Car alternator as a motor? Hybrid Brushless Motor????
- Thread starter VoKuS
- Start date
I havne't looked at that one, but htere are threads about such conversions around ES here and there. At least one member built a fairly powerful bike around one as a middrive, IIRC, but I dont' remember any names-you'd just have to search, probably for "alternator". or "altermotor", or similar.
Jeremy Harris
100 MW
Yes, you can certainly turn an alternator into a three phase motor, either brushed (as in that article) or brushless (if you replace the rotor with one that has permanent magnets). They can be reasonably powerful, as a typical car alternator is rated at around 1 kW and so will run at the same sort of power as a motor as it would as an alternator.
There are some potential problems, though.:
- The first is that the laminations in the stator aren't usually very thin, so the core losses can be quite high if you try to spin one fast to get more power from it.
- Secondly, the windings may not be as good as they could be for the size of stator, it may be preferable to rewind the stator to get a better copper fill and higher efficiency at low speed (rpm being limited by the point above).
- Finally the rotor will use power if externally excited through the alternator brushes as suggested in that article. This will typically be around 30 to 50 watts of additional heat in the motor, and a big hit on efficiency at low power levels.
If you want to convert an alternator to a motor, then the best way to go about it is to choose an alternator that uses thin laminations (one of the Japanese makes happens to use a very nice stator core, apparently) then fit a permanent magnet rotor, removing the need for the brushes and slip rings. There are several companies that supply permanent magnet rotors for alternators, mainly for the wind power people. I'd steer clear of the rotors that use the standard skewed claw pole pieces with a ring magnet, as that's not a good configuration for a motor. A rotor that uses a standard inrunner type array of neo magnets on a core would be better.
There are some potential problems, though.:
- The first is that the laminations in the stator aren't usually very thin, so the core losses can be quite high if you try to spin one fast to get more power from it.
- Secondly, the windings may not be as good as they could be for the size of stator, it may be preferable to rewind the stator to get a better copper fill and higher efficiency at low speed (rpm being limited by the point above).
- Finally the rotor will use power if externally excited through the alternator brushes as suggested in that article. This will typically be around 30 to 50 watts of additional heat in the motor, and a big hit on efficiency at low power levels.
If you want to convert an alternator to a motor, then the best way to go about it is to choose an alternator that uses thin laminations (one of the Japanese makes happens to use a very nice stator core, apparently) then fit a permanent magnet rotor, removing the need for the brushes and slip rings. There are several companies that supply permanent magnet rotors for alternators, mainly for the wind power people. I'd steer clear of the rotors that use the standard skewed claw pole pieces with a ring magnet, as that's not a good configuration for a motor. A rotor that uses a standard inrunner type array of neo magnets on a core would be better.
Definitely.
There's a 25 page thread on this forum on the subject. I read it all because I was intrigued by the possibility. Unfortunately, it was mostly spam by someone called Randy (also known as bobdiode and other aliases) who tries to scam people into buying conversion parts.
The summary is: it can work, but you're looking at maybe 1KW output for something that weighs 15lb.
There's a 25 page thread on this forum on the subject. I read it all because I was intrigued by the possibility. Unfortunately, it was mostly spam by someone called Randy (also known as bobdiode and other aliases) who tries to scam people into buying conversion parts.
The summary is: it can work, but you're looking at maybe 1KW output for something that weighs 15lb.
Jeremy Harris
100 MW
Punx0r said:
As you've worked out, you can pretty much ignore anything Randy/Bobdiode contributed as being close to total BS. The shame was that he had useful contacts and could get hold of some interesting stuff, yet this was made useless for the rest of us because of the large BS factor and hi complete failure to even attempt to accept the known laws of physics.
