National Repository of Grey Literature 7 records found  Search took 0.00 seconds. 
Diagnostics of adhesion of the tram wheel using Acoustic emission method
Skoupý, Martin ; Dočkal, Aleš (referee) ; Klapka, Milan (advisor)
The aim of the thesis is to develop a method of adhesion diagnostics of a tram wheel by monitoring the acoustic emission originating from the wheel-rail contact. Application on a twin-disk test rigs is expected. The possibilities of using both contact and contactless sensors are examined. The thesis is focused on describing the response to varying speeds, angles of attack and the change of adhesion due to the application of water into the contact. RMS and energy of the acoustic emission, kurtosis or Shannon’s entropy were evaluated. It was discovered, that form the low values of the angle of attack (10 mrad) the acoustic emission RMS rises in linear manner with further increase of the angle or speed. After the application of water, the drop of the acoustic emission corresponding to the drop of adhesion coefficient was detected. The transitional states associated with unequal distribution of water were observed following its application and during the contact starvation. This can lead to an undesirable squeal noise. Another transient phenomenon manifested by the increase of acoustic emission activity was observed preceding the contact starvation, its timing corresponds to the removal of oxide layer described in the literature. Acoustic emission therefore proved to be suitable for its study and possibly for the contact starvation prediction.
Automatic Voltage Control of Distributed Generation in the E.ON Medium Voltage Grid
Skoupý, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Content of this master`s thesis is theoretical introduction of the power factor, reactive power and voltage control of decentralised sources of the high voltage in the E.ON distribution network. Furthermore, the thesis deals with possibilities of regulating the power factor and reactive power, carried on above-mentioned resources, in other to stabilize the voltage and overflow control of the reactive power to higher voltage level. The practical part describes how the automatic power factor and voltage control had been put into action by central management control within the headquaters dispatching systém of the company. Following chapter acquaints a reader with information of how the automatic power factor and voltage control had been tested and how it is utilized in practice. In the conclusion the work summarizes results and effects of the power factor regulation and voltage control to stabilize the voltage and the overflow of the reactive power in the E.ON network.
Prospects for electric individual transport
Skoupý, Martin ; Strecker, Zbyněk (referee) ; Mazůrek, Ivan (advisor)
The aim of the thesis was to create a complex summary of the possibilities of the use of electric vehicles in individual transport, identification of the problems connected with the implementation of electromobility and listing the possibilities of their solutions. The thesis therefore dealt with the benefits in terms of emissions production, with the capacity of infrastructure or the trends in transportation. The need of the changes in the system of transportation was concluded based on the gathered information, i.a. greater use of lighter vehicles or shared transport. At the same time, more measures will need to be taken in the field of electricity production, which is still largely dependent on fossil fuels.
Load Flow Calculation of Chosen Part of E.ON 110kV Grid with Analysis of Reactive Power Flow
Skoupý, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Content of this bachelor thesis is theoretic introduction to the steady state of network and optimization of network operation from the viewpoint of reducing active power losses in the electric wiring. Furthermore, the work deals with analysis of the network traffic flow distribution of the active and reactive power and consequences of overflow of the reactive power from the medium voltage level to the high voltage level. The following part includes designing practical involvement of the area and carrying out calculations of its operation in terms of losses. Another chapter is proposition of measures to minimize the overflowing of reactive power in distribution system and its impact on reduction of operating losses in the network. In the conclusion the work summarizes results obtained and the final assessment of influence of reactive power for operation of the network.
Prospects for electric individual transport
Skoupý, Martin ; Strecker, Zbyněk (referee) ; Mazůrek, Ivan (advisor)
The aim of the thesis was to create a complex summary of the possibilities of the use of electric vehicles in individual transport, identification of the problems connected with the implementation of electromobility and listing the possibilities of their solutions. The thesis therefore dealt with the benefits in terms of emissions production, with the capacity of infrastructure or the trends in transportation. The need of the changes in the system of transportation was concluded based on the gathered information, i.a. greater use of lighter vehicles or shared transport. At the same time, more measures will need to be taken in the field of electricity production, which is still largely dependent on fossil fuels.
Automatic Voltage Control of Distributed Generation in the E.ON Medium Voltage Grid
Skoupý, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Content of this master`s thesis is theoretical introduction of the power factor, reactive power and voltage control of decentralised sources of the high voltage in the E.ON distribution network. Furthermore, the thesis deals with possibilities of regulating the power factor and reactive power, carried on above-mentioned resources, in other to stabilize the voltage and overflow control of the reactive power to higher voltage level. The practical part describes how the automatic power factor and voltage control had been put into action by central management control within the headquaters dispatching systém of the company. Following chapter acquaints a reader with information of how the automatic power factor and voltage control had been tested and how it is utilized in practice. In the conclusion the work summarizes results and effects of the power factor regulation and voltage control to stabilize the voltage and the overflow of the reactive power in the E.ON network.
Load Flow Calculation of Chosen Part of E.ON 110kV Grid with Analysis of Reactive Power Flow
Skoupý, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Content of this bachelor thesis is theoretic introduction to the steady state of network and optimization of network operation from the viewpoint of reducing active power losses in the electric wiring. Furthermore, the work deals with analysis of the network traffic flow distribution of the active and reactive power and consequences of overflow of the reactive power from the medium voltage level to the high voltage level. The following part includes designing practical involvement of the area and carrying out calculations of its operation in terms of losses. Another chapter is proposition of measures to minimize the overflowing of reactive power in distribution system and its impact on reduction of operating losses in the network. In the conclusion the work summarizes results obtained and the final assessment of influence of reactive power for operation of the network.

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