The hybrid drive system being used by Porsche in its new 911 GT3 R isn't what you find in your average Prius or Fusion. Instead of a battery for energy storage, the 911 will use an electro-mechanical flywheel. The system being used was actually developed by the Williams formula one team and its Williams Hybrid Power subsidiary.
The system is comprised of an electrically driven flywheel and a motor/generator on the gearbox. During braking the gearbox mounted generator drives the flywheel to spin it up to 40,000 rpm. When needed for extra acceleration, the flywheel drives its integrated motor/generator to spin provide power back to the unit on the gearbox.
In the case of the 911, a pair motor generators are actually on the front wheels instead of the single unit on the gearbox as it was on the Williams F1 car last year. This provides more regenerative braking capability as well as all wheel drive.
The flywheel itself is made of a composite material that is infused with magnetic particles when it is being molded. This actually acts as the permanent magnet for the motor, helping to keep the overall weight down. The result is a very efficient system with less mass than a battery system and the ability to absorb energy more rapidly than a battery similar to an ultracapaitor. Like ultracapacitors the downside for automotive applications is limited energy storage capacity.
As a result, electric driving is limited meaning that this really behaves more like a mild hybrid system than a strong hybrid. However, the power output is closer to what is available from most strong hybrids. Williams Hybrid Power is working with a number of automakers on implementing its flywheel system although only Porsche has been publicly identified. Porsche's has setup a microsite for its new Hybrid racecar, and for more details, make the jump for the release and a video explaining the system, along with two promo videos.
[Source: Williams Hybrid Power]
WILLIAMS HYBRID POWER CONTRACTS WITH PORSCHE AG FOR 911 GT3 R HYBRID
Oxford, UK, February 11, 2010. Williams Hybrid Power Limited is pleased to confirm that the energy storage system as part of the new Porsche 911 GT3 R Hybrid, which was announced today by Dr. Ing. h.c. F. Porsche AG, Stuttgart, has been developed and supplied by Williams Hybrid Power. The 911 GT3 R Hybrid with innovative hybrid drive will make its debut at the Geneva Motor Show. Further details from Porsche follow in the attached press release.
The energy storage system was originally developed for use in Formula One by the AT&T Williams team but Williams Hybrid Power is now focused on applications in road vehicles. The technology will also be developed for larger, infrastructure applications by Williams F1 at its new research facility in the Qatar Science and Technology Park.
Ian Foley, Managing Director of Williams Hybrid Power said, "We are delighted to see our technology being adopted by one of the world's leading engineering companies and most prestigious automotive manufacturers in one of their racing cars. Partnering with Porsche on this project has been a very positive experience and we are grateful to them for choosing to work with us."
Alex Burns, Chairman of Williams Hybrid Power and Chief Operating Officer of Williams F1 said, "This is a milestone for both Williams Hybrid Power and Williams F1. Together we have worked to bring this technology forward to the point where it can be tested in a racing car and deployed in a road car. We hope that this will be just the start of the evolution of hybrid systems developed for Formula One moving across to applications where they can contribute to cleaner and more powerful vehicles."