Generator and Alternator principles of operation.

[citfta]

I did not want to interrupt the discussion going on in Floodrod's thread about a solid state generator so I will post this here since UFO wanted my experience in relation to generators and alternators.

The first principle we need to understand is that the speed of the changing field with a fixed input to that field determines the voltage that will be induced into the secondary circuit.  If we maintain a given speed and input voltage the output voltage will be stable.  

The second principle we need to understand is that adding a load on the output of a generator will increase the torque needed to keep the speed up.  On a normal home gasoline or diesel powered generator the governor is all that is needed to maintain a stable output voltage.  As long as the speed is stable the output voltage will also be stable even under various load conditions until we load the generator to the point it can't keep the speed up.

Now all that applies to generators and alternators that have a governing mechanism to keep the speed stable.

 But what if we don't have a stable speed?  Then we have to do something different.  In the old days cars actually had generators on them.  And in order to keep the output stable they had voltage regulators that adjusted the field current to keep the output stable under changing speed or load conditions.

In the 1960s cars started being equiped with alternators.  The basic design of an alternator is more efficient than the older generators.  But again because the input speed keeps changing a regulator is required to keep the output voltage stable.

So the simple rule is current requires torque and voltage requires speed.

I hope this helps.

[Ufopolitics]

I did not want to interrupt the discussion going on in Floodrod's thread about a solid state generator so I will post this here since UFO wanted my experience in relation to generators and alternators.

Thanks much Citfta!

I really appreciate your input!

The first principle we need to understand is that the speed of the changing field with a fixed input to that field determines the voltage that will be induced into the secondary circuit.  If we maintain a given speed and input voltage the output voltage will be stable.

Exactly, that is the way I understand it. 

The second principle we need to understand is that adding a load on the output of a generator will increase the torque needed to keep the speed up. [...]

So the simple rule is current requires torque and voltage requires speed.

I hope this helps.

Yes, indeed it helped.

Thanks Citfta!

Regards

Ufopolitics

[Ufopolitics]

@citfta

Ok, since we are here on the Generator Principles of Operation Topic that you've opened...I have some points I would like to share as to get your opinion...

Let's go to the simplest rotary generator, a single phase, brushed type, two pole exciter rotor

As you and I, as many here know perfectly well the way it works, I would go over it briefly, basically about the way it's Exciter System works.

Basically, on the Exciter or Inductor System we have:

1-Rotor w/shaft which have two coils that projects towards stator the two poles N-S, also the slip rings for brushes attached to shaft.
2- Exciter Feeding Stator Coils.
3- Upper housing with brushes which are connected to a very simple circuit: one electrolytic cap and a diode.

So, the Stator Feed Coils generate AC, and connect to Input of brush circuit -on upper housing- then pass through rectifier to output to rotor coils DC Power.

Point is that a Generator Head is a completely self-POWERED running machine, without the need of ANY external power supply.

So all that Gen Head requires is that we rotate it at a fixed-constant speed, so it will be capable of self-maintaining a constant auto generated power to supply its Exciter plus Output a greater Power for Loads.

Normally these types of generator's exciter system run on 150-200V and 2.0 Amps=400 Watts, and their output can be rated from 800 up to 5000 to 7000 Watts...

And, all we need to do...is rotate its shaft.

When the rotary generator is under load stress, it is understood that it needs to increase speed to compensate for the output demand, as the torque also needs to increase to overcome the stiffened magnetic conditions.

But in a solid-state generator, torque is not required, just speed or frequency increase when loaded, since the virtual field can displace through metal mass without opposition...

So, here that rule you mentioned for amperage rise using torque increase is out of the equation for a solid-state generator, correct?

Now, if we go back to a rotary generator, the fact that a torque increase is required, is basically because the 'magnetic stiffness' or Lenz Law, or magnetic Lockup, that makes rotation harder to move and -of course- torque is required to surpass the lockup force.

In simple mechanics, we have an opposing force to rotation, and then we need to increase the rotation force or torque, above that opposing force, then rotor reaches required speed to maintain a stable and higher output.

So, in your belief, what would be the requirement to increase amperage (above input amps, like a generator does) on a solid-state generator?

IMO, on a Solid-State Generator, like Figuera, all we need is to have a constant speed/Frequency of Field Movement...Plus a CONSTANT POWER FEED to Exciter Coils.

In other words, even our power supplied to exciter coils being constant, we CAN NOT have INTERNAL FLUCTUATIONS (coil to coil transfers, reversals, etc) Which do not keep Magnetic Field CONSTANT IN STRENGTH AT ALL TIME during operation.

HOWEVER, having in mind that by moving this field we can NOT have FLUCTUATIONS (basically, up and downs in currents as on inductance values) on Power Supplied to Exciter Field Circuit, as you have stated on your first post, in order to have a constant stable output.

If we go back to the way a simple rotary generator exciter works as I have described above...the Power to Exciter Circuit is ALWAYS STABLE, without any fluctuations.

I only hope you understand well this long post, but any questions let me know.

Thanks, Citfta for your great support!!

Regards

Ufopolitics

[Classic]

@ufopolitics, I am confused and not sure what you are saying: there is an electric flow generated without changing magnetic flux/strength ?
 I am pretty sure you want to say, there is 1 magnetic flux constant all the time and a second one (or many more) which fluctuate (or changing direction) all the time.

[Ufopolitics]

@ufopolitics, I am confused and not sure what you are saying: there is an electric flow generated without changing magnetic flux/strength ?
 I am pretty sure you want to say, there is 1 magnetic flux constant all the time and a second one (or many more) which fluctuate (or changing direction) all the time.

Hello Classic,

What I am saying is that at the Exciter Coils, mounted on Rotor, which are magnetized on two pole (N-S) generator, the power requirements are that Magnetic Field keeps with a CONSTANT STRENGTH, obtained with a CONSTANT FEED of Power.

The Flux variation is obtained through rotation of an always magnetized (N/S) and powered constantly steady, Rotor.

Ufopolitics