Car Alternator to 3Phase Motor conversion.

[monette999]

Dear Forum,
I am new here,my first posting!

I am working on a recycle project. I like to upscale old stuff.

See my old Alternator from 1970!
I removed the rectifier and wired out the stator winding. They are arranged in a delta configuration.
It has only 70Ah. This was state of art in the last century.

I addition I have bought a 48 to 72V Motor Controller which can handle Sensorless Motors.

On the Rotor I have applied 14V and in use the rotor field windings consum 2.8A.

On highest speed the system takes 300W and each stator phase takes 3A.

So here my question?
During the test without load I have disconnect the rotor current and the motor increased speed and the consumption went up to 400W.

What could be the reason for this.
Is my stator field not optimisés with my rotor field.

I have a learn function on my 3phase motor controller. This piece came without any user manual!

Thanks for the support.
Merry Christmas.

Gesendet von meinem CPH1911 mit Tapatalk

 

[markz]

Did you use it as sensored or sensorless, did you install hall effect sensors or not.

 

[monette999]

I have a sensorless motor

 

[TorgueRPM]

Does the alternator use bearings or bushings?

 

[Stealth_Chopper]

Most alternators have Bushings I believe. ?

And carbon brushes, noun'? , maybe removed from this interesting motor?

Does the alternator use bearings or bushings?

 

[monette999]

It is using two bearings.

But when it got self exited, why it is developing more power?

Thank you.

Gesendet von meinem CPH1911 mit Tapatalk

 

[j bjork]

I am not so sure it is developing more power.
You have weakened the magnetic field and reached a higher rpm.
At that rpm you get higher iron losses and your fan probably uses more power.

If you put more load on it you should get more power with the field coil connected.

I am far from an expert on electric motors, but this is what I think is happening.

 

[monette999]

Here a link to my project.

https://youtu.be/O7ja5Ol3fH4

Thanks for the support!

Greetings
Bob

 

[ShadowNightmares]

Hello for everyone in this thread
Well, about removing the power off the rotor and it speeding up, its because with less magnetic flux on the rotor the speed goes up and the torque goes down, but i don't recommend doing that again, alright?

Installing hall sensors are a bit messy but doable, please check this post where i send a couple of links about it:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=98474&p=1610281#p1610281