuracy of the parameters influence...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.