GM Working on Feasible Electric Car

WindBourne writes "While Ford wants to simply offer cosmetic changes to automobiles interiors and exteriors, General Motors has finally gotten the message about electric autos. They are about to introduce the Chevy Volt, a plug-in hybrid which gets 40 Miles on a charge, but has a generator that can keep the auto going up to 640 miles range. From a styling POV, it is not a tesla, but it is also not a focus or a pinto. From the Rocky article: 'GM did not release cost estimates but said they recognize the Volt's price will have to be competitive. Company Vice Chairman Robert Lutz said in a statement that more than half of Americans live less than 20 miles from their workplace and could go to work and back on a single charge.'"

Comments

The future is AC, not DC

[kurt555gs]

I have been looking at several articles to see if GM followed the modern path of AC motors ala Toyota, and not the obsolete cumbersome DC motors of the past. ( Yes this includes computer controlled brushless DC systems ).

Toyota and ABB of Sweden really have taken the first step in the future of transportation making a 500 volt integrated Variable Frequency Drive ( VFD ) to an AC drive motor.

This 1st step was really only scratching the surface and in the future you will see 400hz and above AC motors where the VFD's DC bus is excited by batteries.

Tesla experimented with many frequencies and found 60hz right for the 1890's bearings and engineering technologies.

Jet aircraft starter motors are usually 400hz AC multi pole motors. These are very light and have tremendous torque.

As computer controls become faster in processing speed, and the IGBT transistors can be switched faster VFD's and AC motors of 400, 600, 1200hz will bring more power and lower weight than ever imagined.

The limiting factor is the processing speed of the VFD cpu's in order to do sensor less torque vector calculations, then fire off the IGBT transistors.

I hope that one of the major VFD makers will have some engineer playing games on a CELL based console and have the brilliant idea that this would solve the intense calculation requirements needed.

If Toshiba ( major VFD maker ) and Nintendo ever merge, this will be the beginning of the electric era and the sunset of the internal combustion time on earth.

Think of the possibilities.

Cheers

Re:Don't be silly

[dal20402]

Actually, stop and go is the best case for hybrids. Reciprocating engines are most efficient when they can be designed to work at fixed rpm. Starting from a stop in your car or diesel truck is very inefficient. It is much more efficient to use an electric motor for the initial start. Electric motors make max torque at 0 rpm and love low-speed operation.

When I drove transit in Seattle, I was lucky enough to drive their new New Flyer diesel-electric hybrid articulated buses. Because the big diesel didn't have to yank the bus away from a start, the buses were more fuel-efficient and much, much quieter. The lack of transmission made them unbelievably smooth. They were also the quickest transit buses I've ever driven despite being heavy 60-footers. The dynamic brakes made for a low-effort brake pedal, very smooth stops, and almost no brake wear. A full hybrid powertrain, while expensive, is absolutely ideal for urban transit buses -- which see more stop-and-go operation than any other vehicles. Fast, quiet, smooth, and fuel-efficient.

Re:The thing to watch:hybrid full size truck platf

[kimvette]

and having parts spinning around a thousand times per second in your car may prove to be a safety issue

Not really. They are very lightweight, and therefore will have little inertia. Turbochargers spin between 60,000rpm and 100,000RPM and have a strong, long, proven track record (102 years) and the only time they become unreliable is when there is a lack of lubrication, usually from piss-poor maintenance (e.g., an owner gets an oil change once every 100,000 miles whether it's needed or not), or from running the car at FULL boost, then immediately shutting down (e.g., your average teenager pulling into a mall parking lot), without letting it idle down and cool off.

Turbine generators will be far less prone to the latter. There is no cure for poor maintenance, except that the turbine housings will be strong enough to protect against shattering during a catastrophic failure. Heck, even most turbines on jet aircraft are built to contain their massive, extremely high-speed turbines, and ditto for power plants with their even more massive gas turbine engines which are run at full speed at nearly 100% duty cycle.

And waste heat? They may run at a hotter temperature, but they use far less fuel than a conventional engine. There will probably less total heat output. The fix to lower the temperature of the exhaust? Mix the exhaust with ambient air (like the stealth bombers do to reduce their heat signatures), or reclaim the heat for other purposes, such as thermocouples or sterling engines to further increase efficiency, or during cold weather, heat exchangers for heating the vehicle, rather than relying on electric coils for heat.