|
|
Design of MV contactor for railway application
Pala, Lukáš ; Šimek, David (referee) ; Valenta, Jiří (advisor)
In the introduction a traction circuit is analyzed with different types of electric devices. The thesis describes power railway electric circuits, their loads and types of used contactors. Railway standards chapter summarizes requirements of standards for railway contactors. Follows literature focusing on power current switching and power switching devices design. Based on previous, a design procedure is developed for railway MV contactor in accordance with end-user and standards requirements. Thesis closes with pre-designing a railway contactor by calculating electrodynamic forces, heatflow and mechanical components.
|
|
|
Usage of high-speed camera in the area of switching arc
Samohejl, Matěj ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This bachelor´s thesis is focused on optimizing recording of electrical switching arc in magnetic switches by high-speed camera. Measurements were performed on the circuit breaker 10B without removed side case, which was subsequently cowled by neutral density filter. The voltage and current of the circuit breaker contacts were acquired by measuring system of the Laboratory of switching arc diagnostics. The energy source was motor-generator with a nominal power 16 MVA and test bench consisting of a capacitors and inductors, which have been tuned to the resonance frequency of 50 Hz. Evaluation of the measurements was taken with regard to the brightness distribution levels of the record. Results showed that the mean brightness value varies on the square of the current passing through. For proper localization of the arc, it is necessary to appropriately set the camera exposure. The main problem usually is to darken the scene enough. It was found that it is necessary to take into account that brightness level change depends nonlinear on the exposure offset. The thesis gives a proposal to determine the exposure shift of the record. The possibility of usage high-speed camera to determine the temperature distribution in the arc using the brightness equiintensities was also designed. There are mentioned suggestions how to improve recording of the arc in circuit breakers, especially in the arrangement of the optical parts.
|
|
|
Design of MV contactor for railway application
Pala, Lukáš ; Šimek, David (referee) ; Valenta, Jiří (advisor)
In the introduction a traction circuit is analyzed with different types of electric devices. The thesis describes power railway electric circuits, their loads and types of used contactors. Railway standards chapter summarizes requirements of standards for railway contactors. Follows literature focusing on power current switching and power switching devices design. Based on previous, a design procedure is developed for railway MV contactor in accordance with end-user and standards requirements. Thesis closes with pre-designing a railway contactor by calculating electrodynamic forces, heatflow and mechanical components.
|
|
|
Usage of high-speed camera in the area of switching arc
Samohejl, Matěj ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This bachelor´s thesis is focused on optimizing recording of electrical switching arc in magnetic switches by high-speed camera. Measurements were performed on the circuit breaker 10B without removed side case, which was subsequently cowled by neutral density filter. The voltage and current of the circuit breaker contacts were acquired by measuring system of the Laboratory of switching arc diagnostics. The energy source was motor-generator with a nominal power 16 MVA and test bench consisting of a capacitors and inductors, which have been tuned to the resonance frequency of 50 Hz. Evaluation of the measurements was taken with regard to the brightness distribution levels of the record. Results showed that the mean brightness value varies on the square of the current passing through. For proper localization of the arc, it is necessary to appropriately set the camera exposure. The main problem usually is to darken the scene enough. It was found that it is necessary to take into account that brightness level change depends nonlinear on the exposure offset. The thesis gives a proposal to determine the exposure shift of the record. The possibility of usage high-speed camera to determine the temperature distribution in the arc using the brightness equiintensities was also designed. There are mentioned suggestions how to improve recording of the arc in circuit breakers, especially in the arrangement of the optical parts.
|
guest ::
