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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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Program for calculation of BLDC motor
Chloupek, Karel ; Janda, Marcel (referee) ; Vítek, Ondřej (advisor)
This thesis focuses on problematics of BLDC motors. Thesis consist of theoretical and practical part. In introduction is the reader acquaint with problematics, principals of development, advantages and disadvantades of BLDC motors. Then folows a description of different types, their realization and construction. Main part of this thesis deals with segment stator. For this type of magnetic circuit was developed computing software. This software will design and provide calculation of motor due to given parameters. In second step, the program generates source code for FEMM software, which provides a simulation. This is the most effective way, how can designer simply verify his calculations
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Design and analysis of three-phase synchronous generator
Šulák, Ondrej ; Ondrůšek, Čestmír (referee) ; Vítek, Ondřej (advisor)
My work will not inform you only about the issue of magnetic field, but also with the design complications and their solutions in the design of electrical machine. In the introductory chapter,I tried to give the most accurate theory of magnetic fields, because to understand that episodes of physical design of the machine is our alpha and omega. Given that the magnetism is nowadays still such alchemiou. The second chapter deals with analysis and design of construction machinery, rotor, stator, as proposed winding, current drive and also shows the results of the FEMM, where I simulate the synchronous machine. Results of the calculations in FEMM, I have recalculate for my own.
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Design and analysis of split-phase induction motor
Nekovář, Martin ; Hájek, Vítězslav (referee) ; Vítek, Ondřej (advisor)
The bachelor‘s thesis deals with the construction, operation principle, design method and analysis of the magnetic circuit of single-phase induction motor with auxiliary phase. The auxiliary phase is considered as winding with series connected electrolytic capacitor. In the first charter is written a general view of single-phase motors. Furthermore, in the following section discussed the design of these machines. Principle of operation as the next section contains an explanation of torque using the theory of two magnetic fields acting against each other. The design method of single phase motor is described the procedure for calculating. Subsequently, two proposals of single-phase induction motor with auxiliary winding were developed according to the method of design and an analysis of their magnetic circuits using the finite element method was made.
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Optimization of Small Electric Machines
Dvořák, Michal ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
Optimization algorithms are highly strong tool for solution of many problems of engeneering practice. They are usually used ,where the solution of given problem by analitics way is strongly unsuitable or unreal. For succesful solution such problems was developed a lot of highly strong algorithms, which alowed solwe dificult problems by efective way. In first part of this work I would like to introduce some optimization methods, their division and application. The next point will be introduction of two programs, which are plentifully used for optimization and each other cooperative together. These programs are ANSYS and MATLAB. In last part I will pay attention to optimization a small electrica machine, which is twelve volts automobile engine starter. On this engine starter I will apply three optimization algorithms and I would try to find corect value of field current for attainment maximum electromagnetic power.
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Engine Motormanagement Software
Kopecký, Ivo ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
Fuel injection is a means of metering fuel into an internal combustion engine. In modern automotive applications, fuel metering is one of several functions performed by an "engine management system". A fuel injection system is designed and calibrated specifically for the type(s) of fuel it will handle: gasoline (petrol), Autogas LPG (also known as propane), ethanol, methanol, methane (natural gas), hydrogen or diesel. The majority of fuel injection systems are for gasoline or diesel applications. With the advent of electronic fuel injection, the diesel and gasoline hardware has become quite similar. During the last twenty years a preparation of a fuel mixture and the way of ignition in engine segment have changed the most. Instead of a carburettor it is being used the unit, which prepare fuel mixture according to a status of a car on the road e.g. change of pressure, temperature or ratio of a fuel and air.
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Analysis of concentrated windings of PMSM
Menoušek, Lukáš ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This thesis deals with the design, principles of permanent magnet synchronous machines and an analysis of their properties. As part of the work is done familiarization with the materials of permanent magnets and their arrangement, as well as construction of the engine where they are discussed types of winding machine configuration, types of motors with permanent magnets and the list of implemented solutions. In the next part of this work is performed analytical calculation of the two types of engines, with concentrated winding, created models based on calculations in FEMM focusing on the creation of spatial harmonics. Further the model in RMxprt and data from the simulations were compared with analytical computation. Finally the model was created in Maxwell and compared with the analytical results of calculation and simulation in RMxprt program. For this model was created analysis of losses in permanent magnets.
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Modeling of torque-speed characteristics of induction motor
Michalík, Marek ; Chrobák, Petr (referee) ; Vítek, Ondřej (advisor)
This master thesis deals in first part with basic theory of an induction motor and principle of function. It also includes theory about higher harmonics of magnetic field and how asynchronous and synchronous torques are created. Various ways how to decrease effect of these torques are suggested. These findings are later applied in practical analytical calculation in second part, in which all parameters of motor are calculated from given dimensions of motor from technical documentation. This is done for basic and higher harmonics. After that a model of this motor was created in RMxprt program, which also calculated all parameters of this motor and created torque characteristic. This motor was also modelled in ANSYS Maxwell 2D. Additional simulations for finding out influence of harmonics on torque characteristic were also done in this software. Torque characteristic of motor was also practically measured in laboratory. All results were compared and evaluated.
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Design of 3 MW high-speed permanent magnet synchronous motor
Bořil, Michal ; Bárta, Jan (referee) ; Vítek, Ondřej (advisor)
The thesis theme is the design of 3 MW high-speed permanent magnet synchronous motor. The work is divided into several parts, and contains the information given on the topic. The first part lists trends and new technologies of high-speed electric machines, and the issues and construction of high-speed synchronous machines are also listed here. In the second part, the machine is analytically designed from the specified values, which is then modelled in the RMxprt program. In the penultimate part, the engine is simulated by programs that are included in the ANSYS Electronics Desktop package, they are RMxprt and Maxwell. The modified engine model in RMxprt is simulated using defined formulas and then converted to Maxwell 2D, where the engine is simulated using the finite element method. In the last part, the results from the analytical calculation are compared with other high-speed machines. In addition, the results of simulations from RMxprt and Maxwell were compared in the last part.
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Measurement of automotive alternators using LabVIEW
Kufa, Daniel ; Aboelhassan, Mustafa Osman Elrayah (referee) ; Vítek, Ondřej (advisor)
This work presents development system LabVIEW and the possibility to create virtual measuring devices. Particular realization of virtual measuring device within the frame of this work is applied on measurement of basic characteristics of claw-pole alternator. The structure and the principle of function of this alternator is described in brief. Created virtual measurement device is described in detail. The entire block scheme, that is the source code for LaBVIEW development system, is attached only in electronic form. The printed version contains front panel of the device and almost all the structures of block scheme.
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