AC motors vs BLDC non-hub

[tarunsmehta]

I was wondering that why don't we see AC motors in electric bikes and scooters? Everything I have seen (including the mass produced chinese bikes) have a BLDC hub motor and in some cases a non-frock motor.

Checked up on Kelly controllers, the cost of a AC motor controller wasn't any different from a BLDC motor. Then why don't we see them on bikes at all?

 

[Teh Stork]

With small size, AC motors have poor efficiency. This, together with the fact that production equipment of small AC motors are rare - makes them unsuitable for the ebike market.

 

[Gab]

And the opposite question, why dont we see large brushless DC motors in electric cars ? and only see DC brushed or AC induction motors ? Which is more powerful , light and efficient, brushless DC or AC ?

 

[Arlo1]

pmac bldc pmsm are the most power dense. Ebikes need power density. Induction motors can free spin using a lot less energy. So in a car where efficiency matters induction is on the list of good choices. The Volt and the leaf use PMAC motors (basicly BLDC) they don't make the power tesla does but tesla needs efficiency and their rotor is still a little bit of a secrete I know it uses copper but the process of making it on the cheep is not known.
Rimac which I think is the current most powerful electric car in the world with 1088 whp! Uses 4 250kw BLDC motors! One per wheel I think they changed the front now to a lower rating because they found 500kw to the front wheels was a waste of power and weight!

So.... BLDC or PMAC or PMSM are all used in cars and so is induction... I have a small induction motor I would love to run in a ebike it would be cool to peddle with no drag when the battery is dead.

 

[circuit]

As for small ac motor.. What about these?
http://www.ebay.com/itm/WATER-COOLED-SPINDLE-MOTOR-3KW-WELL-APPRECIATED-BY-THEIR-PURCHASERS-q1-/230949322273?pt=LH_DefaultDomain_0&hash=item35c5a6fe21
Have it on CNC - really silent..