Register to reply

Electrical generator- governing laws for RPM to voltage output

Share this thread:
mlindeman
#1
Jun21-08, 01:30 PM
P: 3
Hello all,

Is there anyone out there who can help me out?

I have developed a drive system for a generator, but... the big but.... in need to know how to build the appropriate stator for it.

Assume this is of the windmill electrical generating variety, where magnetic coils produce AC current using reverse polarity magnetism.

But.... another big but... the RPM's are around 5000, consistent.

So what are the laws governing the wire gauge, the turns, the number of coils, number of magnets, space between coils, space between magnet, space between magnets and coils.... and all designed for a ridiculously high RPM.

For those of you with the appropriate engineering degrees, and can give me all the answers I need, there will be a monetary remuneration for credible advice. You can e-mail me through this site.
Phys.Org News Partner Engineering news on Phys.org
Comfortable climate indoors with porous glass
Crash-testing rivets
Customized surface inspection
deakie
#2
Jun21-08, 04:47 PM
P: 61
I think you will find these two sites helpful and may even find links to people who are doing a similar thing....
no point reinventing the wheel if its been done.....

http://www.engineersedge.com/motors/motor_menu.shtml
http://www.otherpower.com/otherpower_wind_tips.html

there are also a few budding forums on alternative energy which are very active and have like minded people ready to follow through on this area of work....

hope this helps.....
RonL
#3
Jun21-08, 05:45 PM
PF Gold
P: 702
Quote Quote by mlindeman View Post
Hello all,

Is there anyone out there who can help me out?

I have developed a drive system for a generator, but... the big but.... in need to know how to build the appropriate stator for it.

Assume this is of the windmill electrical generating variety, where magnetic coils produce AC current using reverse polarity magnetism.

But.... another big but... the RPM's are around 5000, consistent.

So what are the laws governing the wire gauge, the turns, the number of coils, number of magnets, space between coils, space between magnet, space between magnets and coils.... and all designed for a ridiculously high RPM.

For those of you with the appropriate engineering degrees, and can give me all the answers I need, there will be a monetary remuneration for credible advice. You can e-mail me through this site.
Something that might come close to what you described, they also have 3hp cont. duty PM DC motors (that I think are very good, if their not sold out) right at $60.00 US

http://www.surpluscenter.com/item.as...tname=electric

The mount bracket can be removed by unscrewing three bolts that secure it to the housing.

mlindeman
#4
Jun22-08, 01:29 PM
P: 3
Electrical generator- governing laws for RPM to voltage output

Most of what i found through your recommended sites I have already researched quite thoroughly. Especially the windmill generators.

My biggest obstacle seems to come with the high RPM. Windmill generators run at low RPM's and therefore much of what they suggest doesn't take into consideration the wire gauge and turns required to handle both the efficiency and energy loss.

So again, I'm looking for those specifications that will work at 5000 rpm's
RonL
#5
Jun22-08, 03:56 PM
PF Gold
P: 702
Quote Quote by mlindeman View Post
Most of what i found through your recommended sites I have already researched quite thoroughly. Especially the windmill generators.

My biggest obstacle seems to come with the high RPM. Windmill generators run at low RPM's and therefore much of what they suggest doesn't take into consideration the wire gauge and turns required to handle both the efficiency and energy loss.

So again, I'm looking for those specifications that will work at 5000 rpm's
I'm a little confused, if your windmill is turning at 50 RPMs and you have a 100:1 stepup ratio, the motor would be turning at 5,000 RPMs, at that speed the voltage would be around 110v, and your best amperage output would be around 2a or 3a Amps. The output of amps will be related to your blades surface area.

The motor specs again were,

130vdc
6750 rpm
18.5 amps

If given this much power the output is 2.5 horsepower, the duty cycle however is NOT 100%.

Turning it as a generator @ 6750 rpm will give a voltage output of 130AC and 0 up to 18.5 Amps current delivered. The duty cycle of this motor will be determined by the total wattage drawn from it.

If I'm wrong someone will step up with a correction
mlindeman
#6
Jun22-08, 04:11 PM
P: 3
I'll look into this motor, which I believe would probably answer a lot of my questions, but if it has brushes, which I assume it has, then it is not what I'm looking as. I'm looking at something with almost negligible resistance.

Most motors, by the nature of their design with no current running through them have a lot of resistance due to the magnets.

That's why i want to build my own stator, again like that of windmill generators, where the magnets are completely independent of the coils and no wires touching, except for those to the coils of course.

But I understand where you're going with this. You're saying that if I take this motor apart, it would probably give me an indication of what a high RPM requires. It may be worth buying just for the investigative illumination.

Thanks RonL
RonL
#7
Jun22-08, 05:49 PM
PF Gold
P: 702
Quote Quote by mlindeman View Post
I'll look into this motor, which I believe would probably answer a lot of my questions, but if it has brushes, which I assume it has, then it is not what I'm looking as. I'm looking at something with almost negligible resistance.

Most motors, by the nature of their design with no current running through them have a lot of resistance due to the magnets.

That's why i want to build my own stator, again like that of windmill generators, where the magnets are completely independent of the coils and no wires touching, except for those to the coils of course.

But I understand where you're going with this. You're saying that if I take this motor apart, it would probably give me an indication of what a high RPM requires. It may be worth buying just for the investigative illumination.

Thanks RonL
Sorry! I did kinda gloss over what you were saying.
I have about a dozen of these motors that I have used in various way, and almost all were fairly low power applications and none that were precise enough to worry about PM, and brush resistance.

I like them (especially the price), but have not put any to a maxium test.


Register to reply

Related Discussions
Peak voltage output of a generator Introductory Physics Homework 3
What is the formula to solve for RPM to volatage output in a generator Engineering, Comp Sci, & Technology Homework 2
How to get output voltage from the tachometer output Engineering Systems & Design 1
Amplifier voltage output error Engineering, Comp Sci, & Technology Homework 2
Voltage Source with output of OV Electrical Engineering 2