[Crossy]

Hi All,

I am new to the forum and would like to ask a question that has been probably asked numerous times.
When I search the forum I get a bit lost searching for the answer..

Basically I have 3 general questions:
1-What is the main build difference in an industrial motor and an EV motor? are the winding different? are the rotors different? or is there any 1 characteristic that EV motors have and industrial motors dont? (P.S. I am referring to AC induction motor)
2-How can a 200kw EV motor be so small and a 200kw industrial motor be larger than the car? I understand the industrial motor is designed to run at 200kw under constant load and the EV motor is only peak for a few seconds at 200kw but is that the only reason it can be way smaller?
3- In theory what would happen the 200kw EV motor if we kept it under full load for a long duration like an industrial motor ? example pulling a trailer that was way too heavy for the car? Would it overheat? If so is it in theory not even close to a constant 200kw motor?

Sorry for the annoying questions but I just cant find enough details on it online. Only many companies willing to sell me the whole package and keep it a secret.
I am just finished a degree in Mechatronic Engineering and currently build high power gasoline track cars in my spare time. I want to try build a crazy fast electric car now. The electronic controls and wiring is simple enough to me but I just wanted to have a greater understanding of motor design before I jump into it.

Thanks for the help

 

[mayes8229]

Continuous ratings vs peak ratings are a significant factor, so I think you're correct in that conclusion. Another reason is the power curve. A 200kW EV motor is making that power with a lower torque number and a higher RPM, while a 200kW industrial motor is (in most cases) going to be making that power with a larger torque number and a lower RPM. You can spin a small motor really fast to make power or spin a big motor slower. That's why a lot of EV motors are spinning around 10,000RPM or more at highway speeds with a lot of gear reduction.

As far as continuous loads are concerned, it's all dependent on cooling capacity. If you can keep the motor, controller/inverter, and batteries cool you can run it at peak power as long as you want. That's much easier said than done however.

 

[Duncan]

I agree with mayes8229 -
The motor weight is (very roughly) proportional to the amount of TORQUE that it can produce
So a Tesla has a 35 kg motor and a 10:1 reduction gearbox to produce the torque that would require a 350 kg motor

On top of that is the time rating - my DC forklift motor is 102 kg - and is rated at 10kw for one hour - it survives 400kw on the track