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Electromagnetic field scanner and its utilization in EMC measurement
Chupáč, Michal ; Číž, Radim (referee) ; Kubánek, David (advisor)
Master’s thesis is focused on making the acquaintance of EMC issues and ways of electromagnetic field scanner RS321 utilization for pre-compliance measurements. First part contains analysis of available equipment’s influence on measurement results on the basis of gathered specification. Next part includes an example measurement used as operational manual for scanner and its controlling program. The most important part is correction evaluation for performed EMI measurement of signal generator using its EMC certification protocol and application of gained correction curve on independent EMI measurement of device tested by EMC testing laboratory. Other possibilities of scanner utilization are mentioned in the next chapters. Last part of the thesis contains suitability evaluation of EMC scanner on the basis of findings from performed measurements.
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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.
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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.
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2D and 3D Simulation of Electric Fields of MV Source
Kováč, Martin ; Hruška, Ivan (referee) ; Orságová, Jaroslava (advisor)
In the master´s thesis author deals with simulations of electromagnetic fields and their applications in the electric practice at the design of electromagnetic devices. The first part of thesis deals with 3 electromagnetic field simulation softwares, their comparison and selection of the best software for the practical part of the thesis. The second part contains the practical applications of electrostatic and electromagnetic field simulation of HT power supply.
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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.
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Numerical method for computing electromagnetic field
Bíreš, Pavol ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
The aim of the work is to study the electromagnetic field theory, finite element method and the interaction of electromagnetic field with tissues. Gained knowledge is then used to calculate spreading of the electromagnetic field in the microwave field and to create a temperature profile of spreading the electromagnetic fields in human tissue. The finite element method was implemented in the Matlab programming environment, where the 1D model was created in the frequency and time domain and a simple 2D model created in time domain. The program was developed to analyze spreading electromagnetic wave. Another part of work was done in the programming environment of COMSOL Multiphysics. In this case was the human leg exposed to electromagnetic fields. The analysis determined the changes of temperature in these biological tissues for six minutes.
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Simulation of toroid coils in Ansoft Maxwell 3D
Daněk, Michal ; Pfeifer, Václav (referee) ; Hanák, Pavel (advisor)
The master thesis is focused on the simulation of the toroid coils in Ansoft Maxwell 3D software, which uses finite element method for electromagnetic field simulation. Firstly the process creation of the geometric model toroid coil with seventy-five threaded is presented. It is necessary to debug this model and prepare it for the mesh generation. Physical properties are assign to this model and it gives rise to the physical model. We will set boundaries, excitation current, core material, winding material and the parameters for the mesh generations. New material Kashke K4000 will be created in the materials library and subsequently we will define its BH curve on the basis of datasheet. Analysis is made in two modes. Direct currents (7,5A; 10A; 15A; 20A; 25A) and (non)linear materials are used in magnetostatic solution. Toroid coil is excited by current pulse in transient solution. In Ansoft Maxwell Circuit editor a source which generates current pulse will be created. This excitation will be assigned to the toroid coil as an extern source through a terminal. Core material is linear in the case of transient analysis, because Ansoft Maxwell 3D doesn´t allow to use nonlinear material in this solution. Settings are different in transient and in magnetostatic analysis. End time and time step are entered to solve this task in transient analysis. Time points are entered too. Flux density and electromagnetic field strength are calculated in these time points and later it will be possible to view the results. Calculated fields are shown as the pictures in this thesis. The procedure how to use a field calculator in the postprocessing is given as well. The achievements are summarized in the conclusion.
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Workplace for HF Radiated Immunity Testing
Slach, Petr ; Soldán, Josef (referee) ; Svačina, Jiří (advisor)
This thesis investigates into possibilities of a design of a workplace for device endurance experiments against strong high-frequency electromagnetic field. It deals with testing methods, describes advantages and disadvantages of such methods. It investigates possibiities of testing devices, possible magnitudes of fieldstrenght. One can find in the thesis a review of a way of testing using a high-intensity electromagnetic field. A concept of a construction of a stripline including a practical example is a part of the thesis.
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Measurement of anechoic chambers
Švec, Marek ; Nováček, Zdeněk (referee) ; Dřínovský, Jiří (advisor)
This Master’s project deals with general aspects and possible solution of effective shielded cover and cell/chamber shielding measurement for needs of electromagnetic compatibility EMC on the basis of available norms and standards. Electromagnetic shielding is one of the most anticlutter means of EMC. Its main task is reduction of disturbing emission at the side of sources of disturbing signals as well as electromagnetic resistance increase at the side of disturbing signal receivers. Shielding is considered to be an important structural means to reduce electromagnetic field referring to a defined space part. Technical means for achieving the given goals are called shielded covers or shielded cells/chambers. Shielding is one of highly effective methods related to electromagnetic protection, for instance against power/output disturbance. To express the shielding quality so called shielding effectiveness SE is used. It represents logarithmic rate of shielding coefficient that is defined by the intensity ratios of electric and magnetic fields in a certain point of the shielded space to electric or magnetic field intensity incident/impinging on the shielded screen or wall.
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