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This paper presents a computational tool intended to calculate and minimize the electric fields at ground level of High Surge Impedance Loading transmission lines. This type of transmission line achieves higher power transmission rates by utilizing optimized configuration for the phase conductors. This method is advantageous over other actions taken by the utility company such as increasing the maximum...
The aim of this paper is the multi-physical modeling of synchronous permanent magnet machines using reluctance network, lumped mechanical & thermal models. First, the modeling approaches are presented and validated by comparing the obtained results to those of finite element method. Second series of parametric studies are done to maximize the torque's mean value and reduce its ripple by acting...
Electrochemotherapy (ECT) is a local therapy used in clinical practice. This therapy improves the drug uptake of tumor tissue since it permeabilizes cell membranes by means of an electric field. Nevertheless, the tumor tissue could be characterized by inhomogeneity areas and needle electrodes could be implanted in tissue with different values of conductivity. The authors investigate by means of numerical...
The accurate knowledge of the machine parameters is a well-known important prerequisite for the inverter control design of variable speed drives. Due to the non-linear characteristics caused by cross-coupling and saturation effects the calculation of the inductances and in particular the magnetic flux of synchronous machines cannot be done straightforward. This paper presents a numerical stable method...
In the paper, a new approach to the robust optimal design is proposed. The idea is to consider the sensitivity as an extra objective function which is cost-effective. The optimal design of a switched-reluctance motor is considered as the case study: since the case study exhibits two design criteria, the Pareto front trading off three objective functions is approximated by means of evolutionary computing.
The feasibility of applying circular microstrip antennas for deformation measurement is studied. For this purpose the frequency dependent reflection coefficient S11 is analyzed. Deformation of the sample influences sensor geometry and causes a change of patch current distribution and resonant frequency shift. This effect is utilized to deformation evaluation. So far, microstrip sensors were utilized...
This work analyzes some possible converter switching strategies so as to achieve higher efficiency and better current waveforms in a high power and low cost three-phase and three-level active AC-DC conversion.
A switched reluctance linear tubular motor that is proposed as a simple and cheap drive for a water pumps, which are in need in developing countries, is analyzed in the paper. In order to develop a strong driving force at the reciprocating motion a double coil motor with two springs is proposed. Driving electromagnetic static forces are analyzed for various motor dimensions using FEM. Simulation results...
This paper presents a study of the operating performance of an efficient high power and low cost three-phase and three-level power rectifier as a complementary reactive power source. Simulation and experimental (final version) results are presented to support the above ideas.
Electrospinning is an experimental method of the polymer super thin fibres formation by the electrostatic field. The distribution of electrostatic field affects the effectiveness of the electrospinning. In order to analyze the electrostatic field for given technological parameters the 3-D computer model of an electrospinning device is necessary.
Recently, the increasing requirements and tendencies of higher efficiency systems have caused a substantial impact on electric motor design. Designers tend to change their views on motor topologies to provide the predetermined values of higher efficiency classes (such as IE3, IE4, IE5). Line-start interior permanent magnet synchronous motors (LSIPMSM) are strong candidates for higher efficiency class...
Supercapacitors are characterized by high energy and power density. For those reasons, it is possible to use them as a highly efficient sources of energy. The possibility of using supercapacitors grow along with a reduction in their size while maintaining the above mentioned parameters. The fulfillment of this objective requires the use of modern materials for the construction of ultracapacitors (how...
The topic of the presented paper aims to demonstrate a new principle of hydrodynamic lubrication in mechanical, thermal and electro-magnetic fields. Up till now, when dealing with the hydrodynamic theory lubrication, many authors of scientific papers have assumed the constant oil dynamic viscosity value without variations caused by temperature crosswise the film thickness. Simultaneously, due to the...
There are a lot of systems of carbon nanotubes synthesis. One of the most common is arc discharge system. The disadvantage of this method is its efficiency, repeatability, and control of the system. This work is a proposal of application of an electromagnetic field as an improvement of the arc discharge system. Among different solutions of the electromagnetic field generation, the coil placed on the...
In this paper it is studied the feasibility of using of a self-expandable stent, as an applicator for hyperthermia treatments by magnetic induction. This approach avoids the physical connection of the implant to a generator, and heat is generated from the interaction of the conductor with an applied external magnetic field. The latter induces a current in the section of the stent which, by Joule effect,...
This paper presents computer simulations of ship's magnetic signatures. The influence of ship's inner ferromagnetic devices on the signature was presented. The magnetic fields of the ship's model were calculated in Opera 3D 18R2. The model was built from thin plates. The new, thin plate boundary condition [1] was introduced on all ship's surfaces.
In this paper the effect of the lamination of the magnetic core of an EI transformer is analyzed using a 3D finite elements model, and it is compared with traditional 2D models. It is shown, both in the simulation and in the experimental validation, that the presence of constructive air-gaps gives rise to a zig-zag flux in the z dimension that reduces the magnetic flux in the I-cores and increases...
Induction machines for traction applications are operated at working points of high ferromagnetic saturation. Depending on the working point, a broad spectrum of harmonic frequencies appears in the magnetic flux density of induction machines. Detailed loss analysis therefore requires local and temporal highly resolved nonlinear field computation. This loss analysis could be performed in the post processing...
The article presents the method of calculating the residual induction in transformer columns. The method is based on measurement of the magnetic induction in selected points around the transformer core. The values of residual induction are calculated as linear combination of the results of measurement.
The paper presents the results of an analysis of the inter-turn fault effects on the voltage and current waveform of the capacitor discharge through transformer winding. The research was done within the FAIR project for which a measuring and diagnostic system for testing the condition of electrical circuits of superconducting electromagnets system is being developed. Appropriate measurements and simulations...
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