|
|
Temperature measurement of an asynchronous motor
Bartoň, Petr ; Deeb, Ramia (referee) ; Janda, Marcel (advisor)
In this thesis there are described methods which are used in order to measure a temperature in electric machines. Whereas there is an influence of magnetic field and mechanical effects in the electric machines it is possible to use only limited number of methods for measuring temperature. These methods can be divided into two basic groups. The first group is being called "contact measurement" and while the second one is "non-contact measurement". Contact measurements are performed by usage of resistant sensors or thermocouples. On the other hand, non-contact measurements are performed by pyrometers and thermal imager cameras. Theoretical values of warming are determined by the FEMM which operates on the basis of the finite element method. In the practical part there are compared several methods whereby asynchronous engine was measured at various loads. Measured values are compared with theoretical values.
|
|
|
Thermal analysis of synchronous machine
Bartoň, Petr ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The master’s thesis deals with analysis of warming and cooling of synchronous machine. The warming is caused by the machine’s losses resulting from the conversion of electrical energy into mechanical energy. There then can be achieved high values of temperature on the machine, which can lead to destruction of the machine. The transient thermal analysis, working on the finite element program Ansys Workbench, is used for thermal analysis. As an appropriate instrument, which serves for flow calculation, a module CFX in the program Ansys Workbench may be used. In the practical part the model for unhampered alternator with current in the field winding only was measured and after that, the measured values were compared with the results of transient thermal analysis. Speed and progress of air flow through machine were analyzed with CFX module.
|
|
|
Classification of transmission channels based on speech signal analysis
Báňa, Josef ; Sysel, Petr (referee) ; Atassi, Hicham (advisor)
The thesis examines the impact of VoIP transmission channel characteristics on speech parameters. It seeks ways of emulating properties of a selected VoIP transmission channel and creating a network emulation environment. Several scripts have been created in the Matlab development environment and used to modify and divide a continuous recording into parts identical to the original speeches, before passing through the transmission channel. Subsequently a database of speech recordings is created, as affected by selected characteristics - jitter, bandwidth, loss. Within these databases, symptoms are sought as the most evident characteristics of the transmission channel. Using correlation, symptoms are selected that are best suited for automated determination of the properties of transmission channel characteristics such as jitter, loss and bandwidth.
|
|
|
Optimization of the cooling of induction machines
Halfar, Ivo ; Dostál, Lukáš (referee) ; Janda, Marcel (advisor)
This master‘s thesis deals with problems of optimization of cooling in electrical machines. This work includes introduction to the theory of mathematical optimization and brief introduction to optimization problems. This thesis deals with using of program Ansys Workbench for the thermal analysis in electrical machines and optimization of their cooling. Thesis contains thermal analyse of specific asynchronous motor with the squirrel cage and optimization of its cooling.
|
|
|
Improvement Power Parameter of Small Induction Motors
Kuda, Roman ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
This master´s thesis treats of all asynchronous motor. The project is about type and distribution motors, about differences between three-phase and single-phase machines and efficiency. In one of the chapters describes a particular type of engine with all the parametersfrom the manufacturer. This engine is completely analyzed and it is measured in detail. Then the project deals with the division, the calculation of losses and subsequent possibilities to increase the efficiency of induction motor. In the last chapter is calculation of single-phase motors, based on the engine produced.
|
|
| |
guest ::
