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Vibrodiagnostics of electrical machines
Petráček, Samuel ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This bachelor's thesis deals with getting to know vibrations and their description. What types of vibrations occur, what are their parameters, such as deflection or acceleration, and a slightly described frequency analysis for non-harmonic signals. Subsequently, the sources of vibrations in electric rotating machines are described. Types of vibration sources are described here, for example of mechanical origin or on the bearing. The causes of their occurrence are, for example, rotor imbalance, rotor misalignment or mechanical loosening. And their subsequent effect on the machine in axial and radial directions. Furthermore, the Crest Factor measurement method and a summary of other diagnostic methods of vibrodiagnostics such as Envelope Analysis and Kurtosis Factor are described. For what purposes these methods are used and their advantages and disadvantages. In the practical part, 4 asynchronous motors were measured with prerequisites for faults with rotor eccentricity. The effective values of the vibrations and the Crest Factor were calculated here, followed by a frequency analysis using FFT (Fast Fourier Transform). In the end, the resulting data were evaluated.
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Velocity pickup
Konečný, Jan ; Pikula, Stanislav (referee) ; Beneš, Petr (advisor)
This bachelor thesis deals with a proposal of a sensor for measuring relative oscillation of two interacting surfaces. The thesis describes two possible solutions with their advantages and disadvantages, and a patent research. The main part of this bachelor thesis concentrates on inductive position sensor – its attributes and practical proposal.
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Amplifier with Speaker Protection
Přibyl, Libor ; Schimmel, Jiří (referee) ; Kubánek, David (advisor)
The present work deals with the issue of speaker damage due to large displacement of the membrane at low frequencies. The main focus is the design and construction of the circuit to protect the speakers from this type of damage and the subsequent measurement of its parameters. The thesis includes theoretical predictions for the optimal design and implementation of the circuit. The work includes complete construction of equipment, including power supply and auxiliary circuits.
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Vibrodiagnostics of electrical machines
Boháček, Daniel ; Vítek, Ondřej (referee) ; Janda, Marcel (advisor)
This thesis deals with methods of vibration analysis in electric rotating machines. From the beginning, it is necessary to explain the basic concepts and introduce the issue of vibration. Next time, the work is focused on sources of vibration in electrical machines. Defects on electric rotating machines causing vibrations are described. Sensing is performed using sensors of deflection, speed and acceleration. The measured signal needs to be adjusted and filters, approximations and sampling will cover this in the next chapter. The main objective is the methods of analysis, which include the best known in the field of frequency analysis (FFT) and the envelope method in the time domain. This includes other methods such as Kurtosis factor, Crest factor, etc. There is also a basic block diagram for measuring vibrations. This block diagram is programmed and has a graphical user interface. The last part is an evaluation of the measured data of the engines.
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Position measurement
Marek, Michal ; Klusáček, Stanislav (referee) ; Beneš, Petr (advisor)
This paper describes the possibility of measuring plane controls deflection. It also analyzed a number of principles displacement sensing. Subsequently, it was chosen triangulation distance sensor and this sensor was carried out measurements.
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Analysis of intracardiac electrogram, depending on transmurality of ablation lesions at catheter radiofrequency ablation of cardiac arrythmias
Žbánková, Alena ; Kozumplík, Jiří (referee) ; Kolářová, Jana (advisor)
Catheter ablation is a unique method for cardiac arrhythmias treatment based on creating spot lesions of radiofrequency energy using intracardiac ablation catheter. Transmurality of these lesions should be achieved for long-term therapeutic treatment effect. The degree of myocardial damage depth is reflected in the parameters of sensed intracardiac ECG. From research studies is evident that the change in morphology and deflection of ablation signal play a key role in the assessment of transmurality. This thesis consists of theoretical introduction to electrophysiology, proposal and realization of methods for objective assessment of transmurality by processing signals in time, frequency and time – frequency domain. The end of this diploma thesis includes the statistical analysis of these clinical dat and comparison of methods.
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Vibrodiagnostics of electrical machines
Boháček, Daniel ; Vítek, Ondřej (referee) ; Janda, Marcel (advisor)
This thesis deals with methods of vibration analysis in electric rotating machines. From the beginning, it is necessary to explain the basic concepts and introduce the issue of vibration. Next time, the work is focused on sources of vibration in electrical machines. Defects on electric rotating machines causing vibrations are described. Sensing is performed using sensors of deflection, speed and acceleration. The measured signal needs to be adjusted and filters, approximations and sampling will cover this in the next chapter. The main objective is the methods of analysis, which include the best known in the field of frequency analysis (FFT) and the envelope method in the time domain. This includes other methods such as Kurtosis factor, Crest factor, etc. There is also a basic block diagram for measuring vibrations. This block diagram is programmed and has a graphical user interface. The last part is an evaluation of the measured data of the engines.
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Methods of analysis of vibration signals
Sivera, David ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The aim of the thesis is to focus on the different methods of analysis of vibration signals. Focusing on the physical fundamentals of vibrations and a description of their origin in an electrical machine. Describe the vibration sources from mechanical across the electromagnetic to the aerodynamic. Defining the current defects of electric machines and sensors suitable for the measurement of vibrations in an electric machines. Introduction to the methods of analysis of vibration signals in the time and frequency domain. Then using some of these methods for the analysis of vibration signals measured asynchronous motors with different manufacturer defined production defect. The conclusion is composed from the comparison between measured and analyzed results.
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Amplifier with Speaker Protection
Přibyl, Libor ; Schimmel, Jiří (referee) ; Kubánek, David (advisor)
The present work deals with the issue of speaker damage due to large displacement of the membrane at low frequencies. The main focus is the design and construction of the circuit to protect the speakers from this type of damage and the subsequent measurement of its parameters. The thesis includes theoretical predictions for the optimal design and implementation of the circuit. The work includes complete construction of equipment, including power supply and auxiliary circuits.
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Velocity pickup
Konečný, Jan ; Pikula, Stanislav (referee) ; Beneš, Petr (advisor)
This bachelor thesis deals with a proposal of a sensor for measuring relative oscillation of two interacting surfaces. The thesis describes two possible solutions with their advantages and disadvantages, and a patent research. The main part of this bachelor thesis concentrates on inductive position sensor – its attributes and practical proposal.
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