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Losses in induction machines supplied by a frequency converter
Lípa, Miroslav ; Vítek, Ondřej (referee) ; Bárta, Jan (advisor)
Diplomová práce se zabývá měřením asynchronního motoru se dvěma různými zdroji napájení, a to s frekvenčním měničem a generátorem. Tyto dva zdroje napájení byly následně simulovány pomocí metody konečných prvků a porovnány. První kapitola se zabývá popisem asynchronního stroje napájeného frekvenčním měničem a také doporučenými úpravami pro tento druh napájení, aby se předešlo co nejvíce nežádoucím jevům. Druhá kapitola se věnuje ztrátám asynchronního stroje. Třetí kapitola popisuje přístup k měření a vyhodnocování harmonických ztrát způsobených napájením z měniče a také standardizovaný přístup podle mezinárodních norem. Druhá polovina třetí kapitoly také popisuje výpočetní analýzu, která je v této práci použita ve formě analýzy konečných prvků. Nakonec jsou popsány nejistoty měření při použití standardní metody vstup-výstup. Ve čtvrté kapitole je představeno modelování v softwaru ANSYS MAXWELL, kde je nejprve popsána tvorba modelu specifikovaného stroje, poté jeho simulace se sinusovým napájením, a v druhé polovině je vysvětlena simulace s PWM napájením a jak bylo PWM replikováno pomocí naměřených průběhů. V páté kapitole jsou prezentovány všechny výsledky měření s vyhodnocením. Na konci kapitoly je uvedeno srovnání simulace a měření a jeho nedostatečná přesnost.
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Efficiency improvement possibilities of single-phase line-start synchronous machines
Mareček, Šimon ; Klíma, Petr (referee) ; Lolová, Iveta (advisor)
With increase in consumption of electric energy there is also increase of cost related to operation of single-phase induction motors (SPIM), which are mostly used in household applications. This is the reason of focusing thesis to single-phase line-start permanent magnet synchronous machines (SPLSPMSM), which has higher initial costs but also higher efficiency so they have potential to replace single-phase induction motors. That is the reason why the first chapter presents a literary research focusing on the topic of induction machines. The next chapter is dedicated to literary research of used SPLSPMSM and deals not only with their construction but also with transient phenomenon and steady state. Readers will learn about most common used laying of permanent magnets in SPLSPMSM in the next section. Then there continues chapter with possibilities of synchronization increasing because it is an important phenomenon connected with this type of rotating machines. Mathematical model is present in the next section of thesis. There are written equations, which lead to creating an analytical model. An equally important part presents an electromagnetic model and his description, which follows right after mathematical model. There are summarized the most important parameters and their influence on the efficiency of SPLSPMSM in the last but one chapter. In the last chapter there is a comparison between the mathematical and electromagnetic model.
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Coupled modeling of induction motor using finite element method
Gregor, Tomáš ; Huzlík, Rostislav (referee) ; Vlach, Radek (advisor)
This thesis describes complex modeling of asynchronous motor by finite element method. Complex modeling concerns to making models based on different physical principles and their connection. Models are made in Ansys program components and their connection is made in program Ansys Workbench. This thesis includes creating electromagnetic model, thermal model, mechanical model and coupled model which connect partial models.
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Thermal analysis of servomotor
Přibyl, Daniel ; Duroň, Jiří (referee) ; Klíma, Petr (advisor)
This thesis deals with the design of the thermal model of servomotor in program Motor-CAD and using it for analyze of servomotor. In the beginning is a short familiarization about its parts, especially important for the thermal model. Further are described principles of heat exchange. There is a chapter, which is dedicated to the program support of the Motor-CAD. Thermal model and electromagnetic model inputs are tuned according to the measured data. Then a way of active cooling is designed and based of it the model in program is edited. Using the model is found the points of load of the motor for maximum allowable temperature with water cooling. In the conclusion is a valorization of benefit of water cooling for the servomotor.
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Electromagnetic calculation of an electrical machine for Aerospace applications
Halašta, Vítězslav ; Knebl, Ladislav (referee) ; Bárta, Jan (advisor)
This bachelor thesis deals with the electromagnetic calculation of an electrical machine for aerospace applications. Description of the state of art trends that are currently being used in the aircraft industry and requirements for such machines were formulated. Further, electromagnetic model of the machine designed for aerospace applications is created and the electromagnetic calculation using the finite element method is performed. A design process and a comparison of machines designed for this application is also included. The modeled machine was simulated at no load, rated load and faulty condition. Reasons behind the choice of permanent magnet synchronous motor alongside particular steps in design required for machine application in aerospace are presented in the conclusion. There is also discussed, whether the modeled machine is correctly designed for aerospace application.
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Design and optimalisation of synchronous reluctance machine
Bárta, Jan ; Vítek, Ondřej (referee) ; Ondrůšek, Čestmír (advisor)
This theses is related to design of synchronous reluctance motors of the transverse-laminated type. The first part describes synchronous reluctance machine via space-vector theory. Furthermore this part briefly discuss the main design aspects of synchronous reluctance machines. The main part of this thesis is related to practical electromagnetic rotor design for synchronous reluctance machine by means of finite element method. On this base the rotor has been fabricated and placed inside of induction motor instead of his original rotor. On this prototype was made several measurements which were compared with results from finite element method analysis. The last part of this theses is related to short study of synchronous reluctance machine dynamical behaviour under scalar and vector control.
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Constrained modeling of induction motor using physical modeling
Toman, Marek ; Huzlík, Rostislav (referee) ; Vlach, Radek (advisor)
This paper deals with interaction of different physical phenomena in asynchronous motor. The first part of this work is devoted to computing of electrical ratios in asynchronous motor. By using the equivalent circuit in the shape of Gamma-circuit the equation for computing of currents, performances and losses of asynchronous motor are derived. The second part describes calculating of electromagnetic circuit and iron-core losses. In the next part there is the first part of associated model created which respects electric and electromagnetic ratios in the asynchronous motor. This model can be used for example to pursuance of variation of flux density caused by resizing load. In this model the unconventional way of computing the magnetizating inductance and resistance coresponding to iron-core losses is used. The next part deals with calculation of machine warming using the thermal network. In the last part there is a complete coupled model assembed which respects the interaction of electrical, electromagnetical and thermal ratios of induction machine.
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Electromagnetic calculation of an induction machine using an open source program
Bílek, Vladimír ; Mach, Martin (referee) ; Bárta, Jan (advisor)
This bachelor thesis deals with issues of finite element method and its use for electromagnetic calculation of induction machine. The first part of the thesis deals in details about finite elementh method, where the thesis describes the procedure of calculation of electromagnetic model and its use in simulation software. The second part contains and compares the list of paid and open-source simulation programs. The third part describes the creation of the specified electromagnetic model. The fourth part of thesis represents program ELMER, program's posibilites and how to set up scripts for simulation. The fifth part compares simulation results with measurments on real induction machine. The last part is the overall evalution of the thesis.
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Analysis of multiphase electrical machine performance
Kříž, Antonín ; Mach, Martin (referee) ; Bárta, Jan (advisor)
In this thesis, a research on the history and current applications in transport of multiphase motors was conducted. Subsequently, a research on the aspects related to multiphase induction machines was carried out. Finally, the electromagnetic model of six phase induction machine was investigated in the in healthy condition and one faulty phase. The changes of parameters and motion of the motor were compared for both conditions.
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Thermal analysis of servomotor
Přibyl, Daniel ; Duroň, Jiří (referee) ; Klíma, Petr (advisor)
This thesis deals with the design of the thermal model of servomotor in program Motor-CAD and using it for analyze of servomotor. In the beginning is a short familiarization about its parts, especially important for the thermal model. Further are described principles of heat exchange. There is a chapter, which is dedicated to the program support of the Motor-CAD. Thermal model and electromagnetic model inputs are tuned according to the measured data. Then a way of active cooling is designed and based of it the model in program is edited. Using the model is found the points of load of the motor for maximum allowable temperature with water cooling. In the conclusion is a valorization of benefit of water cooling for the servomotor.
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