Alternator into BLDC

Z

ZevEst

1 mW
Joined
Jan 19, 2019
Messages
12
First of all, Hello everyone!

So I found this thread related to my problem, but I was unable to notice final solution for that.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=60910

I am using BMW alternator for learning purpose, I am quite strong in electronics but this made my head dizzy.
I've taken out diode bridge, cleaned the alternator, changed brushes etc .. But the problem is that I was left with 6 wires in pairs. I untwisted them and did some measuring, help me to understand how should I connect them. Twist them back together, and then ... or .. ?

IMG_20190119_170322.jpg
 
So as i understand, one side is wired in delta, and the other one also.. the thing i do not understand is, how to wire 2 sides together.
 
Is that the cleaned up coil it look like it's got some age.
With an alternator the coils you have are the start and ends of three phases that can be combined at one end for a wye config or joining the end of each phase back to the start of the next and that is then delta connected.
The rotor with its brushes are connected to a dc supply, what you will find is that a low dc power to the rotor will spin fast with little torque when controlling the three phase side then up the voltage to the rotor and repeat, the motor will be slower but more powerful, when the rotor is at its max power without getting to hot and the stator then you will have max torque and decent speed control normally the rotor is around 12v and the stator 48v from what I've seen but I've never experimented with one if I was going to I'd probery use a vesc 4.12 controller for the stator with a pwm 12v dc controller to modulate the rotor and run it FOC sensorless commutation.
 
Good eye, they coil itself isn't cleaned yet. Was planning to do it after soldering everything on place and while i clean up the flux i will do the rest.

Rotor dc will be controlled via NPN transistor with some nodeMCU microcontroller, so i can tweak it easily.

For controller and test purpose i ordered some cheap chinese 1500W 48V controller.
 
Good luck with it enjoy your potching your on the right track to getting it spinning.
 
You need to use a multimeter and link them in pairs if there's no continuity it's not the end of the coil on test, find the 3 linked pairs then connect them start to end and run a wire for each of these phase's to the esc for delta.

I'd say run it in wye, there will be more efficiency at lower rpm and less no load current, unless you plan on going 8krpm + use wye.
Let me look and get back on the delta connection I've not terminated like that myself I've got wye on all my motors so I need to verify the info I've give is correct.

Yeah I explained it wonky so it come across wrong you find the ends of each phase then you need to link them like you showed end of one phase with the start of the next in a triangle like shown :roll: that is then delta.
 
Ianhill said:
You need to use a multimeter and link them in pairs if there's no continuity it's not the end of the coil on test, find the 3 linked pairs then connect them start to end and run a wire for each of these phase's to the esc for delta.

I'd say run it in wye, there will be more efficiency at lower rpm and less no load current, unless you plan on going 8krpm + use wye.
Let me look and get back on the delta connection I've not terminated like that myself I've got wye on all my motors so I need to verify the info I've give is correct.

Yeah I explained it wonky so it come across wrong you find the ends of each phase then you need to link them like you showed end of one phase with the start of the next in a triangle like shown :roll: that is then delta.
Click to expand...

I'll test it like i showed, so i have like 6 pairs, measured them all, it is drawn on a paper as you can see. Thats the way it is connected, so i guess ill just need to cross them for delta.
 
Congrats, hope you can make a good project out of it lets us nw how you get on.
 
Punx0r said:
IIRC many alternators are 6 phase
Click to expand...

I've never come across one on stock cars but it maybe a thing in the alternators the high power spl 170db wagons, I worked in Bosch many moons ago and the 8 models we had done around 1 million units and the top model done 110 amp for a jaguar x type when they were new, they all used 3 phase, cost I think was the issue the bridge rectifier and smoothing circuit would have to be doubled up and aloy more copper added so they just increased the phase thickness to handle more power.

Ideally one of those heavy duty alternators the jag s the best grab from a scrap yard it would be able of putting down a few kw constantly.
 
What's your plans with it zevest I'm interested to hear what it's going to plan, be it a ball bearing mill or what ever.
 
Well, I have Cagvia Mito 125cc motorbike frame just standing in the corner, so i thought why not. If it doesn't work i will just buy an motor.
Also i have gathered several 18650 cells and so on..

cagiva-mito-mito-125-ev-2000-07-rosso_87364693.jpg
 
Nice little commuter, keep us updated good luck with it be nice if you could keep that look and fit the guts underneath it, be a smart looking ride.
 
Yes, thats the basic idea of keeping the look. Maybe just paint it as green or black ..
Another fun factor is that almost everything is reused or recycled on this project.
 
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