|
|
Nonlinear models of DC machines
Král, Michal ; Mišinger, Lukáš (referee) ; Mach, Martin (advisor)
This bachelor thesis deals with modeling and simulation of DC motors. Four models of DC motors were created, according to four types of excitation ( derivative, serial, compound and separated). These models were designed in simulation program MATLAB & Simulink. Models were adjusted in order to respect magnetic non-linearity. Parameters for simulations were measured on real DC machine and the simulations were executed. This theses focuses on examination of temporary effects and comparing with real measured developments.
|
|
|
Automatic design of synchronous machines
Fiala, Michal ; Mach, Martin (referee) ; Cipín, Radoslav (advisor)
This bachelor thesis deals with problematic of design of synchronous machines. First part is dedicated to descript function and structure of a synchronous machine. The next part describes an algorithm of design of wound rotor and permanent magnets synchronous machines. Based on the described method, the program for automated design of these types of synchronous machines was created in the programming environment Matlab. At the end of the thesis, there are described the results that were achieved within the work.
|
|
|
Impact of rotor on a small induction machine efficiency
Stuchlý, Karel ; Janda, Marcel (referee) ; Mach, Martin (advisor)
The aim of this master thesis is optimization of the rotor in the terms of efficiency. An analysis of the effects of rotor parameters is performed by RMXPRT. A genetic algorithm is created to find the optimal solution. Solutions are evaluated and adjusted according to the results. Measurements on the actual machine are performed and evaluated to verify the functionality of the simulation models.
|
|
|
Direct connection of permanent magnet synchronous generator to grid
Chrobák, Petr ; Mach, Martin (referee) ; Ondrůšek, Čestmír (advisor)
This thesis deals with possibility of direct grid connection of permanent magnet synchronous generator. Main benefits of PMSG are briefly compared with classical synchronous generators. There are mentioned all synchronization conditions and their modification in the case of directly grid connected PM generators. One part of this thesis is focused on the damper winding and transient currents shapes during transient state. There is also solved the effect of damper winding on currents shapes. To simulate the case of direct PMSG grid connection there is composed alternative mathematical model of PMSG. Final part of thesis is focused on the simulation of PMSG and there is also made the simulation of PMSG direct grid connection.
|
|
| |
|
|
Assessment of the design of the new solution sliding contact in electrical machines
Záhejský, Petr ; Mach, Martin (referee) ; Veselka, František (advisor)
The thesis is devoted to assessing the concept of a new solution to the sliding contact in electrical machines. The work is focused mainly on the issue of collector engines, which are almost exclusively used in electric hand tools. Much of the work is devoted to angle grinders, which are usually used in extreme conditions and demands for seamless operation are enormous. In order partial insight into the problems in the introduction are studied phenomena acting on the sliding contact, wear and durability. Then further materials and diagnostic methods for increasing the transfer efficiency brush - commutator brush - ring. The following sections of this thesis is also considered a proposal innovated brush along with the practical verification and evaluation of the suitability of the use of innovative sliding contact.
|
|
|
Use of the preheating by electric arc during laser welding of steels with higher carbon content
Mach, Martin ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
The thesis is focused on the study of the use of electric arc preheating, in this case source WIG, during laser welding of steel with a higher carbon content, specifically for this work steel 1.1191 thickness 2 mm. Based on the calculation of the carbon equivalent, the preheating was determined to 208 °C. The welding parameters were selected on the basis of the first experiments. In the experimental section, the samples were welded with laser with preheating using a source WIG, which were then made to a tensile test, Vickers microhardness, macrostructure and microstructure. By using a second heat source, the heat-affected area of the samples was expanded. Samples that cracked in the middle of the weld during the tensile test were heat influenced by cutting samples. The remaining samples was broken in the base material, thus the weld produced was of good quality. Combination of laser welding with WIG electric arc preheating is a very productive method over conventional methods and one of the few pre-heating solutions for laser welding. These are the initial experiments for the use of the WIG arc for preheating in laser welding, to be followed by further research, mainly for the automotive industry.
|
|
|
An induction machine with solid rotor
Fišer, Jan ; Klíma, Jiří (referee) ; Mach, Martin (advisor)
This master’s thesis is focused on induction motor with solid rotor. The introduction is dedicated to the full analysis of the rotor. Then model of motor with solid rotor was designed in 2D and 3D. Simulations of these models were carried out using the finite elements method. Further in this thesis there are laboratory measurements` results due to the motor`s sample. Based on the results from simulations and measurements rotor modifications have been proposed, which led to improved machine parameters. 2D models have been developed by rotor modifications. These models went through finite elements method`s simulation. In the conclusion of the thesis there are all results from measurements and simulations compared.
|
|
|
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.
|
|
|
Automotive Electric Motors Analysis and Innovation
Vala, Tomáš ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
Electric drives used in automotive industry are often based on standard DC motor as it is widely recognised as mature and reliable technology. The most common applications of DC motors in automotive industry are starters and wind screen wiper motors. Aim of this thesis is to provide design overview of typical automotive DC motor therefore main parts and features of the machine will be described in detail. Main disadvantage of DC motor is „sliding contact“ between commutator and carbon brushes which introduces source of electromagnetic disturbance and requires regular maintenance. Within this project different aspects of DC motor design and innovation are expected to be tackled including examples of loss calculation.
|
guest ::
