31–39 of 39 posts
If we created demand for Thorium, we could solve the energy and rare-earth problems with one blow. There is a kind of rare earth ore that we could mine profitably, if there was only something to do with the Thorium. http://www.forbes.com/sites/energysource/2011/03/28/rare-ear...
If we created demand for Thorium, we could solve the energy and rare-earth problems with one blow. There is a kind of rare earth ore that we could mine profitably, if there was only something to do with the Thorium. http://www.forbes.com/sites/energysource/2011/03/28/rare-ear...
Thorium power is interesting, but in no way is it a substitute for other rare-earths.
I went to the trouble of learning this just now, so I might as well share: The most basic electric motor is to have two electromagnets which can rotate with respect to each other. You can make one fixed, but the other has to rotate while still being powered . This requires an electrical connection for a spinning part, and the easiest way was "brushes", apparently. These are literally just metal wires with some spring…
And then there is the option mentioned in the article, where the spinning permanent magnet is not made of expensive rare-earth metals, but rather of a metal in which a magnetic field is induced by stationary windings.
Earlier quoted context omitted.
Simplicity and reliability. The rotor is completely inert (no windings). The big drawback has historically been "torque ripple". However, with modern high-speed power electronics, the current to the windings can be modulated to counteract this. Full torque at 0 RPM. An SR machine combined with efficient backlash-free reducing gearing (torque amplification) may be able to deliver the reliability and torque density to…
Thank you very much. Exactly what I wanted to know. But, just a doubt, even Induction motors offer full torque at 0 RPM, right? Please correct me if I'm wrong, because that's what a reviewer said while comparing a BMW and the Tesla Model S. Thanks!
But modern control systems (which, I might add, are still much simpler than those for switched reluctance motors) can achieve full torque from a standstill (basically by bringing the synchronous speed to near zero).
Squirrel Cage Induction Motors have been around for years and have been used in Industry forever. No brushes, no magnets... http://en.wikipedia.org/wiki/Squirrel-cage_rotor
Squirrel Cage Induction Motors have been around for years and have been used in Industry forever. No brushes, no magnets... http://en.wikipedia.org/wiki/Squirrel-cage_rotor
And jack all low end torque, something very important to car applications. http://en.wikipedia.org/wiki/File:Variation-couple-uf.svg
Induction motors have long been in existence and they achieve the same goals too. In fact, many popular automotive companies still use Induction motors in their cars (Eg.Tesla). What makes these switch reluctance motors attractive over the induction motors , then? Could someone please clarify?? Thanks.
IIRC, Induction motors are great, but they have one major fault, without some complex circuitry, they can't be instantly switched on/off. Although a polyphase induction motor should not have that problem.
Earlier quoted context omitted.
Thank you very much. Exactly what I wanted to know. But, just a doubt, even Induction motors offer full torque at 0 RPM, right? Please correct me if I'm wrong, because that's what a reviewer said while comparing a BMW and the Tesla Model S. Thanks!
Depending on the control system, yes. If you run an induction motor off a fixed-frequency supply, it produces very little torque until it is spinning near it's synchronous speed (typically 3600 RPM, but depends on the supply frequency and pole multiplicity). That's why, for example, bench grinders can take forever to come up to speed. But modern control systems (which, I might add, are still much simpler than those f…
