|
|
Calculation of electrodynamic forces in 630 A circuit breaker
Staněk, Pavel ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
The aim of this thesis is to simulate the action of electrodynamic forces on current carrying path and a movable contact of the circuit breaker OEZ Modeion BH 630NE. For the calculation there is used the simulation program Ansys Maxwell. The first part is devoted to theoretical analysis of electromagnetic forces on a conductor in a magnetic field. Further I discuss the constructional design of the circuit breaker itself, especially the current path and the contact mechanism. In the next part there is (with using program Autodesk Inventor) created a simplified 3D model of the current path including an arc chamber. With program Ansys Maxwell then there is performed simulation of the acting of forces in each mode. This is magnetostatic and transient analysis for symmetrical and asymmetrical flow of the fault current. In conclusion the results obtained are evaluated and processed in the tabular way.
|
|
|
Electromagnetic field calculation of Induction machine for different mechanical load
Hetflajš, Martin ; Kurfűrst, Jiří (referee) ; Skalka, Miroslav (advisor)
This bachelor’s thesis deals with an analysis of the induction machine electromagnetic field distribution with real parameters. Whole analysis was done for three point of the mechanical load by finite element method in ANSYS. In the next part is described a basic theoretically research of the electromagnetic field and also preliminary survey of the numeric method for FEM. This thesis also contains an analysis of electromagnetic model of analyzed induction machine with detailed description of each analysis step and in conclusion the results summary was done.
|
|
|
Mechanical Torque Analysis of Induction Machine Based on Magnetic Circuit Saturation
Skalka, Miroslav ; Bendl,, Jiří (referee) ; Voženílek, Petr (referee) ; Ondrůšek, Čestmír (advisor)
e main goal of this thesis is mechanical torque analysis of induction machine based on magnetic circuit saturation, oversaturated areas classification and the possibility of oversaturated areas reduction of their influence on machine properties. Whole problem is solved by finite element method in ANSYS program. Work is divided into the description and creating of electromagnetic model, a method of the induction machine equivalent circuit parameters determination, the electromagnetic field calculation by finite element method, experimental measurement using LabVIEW program with measurement accessories (PCIe card National Instruments), data processing program in DIAdem, results analysis of calculations in terms of magnetic circuit saturation, the influence of magnetic circuit material based on electromagnetic field distribution and the magnetic flux density along the air gap including spectral analysis using MATLAB and the electromagnetic torque and its parasitic torque components calculation.
|
|
| |
|
|
Diffraction on Spatial and/or Deep Objects
Hrabec, Aleš ; Petráček, Jiří (referee) ; Kotačka, Libor (advisor)
This discourse deals with a theoretical study of the radiation passage through a diffraction screen with non-zero size in the propagation direction of the radiation, i.e. the radiation passage through a three-dimensional object. Without any loss of generality, we solve the problem for cylindrical cavity in metal. The task exceeds evidently standard scalar theory of diffraction, thus we solve the problem using a waveguiding theory. Following the principles of the electromagnetic theory, we derive required formulae to determine mode distribution at the entry of the cavity. Further, we solve numerically the radiation propagation through the cavity, then we actually seek for radiation distribution at the very end of the cavity. This yields, with a help of the discrete Fourier transform, an intensity distribution of Fraunhofer diffraction pattern, consequently compared with an intesity distribution of the radiation pattern of Fraunhofer diffraction on infinitely thin circular opening having the radius of the cylinder cavity under study. A comparison of such patterns results to a conclusion, that the cavity length has a significatn influence on the diffraction pattern and more importantly, that the scalar diffraction theory appears incorrect for a coherent light passage through cavities longer than their radius squared. Similarly, the same conclusion is inversely proportional to a wavelength of the interacting radiation. Finally, we mention an existence of the so called "focal regime", when the radiation repeatedly exhibits roughly one order increased intensity on the symmetry axis of the cavity.
|
|
|
The Propagation of Electromagnetic Field Inside the Human Tissue
Dostálová, Petra ; Čech, Petr (referee) ; Dlouhý, Jiří (advisor)
This bachelor thesis focuses on the basics of the electromagnetic field diffusion. It describes principle of the finite element method, simulation of the diffusion of the electromagnetic field of the horn antenna and influence of this field on human tissue in COMSOL Multiphysic. Furthermore, it also deals with the calculation of specific absorption rate performance and a comparison of calculated values with the maximum value allowed by ICNIRP SAR.
|
|
|
Visualisation and animation of charge carriers in electrical fields
Kachlík, Jan ; Aubrecht, Vladimír (referee) ; Bušov, Bohuslav (advisor)
This bachelor`s thesis deal with electromagnetic field. The aim of this thesis is acquaintance with physical regularity electric and magnetic field. Especially force effect to charge carriers traveling in these fields. In second part of this project is briefly describe switching arc behavior in high voltage circuit breaker. Principle function is animated in Autodesk 3ds Max 2009. Final point of assignment is create animated presentation about production nanofibres with help of unique technology NanospiderŽ
|
|
|
Model of tissue heating by KV diathermy
Bažantová, Lucie ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This thesis deals with the basic theory of the electromagnetic field in the first part and the field interactions with biological tissues. Than describes shortwave diathermy as a technique used for purposes of medical treatment. The aim is to built a model of tissue heating in shortwave diathermy in COMSOL Multiphysics environment, so there is included a description of the programming environment, including the mathematical method that COMSOL uses for calculations. The output of the whole work is a model of the lower limb in the knee part and display the results after his diathermy heating.
|
|
|
Analysis ofelectrical output from the power plat working in the middle of town
Hrubý, Radek ; Brno,, Luděk Ondroušek - Teplárny (referee) ; Matoušek, Antonín (advisor)
The work focuses on outlet of the electrical power from power plants operating in urban areas. After a short analysis of the general possibility of leading out electric power from power plants of various types, thesis continues to describe of outlet electrical power from PPC Červený Mlýn. Subsequently, are calculated short-circuit conditions in the main switching station. It follows an analysis of power lines. The last part dealt with the issue of reliability of sources in connection with random transition processes in the electrical network and the light of the operational reliability of electrical power equipment.
|
|
|
Electromagnetic field mapping in biological tissues
Bereznanin, Martin ; Dlouhý, Jiří (referee) ; Rozman, Jiří (advisor)
The main objective of this study is to learn about the theory of electromagnetic field and to create a model of propagation of ultra short waves in a biological tissue. Next point of this paper is to determine a specific absorption rate (SAR) using a valid sanitary standard. A particular model solution was realized in a model environment of the program Comsol Multiphysics 3.5. A human head and a cellular phone with an intern antenna were successfully created in this model environment. First of all were entered appropriate parameters which led to a successful representation of the distribution of electric field intensity. A value of specific absorption rate taken by a biological tissue was determined in the next step. This value was compared to the value listed in a valid sanitary standard to prevent its overrun. A development of a temperature in a biological tissue was determined as well, according to a six minutes long interval stated in a valid sanitary standard.
|
guest ::
