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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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Calculation of parameters of small induction motor
Vojče, Zbyněk ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This bachelor thesis deals in the first part with a construction and a principle of function of an induction motor. In the second part deals with an actual analytical calculation of three-phase low power induction motor. Is performed a simulation in a program Ansoft RMxprt, which calculated the characreristics of the motor analytically and simulation in program Maxwell 2D by finite element method. The aim of the work is to compare results of simulations with results of analytical calculation.
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DC/DC converters for industrial power supplies
Chudý, Andrej ; Cipín, Radoslav (referee) ; Procházka, Petr (advisor)
This diploma thesis deals with design and comparison of selected DC/DC converters, where the better of them is practically realized. The first part of the diploma thesis is focused on the general analysis of DC/DC power converters. The following part is theoretical analysis focused on the first selected topology – step-up converter. The second analysed topology is forward converter with full bridge on the primary side. The theoretical analysis also includes a description of synchronous rectifier, the differences between hard and soft switching, and the types of secondary rectifiers. Another part specializes in the detailed calculation of main components of selected converters and their subsequent power dimensioning. Both designed topologies are compared according to the required aspects. The selected better topology is supplemented by the design of control circuits and an auxiliary power supply. Practical realization of converter and commissioning follows. The diploma thesis ends with verification measurements on the realized converter and their subsequent analysis.
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Matlab Models of DC/DC Converters
Macík, Tomáš ; Cipín, Radoslav (referee) ; Pazdera, Ivo (advisor)
The Bachelor’s thesis is focused on modeling of DC/DC converters without a transformer using Matlab Simulink software. The first part is dedicated to general explanation of function of selected switch mode power supplies. The second part contains the deduction of equations for every selected switch mode power supply and design of circuit components based on required converter parameters. The models of converters have been created in Matlab Simulink using deduced equations. The models of STEP UP and STEP DOWN converters have been created also using Simscape Power Systems Toolbox and the control of current and voltage has been designed for them.
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Analysis of 1,1 MW permanent magnet synchronous motor
Homolová, Romana ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This thesis deals with the elaboration of The Permanent Magnet Synchronous Motor and the calculation of its parameters. In the first part, the construction and used permanent magnets of this motor are listed here. The next part of the thesis contains a short overview of the stator windings, the calculation of the winding factors and calculation of the basic parameters of the stator winding. The calculation of the magnetic induction in the air gap is also illustrated here. The result is recalculated by using the Carter factor and then the value of the first harmonics of air-gap flux density is determined. The result is compared with the analysis in the program FEMM. The next part of the thesis is creating a comprehensive overview of the machine using a replacement circuit diagram and phasor diagrams. Finally, the thesis contains model created in RMxprt and ANSYS Maxwell. The results of the model analysis are compared with the analytical calculation
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Indirect torque measurement in the output of load drive
Jelének, Marek ; Cipín, Radoslav (referee) ; Ondrůšek, Čestmír (advisor)
For loading of excavator drive units, it is necessary to use electromechanical loads with a high torque up to 16,000 Nm in a low speed range from 0 to 150 min-1 with a maximum output of 50 kW. The electromechanical load consists of an asynchronous dynamometer assembly with a tilting torque measurement system in conjunction with a front three-speed gearbox. The dynamometer is powered by a converter with vector control. To determine the torque at the gearbox output, a correction must be made and the influence of operating temperature and operating speed must be taken into account. Experimental measurement of these influences and dependencies makes it possible to create a mathematical model that can be implemented in the power converter for torque control at the output of the gearbox. The aim of the master thesis is a brief design of the loading drive, design an implementation of experimental measurement of efficiency maps and evaluation of the influence of inefficiency of gearbox efficiency.
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Rotor fault diagnosis of induction motors
Bednařík, Václav ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This bachelor thesis focus on the faults of induction motors. In general terms to mechanical and electirc faults and their influence on induction motor. Further on the tests, that are conducted on induction motors to detect faults and states that precede them. Main part is devoted to rotor eccentricity and broken rotor bars. Eccentricity is solved within theoretical analysis and measurements on free damaged motors. As well as broken rotor bars, which are supplemented by measurements on three damaged rotors. There are two types of eccentricity, static and dynamic. Faults of broken rotor bars is solved in terms of postion of broken rotor bars and their number.
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Step down DC/DC converter with high efficiency
Chudý, Andrej ; Cipín, Radoslav (referee) ; Procházka, Petr (advisor)
This bachelor's thesis deals with design and realization of several versions of DC/DC buck converter. The theoretical part of the bachelor's thesis is focused on the general analysis of DC/DC converters with a detailed description of the buck converters. Another part specializes in the analysis of the current state in this field, where the basic differences between the synchronous and diode rectifier are explained, electromagnetic interference and GaN transistors are described. Subsequently, the thesis involves the design and calculations of necessary parameters of the buck converter. Calculations are verified by simulation and subsequent production of the first prototype. The basic measurements are performed on the prototype. Detected deficiencies of the prototype are removed in version 1.0. In order to achieve higher efficiency, innovated version 2.0 and version with GaN transistors are produced. The thesis is finished by comparing created buck converters.
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