|
|
Calculation of electrodynamic forces in 250 A circuit breaker
Görig, Michal ; Dohnal, Petr (referee) ; Valenta, Jiří (advisor)
This master’s thesis deals with the calculation of electrodynamic forces breaker BD250NE305. Main tasks in this semester project is to study the theoretical analysis of individual parts specified breakers. Processing theoretical analysis of these forces. Creating a 3D model current path and sheets quenching chamber single phase circuit breaker in Autodesk Inventor Professional 2012. Another challenge is the subsequent export the model into the simulation program ANSYS Maxwell. After simulation, the specified conditions must be processed and the results of the present work is to evaluate.
|
|
|
The temperature profile of the power switching device of low voltage for different operating conditions
Mejzlík, Tomáš ; Valenta, Jiří (referee) ; Dostál, Lukáš (advisor)
The heat generated in a circuit breaker can be transmitted in two ways: Either through metal parts of current path to conductors outside of device or through plastic parts or air of chassis. The accuracy of the simulation depends on the accuracy of the 3D model and all his parts and it also depends on precise definition of materials with precise definition of electrical and thermal parameters. Electrical circuit breaker has various source of the heat which results in raising temperature of the device above the level of environment. Heat sources are: 1) Joule’s loss of the circuit breaker current path. 2) Heat loss in a bimetal, which is used for thermal release. 3) Resistivity of contacts. This thesis deals with static state of thermal analysis so the sources do not include transient heat source for switching OFF and switching ON. Electrical circuit breakers are made in smaller and smaller forms however their electrical parameters are not decreasing with size. There is logical conclusion that there is more heat on the same unit size which makes thermal analysis of circuit breaker one of the most important part of development.
|
|
|
DISCONNECTOR PARALLEL CURRENT PATHS OPTIMIZATION
Görig, Tomáš ; Tůma, Jan (referee) ; Dohnal, Petr (advisor)
The objective of this master´s thesis is diagnostic the actual disconnector current path that is unevenly stressed by nominal current. The most stressed parts are excessively heated. In next part are projected a few options to optimize the current path. The options are verified by simulation. The best option is recommended to the submitter.
|
|
|
Simulation of phenomena in switchgears
Daševič, Ladislav ; Vávra, Zdeněk (referee) ; Valenta, Jiří (advisor)
Aim of the thesis is to explain the issue of forces acting in circuit breaker caused by magnetic fields induced by short-circuit current. This thesis is focused on force affecting in concrete system of a circuit breaker. The given circuit breaker is made by OEZ Letohrad, the type Modeion BD250. In the thesis the way of creating 3-D model is shown for the purpose of creating numeric simulation by ANSYS 11. The next approach of the thesis is the description of applicating the results for DC and AC current calculations. The noted calculation is made in the programme MATLAB 6.5. The solutions are mentioned at calculations both in the graphic form and numeric specifications. Visualisation was made by using GIF graphic system animation. The individual pictures processing was done in the programme UNLEAD GIF ANIMATOR 5.
|
guest ::
