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Energy parameters of single-phase induction machines
Janáček, Martin ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
The master's thesis deals and introduces a single-phase inductions machines, the principle of operation, types of design and operating conditions. This thesis includes analysis of individual losses in the machine and reduce the possibility of different ways. After a theoretical proposal for reducing losses are measured by mass-produced single-phase induction machine. Further machine modifications proposed for reducing losses in the stator windings and designed a prototype machine with the adjustment of the magnetic circuit to reduce iron losses made by ATAS elektromotory Nachod a.s. The results are supplemented by a simulation using software Maxwell RMxprt and finite element method (FEM). Finally, they are compared to each machines modifications mainly in terms of energy consumption.
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Low power electrical machines
Martinek, Radek ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
The master’s thesis introduces various types of electric motors. Overall, it is divided into 6 chapters, which the first deals with special type of electric motors, namely: permanent magnet DC motor with coreless winding, piezoelectric motor and three phase induction motor with solid rotor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The second part of thesis deals with perspective types of motors, namely: single phase induction motor and reluctance motor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The third chapter deals with analysis parameters of single phase induction motor. The analysis is performed on a borrowed motor from ATAS company by measurement and verification using simulation program Ansys Maxwell. The fourth part discusses the possibilities of increasing the effectiveness of borrowed electric motor. The following is chapter five, which deals with increasing the efficiency of the motor by changing metal sheets. Results are verified by simulations with Ansys Maxwell and measurements on sample of electric motor. The last part presents electric motor design with new selected electric sheets with lower specific losses, but also with lower magnetic induction.
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LOSSES IN MEDIUM VOLTAGE CURRENT TRANSFORMERS
Bajánková, Denisa ; Langerová, Petra (referee) ; Baumgartnerová, Alena (advisor)
Tato bakalářská práce umožňuje nahlédnout do problematiky ztrát u přístrojových transformátorů proudu vysokého napětí. Přístrojové transformátory proudu představují velmi důležitou součást elektrických zařízení, slouží k transformování měřených proudů na standardní hodnoty, které měřicí a jistící přístroje mohou zpracovat. Je důležité, aby tyto proudy byly převáděny s co nejvyšší přesností. Teoretická část práce se zaměřuje na popis přístrojových transformátorů proudu a analýzu jednotlivých ztrát u transformátoru. Praktická část je obsažena v deváté kapitole, má za cíl ověřit teoretické poznatky práce a popisuje laboratorní měření.
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Analysis of steel grade influence on small induction machine efficiency
Plíšek, Oldřich ; Klíma, Jiří (referee) ; Mach, Martin (advisor)
The theoretical part of the bechelors thesis examining the impact of the material of the magnetic circuit on the efficiency of induction motors is devoted to analysis of the induction motor and its losses. It also describes the measuring, including calculations of individual losses. Another theoretical part examines the impact of specific losses on the magnetization characteristics of assessed laminations. The practical part includes laboratory measurements of single phase and three phase motors ATAS Electromotory Náchod brand with multiple types of laminations. Measured values are used to calculate individual losses, which are later mutually compared. Models of measured motors with multiple types of laminations are simulated with the aid of ANSYS Maxwell RMxprt program. Analysis of engines with specific types of laminations are performed with the aid of analytical calculations. Results of calculations are compared with simulated and measured values.
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Design, optimization and full load circuit simulation of the surface mounted permanent magnet machine
Bláha, Martin ; Ondrůšek, Čestmír (referee) ; Kurfűrst, Jiří (advisor)
This thesis deals with the possibility of using the finite elements method for the analysing of synchronous permanent magnets machines. The aim of this work is to discuss the possibility of the machine design more effectively with using the finite elements method and Maxwell software for the simulations. On the created parametric model, simulations were performed according to master thesis assignment. The aim of this work is to determine induced voltage, iron losses, machine inductances and make a permanent magnets demagnetization analysis. From simulations results the machine efficiency is calculated. The parametric model was used for the optimization of selected parameters. From results of optimization new dimensions of permanent magnets was obtained. Machine efficiency was increased by new permanent magnet material and optimized design.
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Analysis of core loss of a small induction machine
Plíšek, Oldřich ; Cipín, Radoslav (referee) ; Mach, Martin (advisor)
The aim of this master´s thesis is to analyze core losses of a small induction motor. Analyzed values are obtained from laboratory measurements, software analysis and 2D finite element method simulation. The theoretical part of this thesis consists of two parts. The analysis of the higher spatial harmonics presents in the induction motor and the analysis of core losses of the motor. Practical part consists of laboratory measurements according to ČSN. Measured values are used to calculate individual losses. The next part consists of creating a model for software analysis (Maxwell RMxprt). The generated model is converted into a 2D simulation environment (Maxwell 2D), where it is adapted to obtain values from the examined parts (rotor and stator teeth and rotor cage). Results of simulations at different loads are compared and analyzed from the point of view of higher harmonics.
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Induction motor powered from inverter
Fiala, Petr ; Huzlík, Rostislav (referee) ; Ondrůšek, Čestmír (advisor)
This master’s thesis studies additional losses generated in the induction motor powered from inverter. The first chapter was used for literature search and it mentions valuable publications. The second chapter discusses the different types of losses in the induction motor. The third chapter describes other negative effects on motor caused by inverter, the fourth one defines possible measuring methods, which would lead to the quantification of additional losses. The fifth chapter introduces the electromotor tested as well as the measuring instruments used. The last chapter presents pivotal results of the measurement in the testing room.
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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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