|
|
Differential and Common Mode Conducted Emissions Measurement
Matýsek, Michal ; Soldán, Josef (referee) ; Dřínovský, Jiří (advisor)
This work deals with interfering signals and noises, possibilities of their measurement, their reduction and afterwards with design of LISN. The theoretical part analyzes formation of interfering signals, their types, with possible measuring instruments for each type of these signals and their properties. In framework of practical part LISN for long-term load of 5A, frequency range from 150 kHz to 30 MHz, with possibility to measure symmetrical and asymmetrical noise separately and also with possibility to switch to normal mode of LISN was developed. For better results LISN was realized as two stage LC filter.
|
|
|
Pre-compliance Electromagnetic Immunity Tests
Růžek, Václav ; Polívka, Milan (referee) ; Soldán, Josef (referee) ; Dřínovský, Jiří (advisor)
The doctoral thesis deals with aspects of pre-certification tests of electromagnetic immunity in the automotive industry. The thesis analyses commonly used test methodology and mentions that standardized electromagnetic immunity tests performed by certified testing centres, which are extremely expensive and represents a considerable time load in the development of the vehicle. The thesis therefore proposes innovative ways for replacement of certification tests with an acceptable level of uncertainty. Key methods are seen in numerical simulations and modified test procedures when the vehicle is exposed by electromagnetic field. The proposed methods are deeply explored and their benefits are discussed and support by number of experiments. The results obtained with the pre-certification methods are objectively compared with the results of the certification measurements by FSV method. The work brings a proposal for a comprehensive test methodology including a discussion of risks and uncertainties with related issues.
|
|
|
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.
|
|
|
Optimization of EMI filter Circuitry
Surovec, Vojtěch ; Soldán, Josef (referee) ; Dřínovský, Jiří (advisor)
In introduction of work, I presented the state of the art of measuring insertion loss of the EMI filter and the description of individual methods of measuring is also included. After that I dealt with global optimization methods and some of them I theoretically described. Mainly PSO method was studied carefully, and the principle of optimization in details are presented in the thesis, because this method was used for optimization of the filters parameters in the thesis. Next part of work deals with theoretical and mathematical expression of insertion loss of the EMI filters. Due to the mathematical expression of the insertion loss, the values of parasitic elements of given filter have been optimized in different measuring systems. This optimization was applied on synthetic data. By this step the functionality of optimization was proved and also the fitness function has been tuned and optimised. The last part of thesis works with optimization on measured data of given filters. I found out inaccuracy in mathematical expression of given model of EMI filter, therefore it was necessary to come up with the new filter model. The accuracy increases by using the new filter model. In next step the new model was enlarged by new spurious components.
|
|
|
Production of a corner sink
Soldán, Josef ; Dvořák, Milan (referee) ; Císařová, Michaela (advisor)
This diploma thesis if focused on the production of a corner sink from stainless steel sheet 1.4301. Based on analysis of manufacturing possibilities the best solution is to produce corner sink by a conventional tool in serval operations, which was the main focus of theoretical part of this thesis. In addition, this choose is in conform with assignment of this diploma thesis. Practical part of this thesis was focused on check of technologicity followed with design of suitable shape of sheet for deep drawing. Further calculation of amount of required draws in specific drawing operations, calculation of drawing forces and works and calculation of parameters of drawing tool. These calculations were checked by numerical simulation which discovered possible defects whereupon the shape of corner sink was modified in order to limit these defects. Based on these calculations the universal drawing tool was designed. In the ending of this thesis the techno-economic evaluation was made which confirmed the economic advantage of this universality.
|
|
|
Virtual Measurement System for the Anechoic Chambers
Váško, Ondřej ; Soldán, Josef (referee) ; Dřínovský, Jiří (advisor)
Master thesis examines a selected part of electromagnetic compatibility. In this work, there is theoretically discussed how electromagnetic interference appears and how is spread through free space environment. To eliminate ambient interference signals, the measurements have been performed in anechoic chamber where the undesirable interference signals were suppressed. In the thesis, there are also described parameters of EMI receivers and limits of electromagnetic interference. The description of calculations of the antenna height for finding maximum intensity of electric field strength for standard measurement distance has been made. For proposed transformed measurement distance, calculations of intensity electric field with addition of parameters measuring antenna and object under test were performed. Correction curves for conversion intensity electric field have been obtained as the result.
|
|
|
The production of cover blowers
Soldán, Josef ; Řiháček, Jan (referee) ; Císařová, Michaela (advisor)
This thesis is focused on the production of cower blowers from steel sheet 1.4541. As the best method for producing of this part was selected bending in the bending press. This choice was based on literature review, geometry of bended part and amount of production order. For each bend was calculated bending force, position of the neutral layer and size of the springback. Bending tools and bending press were chosen depending on the biggest bending force from the bends. Developed length of the part was calculated by the position of the neutral layer. All of the above calculations were numericaly verified by the ANSYS simulation software for the last bend.
|
|
|
Some Aspects of EMC Pre-Compliance Testing
Vídenka, Rostislav ; Soldán, Josef (referee) ; Mazánek, Miloš (referee) ; Dřínovský, Jiří (advisor)
This doctoral thesis deals with EMC pre-compliance testing of radiated disturbance. The thesis summarizes present pieces of knowledge about restricting of disturbing ambient signals and focuses on restricting of test site imperfection influence on the measurement results. Pre-compliance test site “calibration” uses comparison signal sources. There were added up the recommendations for “calibration” steps, too. The semi-anechoic vs. fully-anechoic chambers measurements results were compared. Some methods for dealing with ambient disturbing signals were discussed and high attention was applied to the test site choice and the minimal dimension geometry was recommended. There are presented recommendations for pre-compliance radiated disturbance measurements in the conclusion with the stress on available test equipment.
|
|
|
Methods of technical diagnostics - vibrodiagnostics
Soldán, Josef ; Hammer, Miloš (referee) ; Hájková, Alena (advisor)
The bachelor's thesis deals with technical diagnostics, especially vibrodiagnostics. The work first describes technical diagnostics in general, namely its means and methods, including vibrodiagnostics. The mentioned method is the focus of the presented bachelor's thesis, therefore its description forms the majority of the theoretical part. As part of this work, the vibrations of the electric motor were measured, which were subsequently evaluated according to the standard.
|
|
|
Production of a corner sink
Soldán, Josef ; Dvořák, Milan (referee) ; Císařová, Michaela (advisor)
This diploma thesis if focused on the production of a corner sink from stainless steel sheet 1.4301. Based on analysis of manufacturing possibilities the best solution is to produce corner sink by a conventional tool in serval operations, which was the main focus of theoretical part of this thesis. In addition, this choose is in conform with assignment of this diploma thesis. Practical part of this thesis was focused on check of technologicity followed with design of suitable shape of sheet for deep drawing. Further calculation of amount of required draws in specific drawing operations, calculation of drawing forces and works and calculation of parameters of drawing tool. These calculations were checked by numerical simulation which discovered possible defects whereupon the shape of corner sink was modified in order to limit these defects. Based on these calculations the universal drawing tool was designed. In the ending of this thesis the techno-economic evaluation was made which confirmed the economic advantage of this universality.
|
guest ::
RSS feed.