CPEE – AMTEE 2003
Permanent URI for this collection
Browse
Recent Submissions
Item Teaching of EMC problems: the point of high importance(University of West Bohemia, 2003) Hála, AlešIn the paper, it is discussed why, where and what to teach in the EMC sphere. The approach to the problem depends on existing or not existing of the subject EMC in a study plan. It is noted that EMC problems should be mentioned in all electrical related subjects. The best solution for solid students´ knowledge in the EMC sphere is the existence of the special subject "Problems of EMC". The content of this subject is shortly denoted.
Item Teaching of electrical engineering in the bachelor study program(University of West Bohemia, 2003) Dědková, JarmilaThe existing five-years study program at the Faculty of Electrical Engineering and Communication Technology, BUT Brno, has been divided according to the European educations trends into two levels since year 2002. The first level represents three-years bachelor course of study, which can be followed by the two-years master course of study. A structure of the new bachelor course of study and comparison the teaching courses of the electrical engineering with five-years study program are described in this paper.Item New methods of circuit analysis under nonsinusoidal conditions(University of West Bohemia, 2003) Kijonka, Jaromír; Henzl, Ctibor; Orság, PetrThe paper deals with a new method of an integral transformation of alternating nonharmonic periodic functions. The presented new methods serves to circuit analysis under nonsinusoidal conditions. This approach is based on the electromagnetic physical laws: Ohm´s law, induction law, equation of continuity, Kirchhoff´s laws and the mathematical definition of the scalar product of the time varying quantities.Item New concept of electrical engineering education(University of West Bohemia, 2003) Sedláček, JiříThis paper describes new concept of Electrical Engineering high - school education at the Department of Theoretical and Experimental Electrical Engineering, Technical University Brno. The methodology, some problems, didactical aspects and experience by performance of lectures, numerical practises and laboratory education process are here very briefly presented.Item Mechanical forces analysis in electrostatical field of the plate capacitor(University of West Bohemia, 2003) Franek, Jaroslav; Bojna, IvanThe paper deals with the origin of mechanical forces acting on the boundary of different dielectric materials in the electrostatic field of a plate capacitor. Boundary effects of the plate capacitor field cause the force dragging the dielectric plate into the air capacitor.Item Interactive course in electromagnetic field theory on the internet(University of West Bohemia, 2003) Jerhotová, Eva; Macháč, Jan; Pankrác, Vítězslav; Spálený, PavelThis paper summarizes particular results achieved while working on Interactive Course in Electromagnetic Field Theory on the Internet project, which received funding for 2003 from the "Fond rozvoje vysokých škol" under grant no. FRV2449/2003. The aim of the project is to create and to present on the faculty server an interactive course in electromagnetic field theory. Students can gain practical experience and improve their knowledge of the subject. The final aim is to improve students´ ability to solve general problems in electromagnetic field theory, which forms the basis of all branches of electrical engineering.Item Expression of the uncertainty of measurement using Excel VBA(University of West Bohemia, 2003) Henzl, CtiborThe technical community always underrates statistical processing of data. However the result of a measurement is complete only when accompanied by its uncertainty. This article originated from documents of BIPM, ISO, etc. for evaluating and expressing the results of measurement. Spreadsheet EXCEL is used in the computation.Item Educational MS Excel application for processing database of measured nonsinusoidal waveforms of electrical quantities(University of West Bohemia, 2003) Orság, Petr; Görlich, Zdeněk; Slavík, PetrThe contribution describes MS Excel program application for parameters determination of an electric circuit in the nonsinusoidal steady state. The parameters of the series or parallel circuit model are calculated over a time period T of measured voltage and current waveforms by means of a new method. The calculated parameters are constant coefficients of an integro-differential equation of the model circuit. The measured voltage and current are acquired by means of the digitizing oscilloscope TDS 420 from Tektronix. Widespread MS Excel environment is utilized for processing and visualization of time waveforms and results.Item E-learning: our experience(University of West Bohemia, 2003) Benešová, Zdeňka; Kropík, Petr; Šroubová, Lenka; Štekl, PavelThe paper deals with e-learning software system for computer supported teaching of the theory of electrical engineering and electrical chemistry with web-based user interface. A MATLAB server communicates with users (students and teachers) through WWW browser. This means that workstations should work on any platform.Item Duality and infinity in theory of electrical engineering(University of West Bohemia, 2003) Preuss, PetrThe paper shows that the physical infinity as an integral part of linear space models is of the spherical shape, exhibits infinite electrical conductivity and carries complementary charge. Given is the original definition of duality and precised the concept of the topological duality. Wider utilization of duality is disallowed due to nonsymmetry of spacial and temporal dependencies.Item Transport of gas components in the cathode of PEM fuel cell(University of West Bohemia, 2003) Kurgan, Eugeniusz; Schmidt, PawełSimulation of the performance of the PEM fuel cell based on the fluid flow approach in electrodes of the proton exchange fuel cell is developed. Gas mixture transport from flow channel to catalyst layer based on Darcy´s law, Fick´s law and ideal gas law is developed. As field variables both concentrations of hydrogen and water vapour where chosen. As a result, mutually coupled nonlinear partial differential equations were obtained. These equations where solved using standard finite element method in two dimensions.Item Gas components transport in the inhomogeneous cathode of PEM fuel cell(University of West Bohemia, 2003) Kurgan, Eugeniusz; Schmidt, PawełIn practical operation of the fuel cell both hydrogen and oxygen can contain some pollute particles as dust, carbon molecules or condensed water droplets. These particles can be together with gas mixture transported to gas diffusion layer where they settle down and clog electrode pores. These results in decreasing layer gas permeability and in effect also gas mixture flow. The deposition of these pollute particles is not distributed uniformly over whole electrode but instead concentrates in region, where gas mixture flows into electrode. This results in inhomogeneous distribution of layer permeability. Field equations for this case are formulated and next solved by finite element method.Item A comparison of different methods for the gradient evaluation in the inverse problems of the impedance tomography(University of West Bohemia, 2003) Dědková, Jarmila; Filipová, PetraThe standard approach for the evaluation of the gradient during the optimization process in the impedance tomography is based on the inverse of the global admittance matrix utilizing certain iterative procedure of nodal voltages. In this paper the benefit of the gradient evaluation by different position of the grounding node on the mesh are compared.Item Theory and design of small motors(University of West Bohemia, 2003) Lavrinenko, Vladimir; Ilyenko, Gleb; Danilov, Anatoliy; Kuzin, Nikolay; Goncharov, IgorTheory of small motors was generalized with the purpose to take into account of parametrical phenomenon in machines with magnetic asymmetry. Theory was used for electromagnetic computation of induction motors and direct current motors. The motors design drawings formed with the help of CAD program Pro/Engineer´2001.Item LOW - frequency currents in intermediate DC circuit of voltage inverter(University of West Bohemia, 2003) Danzer, JiříThe work deals with circumstances of generation of low - frequency currents in DC link of voltage fed inverters with asynchronous modulation at DC traction vehicles. These frequencies are insufficiently attenuated by input LC filter and eventually they can correspond to its natural frequency. An analysis if their generation is performed and magnitudes and frequencies are introduced on particular example. An impact of different modulations is also considered.Item Influence of the third space harmonic wave of the magnetic density of currents and torque of induction motor(University of West Bohemia, 2003) Schreier, Luděk; Chomat, MiroslavInfluence of the third space harmonics of stator current layer and field density on properties of induction motors is discussed in the paper. The rise of these waves in connection with zero-sequence component in stator currents is shown. It is proved that the flux corresponding to the third wave of the field density passes through the air gap and can give rise to rotor currents in dependence of rotor winding configuration. Symmetrical component corresponding to the third space waves of current layer results in increasing of machine currents and additional losses. The additional torque is produced by interaction of these components.Item Influence of temperature on operation characteristics of electrical machine with permanent magnets(University of West Bohemia, 2003) Krasl, MilanThe paper deals with the solution of the non-linear magnetic field in a synchronous reluctance machine with permanent magnets. Nowadays, the permanent magnets made from rare earth are preferred. The properties of these magnets are depended on the temperature. There was modelled the operation characteristics T = f (t) - torque T, temperature t. For calculation, a FEM - based software was used. Results of the solution arer discussed in conclusion.Item Indirect frequency converter for the supply of the rotor of the asynchronous motor(University of West Bohemia, 2003) Krasl, MilanThis project deals with attributes of the electric drive with the double fed machine. In the working mode the stator´s winding will be connected into power network and the rotor is supplied by the indirect frequency converter.Item Finite element method analysis of electromagnetic field inside pulsed power generator(University of West Bohemia, 2003) Pitterman, Martin; Fořt, JiříThe paper describes a numerical solution of a transient analysis process, inside a helical microware pulsed generator. The generator function runs for approximately 10ųs. The separated components were verified by mathematical model, which was formulated in integral form. The results of a solution and values were verified by measurement. The supposed peak power of the generator is Pn=10MW.Item Double-cage asynchronous machines under transiente conditions(University of West Bohemia, 2003) Bartoš, VáclavThe paper presents analyze double-cage asynchronous machines, i.e. currents, torque and speed under transient conditions. These types of motors have two concentric cage windings in rotor, which can be full separated or connected by their common ring. Their merits are greater starting torque and lesser current. Disadvantage is smaller pull-down torque.
- «
- 1 (current)
- 2
- 3
- »