Featured Nissan motor analysis Munro

does it reduce rare element usage?

 

i wonder if they are expensive motors to build. ariya is not an inexpensive car, for what you get

 

I like the rational they used, reduce the supply chain issues and make highway driving energy efficient by not needing to waste battery capacity using field weakening. As said in the video, no one really cares about town energy consumption, plenty of recharge facilities in the city, not so much out on the freeways.

T1 Terry

 

I'm not sure what field weekening is, but Tesla and Toyota both use a type of motor that changes from PM (low end torque) to reluctance (high end power) by changing the phase angle in relation to the rotor.

 

So, then, it will require replacement every three years/30,000 miles like alternators. It sounds like typical Nissan reliability. LOL

 

and not like the cabin filter on an id buzz

 

Or like a timing belt on a Chevy Trax.

 

The dual brushes are carrying very little current so the should last a reasonable time, and the cover comes off easy enough to replace the whole assembly ..... I can't see that being serious issue.

I think it will a few yrs before we see very many of these turning up at salvage auctions, so I won't hold out waiting to get one to put in my VW Kombi.

T1 Terry

 

A neighbor had a Nissan Maxima. The alternator and starter would fail every other year (like everything else in the car such as the transmission, electrical systems, etc.). He never paid for them because the auto parts stores had warranties for alternators and starters; so, he would just return the old one and get a new one. Eventually, the car became undrivable due to transmission issues, and he got rid of it.

That's why we buy Toyotas here. LOL

 

induction motors are very old. the trade off is a slight loss of efficiency and added weight versus the ability to have higher less efficient power. If rare earth magnets get whacked by the trade war again then these induction motors should be relatively less expensive.

Dual motor tesla's use one of each a permanant magnet motor in back and an induction motor up front.

 

Do you understand why they do that?

I know that the aim is to length the max torque at a given speed. Field weakening in a permanent magnet motor reduces torque and at the same time, an induction motor has less torque at low speed so requires more energy input compared to the performance output. There is a point where this swaps over between the two types of motor design.
By using the rear permanent magnet motor to provide peak torque up to the point the back EMF would limit any further rpm increase without field weakening .... at the same point, the front induction motor comes into its own and can have the magnetic field weakened by simply reducing the voltage in the stator .....

I watched a few You Tube videos that explained field weakening to make it easier to explain .... and ...... yeah, it didn't refresh the memory or make any lights turn on .... it just gave me a headache as my eyes rolled back .... can't believe I once understood all this stuff

T1 Terry

 

There is also the lack of drag from permanent magnets when the induction motor isn't being used.

 

Personally I don't see the huge advantage of having a slightly more efficient motor when there are bigger fish to fry.

A 99% efficient motor will give around 10% range than an 89% efficient motor, so a 300 mile car gets to go another 30 miles. And after that there really isn't any more to squeeze out, that's it.

But we have a bunch of energy going to rolling resistance and likely even more going to air drag, yet everything has to look like an SUV instead of being aerodynamic.

I sure hope Aptera succeeds.