Virtual Alternator Rotor (VAR) Project

[wattsup]

Hello all.

Hope this is in the right section. If not Stefan please do your magic.

I have been working on my RV system and had taken apart my Delco Remy car alternator to verify some things and then I got an idea.

Looking at the alternator parts, I realized that the stator is an already existing structure that is already proven it can produce 12 volts at 108 amps = 1296 watts. So when the stator receives the proper rotor field and rotor rotation of approx 1750-3600 rpm, it will produce 1296 watts.

Of course this is given the rotor magnetic field creates enough tension and speed on the stator.

Now what if I reproduced the rotor action virtually?

As seen in the pictures, the rotor has two rows of five triangular iron protrusions and there is one internal rotor coil. When the coil is energized as per their proper polarities, the top five triangles have a south field and the bottom five triangles have a north field. The triangular form is chosen because both have their tips towards the center thus making a permanent north/south magnetic field that rotates across the stator windings.

So what if I made 10 triangular coils to replace the iron triangles, 5 top wound in one direction and five bottom wound in the opposite direction. Better still, I could make three coils per triangle that are spread out to cover the empty spaces between the original rotor triangles so as to maintain a more realistic magnetic field movement.

I have provided a drawing to explain the general idea.

I am thinking that it is not really a rotation in the 360 degree sense but more of a switching on and almost off. What I mean by almost off is that the current, I figure (but could be wrong) would be about 33% - 66% and 100% of the applied current when switching the coils.

First of all I will not discuss about switching in the sense of hertz but in degrees. There are 30 coils so each coil would be activated in increments of 12 degrees. So each set of three would be simultaneously activated as follows;

At 00 Deg. 1-100% & 2-33% & 3-66%
At 12 Deg. 1-66%  & 2-100% & 3-33%
At 24 Deg. 1-33%  & 2-66% & 3-100%

The object of this coil fluctuation is to try and simulate the rotation of the original energized rotor, which is again a know structure that when turned inside a known stator will produce power.

This is not re-inventing the wheel but taking what already works and trying to adapt it to work without actually rotating.

What I need from any of the EEers is to design a circuit that can rotate current to the coils in the manner above, or in a manner that may be even better after discussions here.

I will build the rotor but have no aptitude to design the circuit. Hopefully the circuit could have a few more frills for variable control of the switching speed, etc., but this I leave up to all of us to discuss.

I am figuring that 100% voltage would be about 6 vdc at 3 amps, with switching of coils 1, 2 and 3 happening from about 25 to 100 times per second.

There is another possibility and that is to simply rotate the current from one coil to the other, right through the 30 coils at around 3600 or more cycles. There are many other mixes possible but in general, the above method would be a good place to start.

I will keep the Post #1 updated with any changes.

[runaway]

Hi.

I have also done some work with running a car alternator as a motor as in the attached google link below.
you dont need much input power into the rotor winding and actually it will run very well with this winding shorted out.!
All you need to drive it, is a H bridge FET circuit and have variable frequency control, and just wire it as in RV mode. becuase of the low voltage you will need a couple thousand microfarad on the circulating phase, and the way i did this was with 2 electrolytics back to back with diode protection across each one.

Cheers Phil....


http://video.google.com.au/videoplay?docid=3754961939621506331&hl=en-AU

[wattsup]

@runaway

Thanks for that RV alternator link.

But, the project above involves making a power producing alternator without a rotating rotor. Meaning the rotor does not turn. The virtual rotor will turn a magnetic field but not physically turn.

I'm into RV also so your link is very welcome. Thanks again.

[IronHead]

MEG or motionless electric generator
I am very interested in your work here wattsup

[i_ron]

Hello all.

snip

Now what if I reproduced the rotor action virtually?

As seen in the pictures, the rotor has two rows of five triangular iron protrusions and there is one internal rotor coil. When the coil is energized as per their proper polarities, the top five triangles have a south field and the bottom five triangles have a north field. The triangular form is chosen because both have their tips towards the center thus making a permanent north/south magnetic field that rotates across the stator windings.

So what if I made 10 triangular coils to replace the iron triangles, 5 top wound in one direction and five bottom wound in the opposite direction. Better still, I could make three coils per triangle that are spread out to cover the empty spaces between the original rotor triangles so as to maintain a more realistic magnetic field movement.


I will keep the Post #1 updated with any changes.

Hi Wattsup

Good start. But I wonder if you are not placing too much emphasis on the triangles?
This is an artifact of construction. To make a magnetic finger across the inside of the
stator they have had to make it very robust to stand the 'centrifugal' forces. To do this they have had to make the tip very light and make the base of the finger very thick.

In your build you do not have these restrictions and can can just use a straight
finger coil providing you preserve the proper spacing. The only consideration then
is sometimes the angle of the stator, or the rotor, is at a slight angle to ease cogging.

Regards

Ron