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Old 11-27-2009, 12:23 AM   #86 (permalink)
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Originally Posted by mrbigh View Post
That's a lot of weight in batteries....
You better change continent suppliers
Use a boost converter. (Note that the 2010 Prius has a motor voltage of up to 650v but the battery is only 200v.) As for where you would get an inductor for that much current, EV girl to the rescue again!
high current inductors from copper tubing? - diyAudio
One problem is that most industrial motors operate at 208-230v minimum (for rated power), which translates into 300-325v plus overhead of DC. Not exactly practical for a battery pack. But to step up a 180v battery to 400v with a maximum load current of 200A (translates into about 100HP) at an operating frequency of 15kHz only requires about 16.5uH. That is practical for a copper tubing inductor cooled with oil. One major problem is that the metal of the car would act as a shorted turn. However, hypermilers often add "Kammbacks" to their cars. If the Kammback is made from a nonconductive material, the inductor can be installed inside it in such a way that the metal would be far away enough to not cause problems. I'm not sure about heat dissipation of 1/4" tubing when conducting 200A, but I would not expect it to be a problem as the load would usually be much less, maybe as low as 15A when cruising.
And I realized that since it would need to be a bidirectional converter in order to be able to regen, there would be no need for a separate charger buck converter. Simply rectify mains voltage (using a voltage doubler for 120v) to the boosted rail and run the converter as a buck converter to charge the batteries. In a DIY EV where cost is a major concern, it can be very helpful for saving cost.
If America manages to eliminate obesity, we would save as much fuel as if every American were to stop driving for three days every year. To be slender like Tiffany Yep is to be a real hypermiler...

Allie Moore and I have a combined carbon footprint much smaller than that of one average American...
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