Soon I will move to a new house with electricity in the garage. This would make it possible to start thinking EV for commuting to work (25km/16mi single trip) since I can finally charge the vehicle overnight. Normally I use a motorcycle to commute.
Now, I have done some math, and making myself a electric motorcycle with 50km range and cruise speed of 80km/h (50mi/h) is at best expensive and bulky. Lead-acid would be way too heavy and bulky, Li-ion would be too expensive, NiMH would be too expensive too; it would be hard to operate such a bike at the same running cost as a regular motorcycle.
Another option would be a bicycle conversion. At 35km/h (22mi/h) the amount of Wh/km needed is much lower, and I could use dedicated bicycle roads (I live in The Netherlands..) which are normally closed for cars and motorcycles. Not having to dress up for the motorbike trip every time could compensate the lower top speed also.
So, currently I am redoing the math for the bicycle. Buying one is not an option; there is no fun in that, and Dutch law restricts motor power to 200W max. I am more interested in a motor with about 750W output. I once broke my leg in a traffic accident, and since then puttung a lot of force on the bicycle pedals is a problem.
When researching suitable motors for the electric motorcycle, I was inclined to use a 3-phase induction motor with 360V battery pack. Using an industrial three-phase motor for the bicycle is way overkill, but soom I realised that a car alternator would also make a nice 3-phase motor. With the rotor shorted it is basically an induction motor, with the rotor powered it behaves like a brushless DC motor, to put it very simple.
Alternators can be obtained for little money, and I am quite capable of designing and building the required inverter myself. MOSFET's are cheap, as are the Microchip dsPIC30F signal processors with motor control unit inside. Regenerative braking would also be very easy to do. Now, that sounds like a fun project!
Thus, I am looking for more information about using a +/- 50Amp car alternator as motor. What kind of efficiency can I expect, what are the useable RPM ranges, would a 50A alternator withstand the use as a motor with ~750W output, etc?
Can you guys help?