Electric Tow Vehicle (Tesla)

Turtle n Peeps wrote:

Procrastinator wrote:
We know that locomotives use diesels to power a generator to power the electric motor. We also know that each diesel engine has a sweet spot for power and fuel economy. Why could we not have a truck that "idles at 1800 rpm" running to power the generator for the electric drive motor. Forget batteries. We would have the electrical motors max torque from rpm 1. I personally want the economy of a diesel with the instant torque of an electric motor. Now if it looked like that....maybe not.

You could. Problem is you lose energy every time you switch from one to another......A LOT of ENERGY.

Ever touch an electric motor after working hard? There goes 20 to 25% of your hard earned diesel up in heat........on top of the diesel you lost to create it.

Turtle is right. For the time being.

In the past I predicted that it would make more sense to use straight electric transmissions instead of the very pricy, newer hydraulic/electric control morphodites we have now. I based my opinion on the high relative fuel efficiency of towing locomotives and the fact that the astounding Toyota Prius uses it too. Neither has a gear switching arrangement or hydraulic torque converter. They both have final drive gears though.

But since then I've realised that Turtle is right. The tried-and-true hydraulic and/or manual gear propulsion is presently less lossy in terms of wasted energy (heat energy). The locomotives have huge blowers directing air through the axle-mounted traction motors, and I believe the Prius gen-motor sets are oil bath cooled.

However, there is a special condition where generators, or motors, are highly efficient, more efficient than gears or hydraulics. That is in the case the windings are super-cooled, whereas the static electrical resistance is practically zero. In these cases, the unimpeded current produces copius magnetism nearly indefinately once electrons began to circulate the frigid zero-resistant wires; without continued application of significant new power. The practical use of such fantastic physics apparently is not as far-fetched as one might think, since considerable experimentation has been done in providing continuous super-cooled magnetic levitation for high speed commuter trains using super-cold liquified gas baths. This phenomena could also be used to run very efficient "vacuum bottled" electric generator/motors since they would waste little, or no, heat energy during their electric coupling.

The reasoning that the locomotives originally used electric transmission is as Procrastinator said, the ideal torque conversion that occurs from a dead stop. Whereas the internal combustion engine has a sweet spot somewhere well above zero rpm, the electric drive provides maximum torque from stall speed and tapers off on up. The Prius, or an electric truck, has this continuously variable transmission(CVT) advantage along with the fact that power may be provided either by a battery, or generator. The anemic Prius engine therefore runs in a very narrow, efficient rpm band.

Wes
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