3 Phase scooter motor as a DC generator

Thread Starter

P Roppo

Joined May 18, 2019
4
Hello all, I am a bit confused. I want to convert a scooter wheel motor, normally running off a 36v battery into a generator for use on a vertical axis wind turbine to recharge the same 36v batteries. The motor is 3 phase. It has been a bit since I tried and iirc, I could see voltage from 2 of the three leads but it made me wonder if I wasn't leaving power behind from that third leg. I understand it may not be the most efficient generator but it is quick and dirty and very cheap, just like me so that's ok. I've looked around but haven't quite been able to get a handle on the wiring. How would you do this?

Thanks for your time.
 

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oz93666

Joined Sep 7, 2010
737
That's a terrible misuse of a very nice , high value item . You are about to find out how rarely the wind blows (in most locations) and how small the energy return from a wind turbines is , and how much trouble they are .... The smallest solar panel will deliver more energy and is so much more sensible

Still .... to your question .. there should be just three wires coming out of your 3 Phs motor ... it's output is just like 3Phs supply from the grid , but at lower voltage .... pick any two wires and you have a single Phs source you can put a full or half bridge rectifier across these two wires to get DC.... You can triple this with the other two combinations to get max power .... But your voltage is dependent on how fast the turbine spins! Not very convenient for charging .
 

Thread Starter

P Roppo

Joined May 18, 2019
4
That's a terrible misuse of a very nice , high value item . You are about to find out how rarely the wind blows (in most locations) and how small the energy return from a wind turbines is , and how much trouble they are .... The smallest solar panel will deliver more energy and is so much more sensible

Still .... to your question .. there should be just three wires coming out of your 3 Phs motor ... it's output is just like 3Phs supply from the grid , but at lower voltage .... pick any two wires and you have a single Phs source you can put a full or half bridge rectifier across these two wires to get DC.... You can triple this with the other two combinations to get max power .... But your voltage is dependent on how fast the turbine spins! Not very convenient for charging .
 

Thread Starter

P Roppo

Joined May 18, 2019
4
Thanks, I know very well about all that, I've been playing with solar and wind turbines on this off-grid property for 28 years and don't need a lecture on energy. At 3,000 ft elevation directly facing the Pacific, if the sun isn't shining, the wind is blowing. A small vertical axis (VAWT) will solve many of the problems of a horizontal axis such as noise, broken blades, accessibility, noise, turbulence, and did I mention noise? It has also been fun to plan and build and can very interesting to look at. I can also scale it up for more motors, they can be found quite cheap.

But I do need lectures on wiring this motor for maximum output. What do you mean by tripling with the other two combinations?
 
Last edited:

BR-549

Joined Sep 22, 2013
4,938
It's difficult to tell anything from that image. I would suggest a way to constantly rotate motor......and verify the 3 phase outputs.

Then you need to rectify them. This will give you a DC bus.

power97.gif


Then you will need a voltage regulator for your application.

This is just a general comment, the motor wiring makes all the difference. Have you doc on motor?
 

oz93666

Joined Sep 7, 2010
737

There we are , you just need six high current diodes

Then you need some circuitry to get the voltage high enough to charge the battery , Step up converter.... all available on eBay ...

I'd still be willing to bet even at the windiest location you'd be better off expanding your collection of solar panels ...

Please report back in 6 months reporting how many KWHrs of wind energy you produce in a week ...Good Luck
 

Thread Starter

P Roppo

Joined May 18, 2019
4
Thank you for that information. I have subsequently found others using these motors, the keyword was 'hoverboard' rather than scooter motor. They are 3-phase and It is suggested to just use an old alternator rectifier to convert to DC. So then of course the first thought was to just use the alternator from which the rectifier came but these little hoverboard motors are apparently far more efficient unless the alternator is rewound. Makes sense as the hoverboard is running on valuable battery-stored energy.
As for the opinion more solar panels would be better, they don't do enough when the clouds don't break for a week or three but the wind is blowing constant. This eliminates the need for even more batteries when the tenants want to run the furnace and also the roof cannot hold more than the 4kw it already holds. Plus, I get to play with something.
Thanks.
 

shortbus

Joined Sep 30, 2009
8,971
So then of course the first thought was to just use the alternator from which the rectifier came but these little hoverboard motors are apparently far more efficient unless the alternator is rewound.
While kind of the reason the real reason is the 'hoverboard ' motor is a BLDC, it has magnets in it's rotor. An alternator needs a battery to make it's magnetism since it's rotor is electromagnetic.
 

GHAFARY

Joined Oct 2, 2021
2
Hello all, I am a bit confused. I want to convert a scooter wheel motor, normally running off a 36v battery into a generator for use on a vertical axis wind turbine to recharge the same 36v batteries. The motor is 3 phase. It has been a bit since I tried and iirc, I could see voltage from 2 of the three leads but it made me wonder if I wasn't leaving power behind from that third leg. I understand it may not be the most efficient generator but it is quick and dirty and very cheap, just like me so that's ok. I've looked around but haven't quite been able to get a handle on the wiring. How would you do this?

Thanks for your time.
HI ,You can simply buy SQ SQL5010 1000V high current three phase rectifier bridge 10A 20A 30A 40A 50A fast recovery diode rectifier laser diode module and connect it to the 3 phase of the wheel and the other 2 line to the charger controller .watch this video
. hope i could help you
 

Reloadron

Joined Jan 15, 2015
6,227
The top of your image reflects 3 of what I guess to be hall effect sensors with outputs labeled A, B, and C. Those are not needed. A few years back I was looking at making a voltage regulator for my bike. Measuring from Phase A to B, B to C and C to A you should be seeing an AC voltage? Three phase so three voltages AC. On the motor you have I am not sure if they use a field winding? During my experimenting with my little project I used one of these as my 3 phase rectifier. Inexpensive and worked just fine. Connect as in the post #6 schematic or in the above video.

Ron
 

GHAFARY

Joined Oct 2, 2021
2
The top of your image reflects 3 of what I guess to be hall effect sensors with outputs labeled A, B, and C. Those are not needed. A few years back I was looking at making a voltage regulator for my bike. Measuring from Phase A to B, B to C and C to A you should be seeing an AC voltage? Three phase so three voltages AC. On the motor you have I am not sure if they use a field winding? During my experimenting with my little project I used one of these as my 3 phase rectifier. Inexpensive and worked just fine. Connect as in the post #6 schematic or in the above video.

Ron
hi, its not my project ,but it try to learn from everyone. i was looking for a rectifier inteasd of trying to build one .he is using the one you used .it was a great help. you can buy it from here for a very cheap price https://www.aliexpress.com/item/400...pdp_ext_f={"sku_id":"10000000240892458"}.good luck
 
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