19/02/23 05:51:45
@study @power-systems
- Understanding the current that gets induced in the rotate by the rotating magnetic field.
- The stator and the rotor are both made of ferromagnetic materials with rivets for conductors to be placed.
- Things are complicated as the induced voltage in the rotor fluctuates until it hits some steady state where the moment is just following the rotating magnetic field.
An electrochemical converter systems has three parts. Electrical energy input = mechanical energy output + increased in energy in coupled field + energy losses.
- Interaction, or energy transfer takes place through a common field. Storing up energy in this field and transferring it.
- If energy is transferred to a magnetic field in a regular iron core type set up, how is it ‘extracted’ for mechanical
motion?
- Faraday’s law.
- Energy stored in an inductor can be built up from the loop rule (Halliday).
How is the current induced in the rotor related to slip frequency?
- When we take the frame of reference of the rotor, if the rotor is a single loop, we’re defining it’s magnetic moment as static.
- From this frame, there is a magnetic field rotating around a ‘static’ rotor loop.
- The emf induced in the loop is .
- Because we are in this frame, the rotating magnetic field seems to be moving at a speed which is it’s speed relative to the rotor.
- This, then gives a relative frequency which the emf is calculated from.
Model of a generator
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Inputs?
- The input could be considered as steam,or some channelled form of heat.
- This input is converted, by a wheel or cylindrical shape into rotational energy.
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Mechanism Electromagnetic to mechanical conversion
- A rotor that is magnetised (in some fashion) is placed in the air gap.
- Through rotation we have a rotating magnetic field that induces current into the windings of the stator.
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Outputs?
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Could just use the equivalent circuit and it’s parameters?
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Are induction generators avoided? Why?