3 ms·
> except that it is not clear if the energy efficiency can be equally good. There are potentially ways energy efficiency can be better... It's possible to pro
by londons_explore 3y ago
> except that it is not clear if the energy efficiency can be equally good.
There are potentially ways energy efficiency can be better...
It's possible to produce stronger (ie. more flux density) magnetic fields with electrical currents than with neodymium magnets. Those stronger fields mean flux paths can be shortened and (for the same mass of copper), wires can be shortened and resistive losses reduced.
However, I haven't done the math to see if those effects are of a significant enough magnitude.
- effie 3y agoI don't see it. In a brushless DC magnet rotor, there is little energy loss, the magnets aren't very conductive. Here, we have additional current and newly introduced Joule losses in the rotor. It is not clear that these can be kept low enough so the result is as good. Stronger magnetic field due to high current in the rotor does not directly imply higher efficiency, it only directly implies higher torque, which gives the car higher acceleration. We don't need to increase this strength, current motors are plenty strong. This top torque mode of operation usually goes with decreased efficiency, due to high currents and high Joule losses. The best efficiency is likely to be achieved when ohmic and friction losses are kept low, thus currents as low as possible everywhere, induction coupling frequency dynamically governed to be at the optimal value dependent on the angular speed. The only obvious advantage of the marketed motor is smaller size and likely lower weight. I'm afraid price will be a disadvantage.