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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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Comparison of methods for identification of rolling bearing failures
Kokeš, Miroslav ; Hnidka,, Jakub (referee) ; Klusáček, Stanislav (advisor)
The aim of this master thesis is the comparison of selected methods and parameters for roller bearings diagnostics. Selected statistical parameters are kurtosis, crest factor, and parameter K(t). The other selected methods are envelope analysis, cepstral analysis, and ACEP method. These methods are implemented in LabVIEW software and compared based on noise resistance, computation speed, and overall capability of identifying roller bearing faults.
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Fault Diagnosis of electrical machines using vibrations
Čech, Roman ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The task of this thesis is to introduce the problems of vibrafon sources in asynchronous motor and their effects and risks to the engine. We will classify the sources of vibration, we will focus for the defects of bearings and for dynamic and static eccentricity. The thesis includes vibration measurement for asynchronous motor, analysis and evaluation of bearings defects and eccentricities.
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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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Software generator of test signals for acoustic measurements
Veselá, Petra ; Schimmel, Jiří (referee) ; Frenštátský, Petr (advisor)
The aim of the thesis is to create a VST2 plug-in module capable of generating input signals for different kinds of acoustic measurements. The opening section offers a theorethical overview of various test signals, their parameters and possibilities of their use during measurement. Subsequent divisions are then introducing a description of several methods of acoustic measurements and a brief overview of a VST interface. Last chapter offers the analysis of the created signals and discussion of their potential use in practice.
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Bearing diagnosis of electrical motors
Kratochvíl, Lumír ; Janda, Marcel (referee) ; Vítek, Ondřej (advisor)
This work breaks down the individual phenomena and findings that have as a common denominator the emergence of irreversible processes leading to damage to bearings in electrical machinery and equipment. The introduction describes the basic description and division of bearings with the recommended methods of their basic operation. The following chapters then deal with the individual sources of damage, diagnostics of individual damages, or examine in more detail the accompanying phenomena of bearing damage. In the first practical part of the work, damaged bearings are physically analyzed and their diagnostics is performed on an electron microscope. The second part of the work deals with vibrodiagnostics and the use of appropriate methods to determine the condition of the rolling bearing and then the location of the source of vibration at error frequencies.
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Bearing diagnosis of electrical motors
Kratochvíl, Lumír ; Janda, Marcel (referee) ; Vítek, Ondřej (advisor)
This work breaks down the individual phenomena and findings that have as a common denominator the emergence of irreversible processes leading to damage to bearings in electrical machinery and equipment. The introduction describes the basic description and division of bearings with the recommended methods of their basic operation. The following chapters then deal with the individual sources of damage, diagnostics of individual damages, or examine in more detail the accompanying phenomena of bearing damage. In the first practical part of the work, damaged bearings are physically analyzed and their diagnostics is performed on an electron microscope. The second part of the work deals with vibrodiagnostics and the use of appropriate methods to determine the condition of the rolling bearing and then the location of the source of vibration at error frequencies.
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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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Comparison of methods for identification of rolling bearing failures
Kokeš, Miroslav ; Hnidka,, Jakub (referee) ; Klusáček, Stanislav (advisor)
The aim of this master thesis is the comparison of selected methods and parameters for roller bearings diagnostics. Selected statistical parameters are kurtosis, crest factor, and parameter K(t). The other selected methods are envelope analysis, cepstral analysis, and ACEP method. These methods are implemented in LabVIEW software and compared based on noise resistance, computation speed, and overall capability of identifying roller bearing faults.
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