Some more pictures:



Well, I bought it just because it was cheap (unfortunately I promised the seller not to give the number, but I payed much less than EVTV did).WOW!
What's you plan? What vehicle are you going to put it into?
It makes my latest acquisition, Beryl the EV, look a bit, ummm, rustic!![]()
Thanks! I don't have an exact figure, but I would place this somewhere around 140kg (motor+inverter+gearbox). The power per kg ratio in Tesla is amazing.Great work,this is my first look.
Do you have a weight on the package?
Great, I'm glad there are people seriously looking into the design of that motor as wellGreat photos, thanks for sharing. Looks like you have a fun project.
Would you be able to measure the resistance and inductance at the motor lugs, phase to phase? Maybe at DC, 60 or 120 Hz, 400 Hz, 1000 Hz?
Why is this important or of any interest? Because these electrical characteristics are used in the calculations made by the inverter to drive the motor using a Direct Torque Control (DTC) scheme, described in TM patents.
For a 3-phase, 4-pole wye motor with the poles wired 2s2p, and with 4 Turns per pole using 16 AWG copper wire 12-in-hand, i've done a rough calculation:
phase inductance ~ 493 nH
phase resistance ~ 5.3 mR
This gives an L/R time constant of 93 usec. If we use 3 tc to reach full current, then the inverter would need to generate a current waveform at about 895 Hz and the motor max speed ~ 26,858 rpm. With a 9.7:1 gearbox the theoretical max speed would be ~228 mph, but realistically the available motor power at that rpm wouldn't be enough to propel the car that fast.
There seems to be an encoder mounted on the side of the motor - not a resolver or anything like that. I still have to look into that section of the control, but there are no resolver digitizers onboard, so it is safe to presume Tesla is using standard optical/magnetic encoders.Great stuff!
Encoder or no encoder?
Great catch in finding the phase current sensor and the explanation.There seems to be an encoder mounted on the side of the motor - not a resolver or anything like that. I still have to look into that section of the control, but there are no resolver digitizers onboard, so it is safe to presume Tesla is using standard optical/magnetic encoders.
kennybobby, the Direct Torque Control actually sounds about right, as I found very hardcore phase current measurement system in the inverter. Every other manufacturer uses hall effect sensors to measure the phase current (two or three), but Tesla designed a bus bar that has a small section made from less pure / more resistive material, and soldered a voltage drop sensor on top of it.
...
This is what gave me the impression that there is indeed an encoder (looking on the motor side). Next time I see my motor, I'll track the wires and check where it goes and if it can be an encoder. My bet is on magnetic sensor like for the ABS system.didn't see anything that looked like an encoder on the motor pictures, but you're the only person to split one open and can answer that question--we are dying to know...
That's pretty good for an induction machine. Can't quite compete with a good PMAC system, but impressive nonetheless.Thanks! I don't have an exact figure, but I would place this somewhere around 140kg (motor+inverter+gearbox). The power per kg ratio in Tesla is amazing.