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Old 01-06-2010, 04:35 PM   #9 (permalink)
NeilBlanchard
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Commuting in electric cars, regenerative braking, and ultracapacitors

Here's an excellent video to watch, all about EV's.



Quote:
Carnegie Mellon Robotics Institute professor Illah Nourbakhsh presents the CREATE Lab project ChargeCar, a community approach to electric cars.
The lecture is part of the Sustainability and Computer Science Seminar, a forum for discussion of ways in which computer science can and will contribute to sustainability, energy, and the environment, and to foster greater consciousness, conversation, and collaboration in this area.

For more on CREATE Lab, visit: CREATE
If you have any interest in EV's at all -- you should watch this video!

What the professor (in the video) is saying is that using a supercapacitor in conjunction with the battery, you make huge gains in getting more regenerative braking, and you unload the batteries in city driving in particular. The batteries "see" as much as a 40% decrease in load.

Directly related to this is something called "split-pi" which lets you use the supercaps with batteries that run at a higher voltage.

http://en.wikipedia.org/wiki/Split-pi

Apparently, high voltage capacitors are very expensive, and unless you use low voltage batteries and drive motors (and the associated heavy cabling), the cost becomes prohibitive. So, if you can raise the voltage using the split-pi power converter -- which is 2-way, then you can use higher voltage batteries and motor, and use smaller gauge cabling, too.

Here's a video demonstration of the split-pi -- it is software controlled, and can double the DC voltage in one direction, and in the other direction, it can cut it by up to half.

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Last edited by NeilBlanchard; 01-06-2010 at 11:13 PM..
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