The pricniple of numerical simulations is quite simple. In some from CAD programmes 3D object model is created. It can be a contactor, circuit breaker, generator, motor, isolator or switch with fuses or even whole switchoard. To the individual model of objects material qualities are assigned and whole issue is solved thanks to compuiting software in ordinary PC, notebook, work station or even in supercomputer. After solution the images of various physical poles arise (electromagnetic. magnetic, electrical, thermal, streaming) and the computation is finally technically evaluated. With numerical modeling and simulations a lot of high qaulity student thesis dealt. Three of them are described below.
“When it is windy, it turns. When it turns, it shines.”
The first thesis is dealing with a concept of windy powerhouse with vertical axis of turning. The base is windy motor with oblique paddles that is mechanically joined to synchronic generator. This small powerhouse can use for public lighting supplying as you can see in front of VŠB-TUO canteen. To be selfsufficient is fine. Moreover, each electrotechnician should have at least one powerhouse at home.
“Who does not refrigerate, then burns.”
The second thesis is focused on an optimalization of electric motor refrigerating. Why do we refrigerate electrical machines after all? Because electric motor is a machine in real that exchanges electrical energy for mechanic one and does its work on a shaft. During this exchange of energy from one on another one losses always arise. And these losses are heat itself that has to get out from electrical mechine. The better we refrigerate, the machine has lower temperature. A liquid nitrogen or dry ice isn´t necessary, only fan is needed on the shaft.
“When a circuit does its work as it should.”
A study project or a favourite lab task of all students represents a process in which burning gases from an exhaust circuit shoot in a passage of faulty electric current and explode faulty fuses. Maybe you are wondering where the numerical methods, simulations and computers are. All you can search in the blue tinny box on the picture. This is a short circuit generator that creates faulty electric current of approximately 1,5 kA. A value of inductive coil was here computed by numerical methods and the coil together with capacities gives a needful frequency to electric currect 50HZ. The small “computer”, PLC relé, takes care of a correct procedure of operrations to make the short circuit generator functional and safe for service. The task tests the quality of circuits from the security point of view of secured circuit from impacts of the short circuit current.
