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Bifurcation analysis of electric drive
Mach, Martin ; Vrba, Jaromír (referee) ; Koláčný, Josef (advisor)
This master thesis is deals with phenomenon of bifurcation in DC drive. It contains theoretical part, results of simulations and measurements of real DC drive in laboratory. The simulations was made in MATLAB, their results are bifurcation diagrams for different value of parameters. Target of measurement in laboratory was observed bifurcation on the real DC drive. Results of measurement are too transformed to bifurcation diagrams.
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Analysis and Innovation of DC Motors
Štaffa, Jiří ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This work deals with direct-current electric motor, type P2XR49, by firm ATAS elektromotory Nachod a.s. At first there is an introduction with the principal of running, starting, controlling of revolutions and commutating of direct-current machine. The implementation of direct-current machines contains a construction and a list of machine parts, a type of winding and types of small motors that had been used. It is ordered according to a type of excitation. The work includes detailed procedure of admeasurements of speed-torque characteristic mostly used in practice. There is a large number of machine characteristics. The speed-torque characteristic was measured in constant voltage rating into current rating in the direction of rotation CCW upwardly and CW on strength of current rating. Machine innovation, decrease in volt drop on the commutator, was chosen because commutator is the most problematic part of the machine. If the contact pressure is increased the transition resistance will be lesser and consequently the volt drop on the commutator will be lesser.
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Small Induction Motors
Chvatík, Štěpán ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This bachelor‘s thesis deals with a single-phase induction motor and is organized in five sections. In the introduction is briefly described its construction and compared with three-phase induction motor. The first chapter describes the emergence of a rotating magnetic field of motor, methods of obtaining the starting torque, the influence on properties of different types of motors, comparing the torque characteristics of the different types of motors. In the second chapter is discussed permanent-split capacitor induction motor, its calculation and operational optimization. The third chapter deals with the determination of general principles of calculation and calculation method of single-phase induction motor with auxiliary winding. The fourth part verified the accuracy of these procedures on the selected motor when we performed calculations based on the input parameters of the motor, and after that these calculations are compared with the output parameters which are prescribed by the manufacturer. Verification of the relevance of declared parameters is supported by measurements on the mentioned device and their evaluation.
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Efficiency improvement of single-phase induction motor
Bořil, Michal ; Mach, Martin (referee) ; Vítek, Ondřej (advisor)
The subject-matter of the Bachelor Thesis is increasing efficiency of a single-phase asynchronous motor. The thesis is divided into several parts and comprises information concerning the subject-matter. The first part deals with the theoretical principle of all rotary machines from three-phase motors to single-phase motors, describing the principle, design and functionality of these devices in detail. In the second part, a new motor model is designed on the basis of the label values of a specified asynchronous motor and adapted to have the highest possible efficiency. The model of the motor is created in the ANSYS RMxprt program and compared to a model of the specified motor, which is also created on the basis of parameters of the technical documentation in the same program. In the last but one part of the Bachelor Theses, several models are created with proposed modifications of the motor to increase efficiency and compared to the specified motor. This part focuses on an analysis of individual types of losses that influence the efficiency and power of the motor. In the last part of the Bachelor Thesis, in the ANSYS Maxwell program, a model of the specified motor and a model of the motor with the highest efficiency is simulated with the use of FEMM. The obtained information of the models from the Maxwell program is compared to information obtained from the RMxprt program and evaluated.
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Special small induction motor
Trubák, Vojtěch ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This term paper is focused on theory and calculation of an induction motor with solid rotor. It is divided into six chapters, the first one being an introduction and the last being a conclusion. Second chapter is dedicated to magnetism. There is briefly description of a skin depth of a conductor and calculation method for impedance of a conductive solid. Third chapter is focused on theory of an induction machines, their construction, equivalent circuit and some of their properties. Fourth chapter is dedicated to calculation of an induction motor with solid rotor and its parameters. Fifth chapter is comparing results of calculation done in fourth chapter for an already existing motor with measured values.
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Increase of efficiency of a single phase induction machine
Muczka, Vojtěch ; Klíma, Jiří (referee) ; Mach, Martin (advisor)
This thesis is dedicated to efficiency increase of one phase induction machine through material change of induction cage and rotor slot shape optimization under the condition of maintaining the same locked-rotor torque. In the first part of this thesis is the explanation of induction machine principles. Next is the comparison of measured and simulated parameters of small one phase machine from ATAS company. The following part is dedicated to the analysis of rotor slot shape and ring size influence on machine parameters when using pure aluminum instead of resistive alloy. The next chapter deals with slot shape optimization in the program RMxprt, controlled by genetic algorithm written in MATLAB interface. In the final part are the resultant slot shapes simulated in Ansys Maxwell using finite element method and then the measured, simulated and expected parameters are compared.
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Losses Analysis of Induction Machines with Small Output Power
Mach, Martin ; Záskalický, Pavel (referee) ; Voženílek, Petr (referee) ; Hájek, Vítězslav (advisor)
The main objects of this doctoral thesis are analysis of a small induction motor losses and research of ways how to reduce losses and increase efficiency of this motor. The ways how to reduce losses and increase efficiency under study are as follow: reduction of stator winding’s resistance, lengthening of magnetic circuit, modification of turn number, cooper squirrel cage, slots shape optimization, sheets annealing and use of sheets with lower specific losses. The losses analysis and the research of ways how to reduce losses are done due to laboratory work. For this laboratory work, eleven different samples of the motor with above mentioned modifications were manufactured. Results of their measurements and losses analysis are presented in this thesis. There were also simulations by finite elements method used to help solve objects of this thesis. Due to the simulations, analysis of loses of the induction motor under study was done. Results of this analysis include some details that are not included in the results from measurement, for example separation of core losses between rotor and stator. The simulations were also used for analysis of manufacturing technology impact onto the motor’s performance. During this analysis, following impacts were considered: actual shape of magnetic circuit, stator’s sheets riveting, influence of cutting onto material’s properties and placement of the stator into conductive frame. Results of this analysis are presented in this thesis.
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Analysis of possibilities to improvement induction motors efficiency
Novotný, Jiří ; Hájek, Vítězslav (referee) ; Mach, Martin (advisor)
In the first part of the master’s thesis dealing with the increasing efficiency of induction motors there are briefly presented basic information about induction motors, followed by an overview of the losses of induction motors. The next part deals with the ways to increase efficiency of induction motors without increasing tooling costs. The practical part consists of four measurements of four induction motors, with their various mechanical adjustments to make comparing benefits of these modifications possible. The measured results are compared by a finite element method in Maxwell 2D Design program, in which the same motors are simulated as measured. Theoretical knowledge about the increase of efficiency is practically applied while being implemented in the simulations.
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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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Design of interior permanent magnet synchronous motor
Žák, Ondřej ; Mach, Martin (referee) ; Vítek, Ondřej (advisor)
The thesis describes problematics of synchronous motor with permanent magnets. The design is provided by analytic and empiric procedures. The great accent is placed on the description of the magnetic circuit of the motor. The finite element method analysis of designed motor is performed subsequently. The main target of this thesis is to find the way, how the ferrite permanent magnet should be used in synchronous motor.
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