Konstantinos Laskaris: It’s well known that permanent magnet machines have the benefit of pre-excitation from the magnets, and therefore you have some efficiency benefit for that. Induction machines have perfect flux regulation and therefore you can optimize your efficiency. Both make sense for variable-speed drive single-gear transmission as the drive units of the cars.
So, as you know, our Model 3 has a permanent magnet machine now. This is because for the specification of the performance and efficiency, the permanent magnet machine better solved our cost minimization function, and it was optimal for the range and performance target.
Quantitatively, the difference is what drives the future of the machine, and it’s a tradeoff between motor cost, range and battery cost that is determining which technology will be used in the future.
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When you have a range target [for example], you can achieve it with battery size and with efficiency, so it’s in combination. When your equilibrium of cost changes, then it directly affects your motor design, so you justify efficiency in a more expensive battery. Your optimization is going to converge on a different motor, maybe a different motor technology. And that’s very interesting.
