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Electric machines - Contenido educativo
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Well, we are going to study today electric machines. It's a very complicated issue, so you can study deeply in other courses.
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But in this one, we are going to understand the main important things of these machines.
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We can define a machine as a device which can transform energy into work.
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And the machines can be classified, taking into consideration the energy that they need.
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So one of these categories is obviously electrical machines.
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And it's a very important type of machine because we know that energy can transfer but it also degrades, which means that the effectiveness of a machine is less than 100%.
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And for electrical machines, the effectiveness is very, very close to the 100%. And it is the main reason why they are very important in industry and for our daily life.
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We can study, we are going to study firstly the classification, after that the transformer, alternator, dynamo and motors, motors of engines, the translator.
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Well, we can classify the electric machine into two main types, which are statics and rotary. In statics, as the name, as you can imagine, is something that hasn't any movement.
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And the only example of this kind of machine is transformer.
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We very often use rotary machines.
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In this kind of machines there are always stator and rotor.
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And they are the main parts of this kind of machines.
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chains but they will be they could be generators or motor oil engines a
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generators could be also a direct current such as in Amos or alternative
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currents such as alternator. And NGs also can be direct-direct current
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which are going to study this type, just only this type,
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and alternative current that could be tri-phase or single phase or triple
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phase single phase and a triple phase well so let's move on to the first kind
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of machine of this kind of machine which is transformer transformers let us to
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convert the alternative current from the primary to the secondary there are
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mainly a to two circuits with different numbers of a of rings and the result is
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that the the current is proportional to the voltage of the current is
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proportional to the number of rings in each circuit. Transformer just only can
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work in alternative circuit because they are based on the effects of the
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different flux magnetic. It is something that depends on magnetism. So we need
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that the flux evaluation in the flux of magnetic and magnetic flows and it just
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only can be possible if the current is as alternative so it's a good so we
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usually use this kind of device to transfer the voltage of the current in
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in the state of transport this current from the central engine which is produced and generated to our homes.
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Alternator is the machine which can generate electric energy.
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As it's known shows the kind of electricity is alternative electricity, it's changing the polarity in the time.
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To understand the way it works we need to know two effects.
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Firstly, when we have a current, an electric current, the churches are in movement, so they generate always magnetic fields.
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In addition to this, when a magnetic flux can change with time, then an alternative current is generated and this effect is usually called Faraday's Length Loss.
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So, taking this into consideration, in our machine, in our alternator, we are going to have a magnetic field in the stator, which can be generated with a current.
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It can be generated with the current and we also can have some kind of rings of copper
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or so on, which can be in movement because of water or because of the wind or so on.
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So in the rotor we have just only a ring of a conductor, but it is spinning so the magnetic
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flux is changing in the time.
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And this is the main reason why it generates electric alternative current.
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Well it depends the number of magnetic fields we have in the stator.
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This current could be a single phase or three.
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We can change in the rotor, we can change the polarity by using some rings, which usually
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called friction rings.
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The rings can change the polarity at the same time as it changes its polarity.
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So that happens in a dynamo and the result of this is a directed current more or less.
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It's not exactly a directed current but it's very similar to a directed current.
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So it's other kind of generator.
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And finally, rotor. If I have understood how the alternative and the dynamic work,
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it's very easy to understand the motor. The motor as alternative has a stator in which
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there is a magnetic field and a rotor. The magnetic field in the stator can be generated
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by using electric current or a natural material such as iron. And in the rotor we have a lot of
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If I feed the coils with a current, in the rotor is generated a magnetic field, and the magnetic field of the rotor interacts with the magnetic field in the stator.
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As consequence of this interaction, a moment, a force moment is generated and it makes that the rotor spins.
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But, if the rotor spins, the magnetic flux changes with the time, so an alternative current
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is generated and this current is usually called as an electromotive force, and it is the reason
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why the motor, the electric motor, needs more electric energy to move things.
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And finally, obviously, when the rotor moves and it has rotated 180 more or less, the direction
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they could change the polarity so change the direction of the rotation it could be it could
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case at the end that the rotation in rotor couldn't be complete.
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To complete this rotation we use again the Rubin rings, which change the polarity in
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the rotor.
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And now the rotor can rotate 360 degrees and a continuous rotation.
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With this we have finished electrical method.
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I hope it can be useful for you.
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- Idioma/s:
- Autor/es:
- ISABEL LAFUENTE
- Subido por:
- Isabel L.
- Licencia:
- Reconocimiento - No comercial
- Visualizaciones:
- 186
- Fecha:
- 9 de octubre de 2018 - 21:14
- Visibilidad:
- Público
- Centro:
- IES JAIME FERRAN
- Duración:
- 14′ 13″
- Relación de aspecto:
- 1.78:1
- Resolución:
- 1920x1080 píxeles
- Tamaño:
- 286.65 MBytes
