How Do Tesla's Induction Motors Work in Their Electric Vehicles?

[Phellippe Marques]

As a EE student, I studied Induction motors: three and single phase. I saw somewhere that Tesla's autos are using induction motors feeded by batteries. But I've never heard about DC induction motors.. I also heard that Tesla autos have torque constant for every speed, but that's also not how induction motors behave. Any Ideas? Thanks!

 

[NascentOxygen]

I would assume these vehicles use electronics to convert the battery's DC to an AC that can drive the AC motors. Possibly this inverter might produce 3 phase AC, with 3 phase motors being both light and powerful.

 

[cnh1995]

I saw somewhere that Tesla's autos are using induction motors feeded by batteries. But I've never heard about DC induction motors..

There is an inverter connected to the battery which converts dc into three phase ac.

 

[Phellippe Marques]

Thats enlighting for the power supply question. How about the constant torque?

 

[Rive]

How about the constant torque?

This rate of DC-AC conversions are mostly controlled with DSPs in every detail. Phase, frequency, current (even waveform can be changed , if one has some wicked ideas) as function of thrust and speed - you can do as you please as long as the hardware can endure it.

 

[jim hardy]

How about the constant torque?

Torque-slip curve as published is for nameplate voltage and frequency.
Of course there's a family of curves, one for every voltage . At half voltage you get one quarter torque, etc.

So they adjust voltage and frequency to produce desired torque for running RPM.

Search on "field oriented control of induction motors"
eg
https://en.wikipedia.org/wiki/Vector_control_(motor)
http://www.ti.com/lit/an/sprabp8/sprabp8.pdf

 

[Phellippe Marques]

Guys, I understood both the Dc-Ac conversion process in order to feed the 3phases induction motor, and the idea of controling the parameters to keep the output torque constant. I thank you all for the attention and help. Its enough for me, for me, the topic may now be closed