Electric Mini: 0-60 in 4 Seconds: It Has Motors In Its Wheels

From TreeHugger
August 30, 2006

A British engineering firm has put together a high-performance hybrid version of BMW's Mini Cooper. The PML Mini QED has a top speed of 150 mph, a 0-60 mph time of 4.5 seconds. The car uses a small gasoline engine with four 160 horsepower electric motors — one on each wheel. The car has been designed to run for four hours of combined urban/extra urban driving, powered only by a battery and bank of ultra capacitors. The QED supports an all-electric range of 200-250 miles and has a total range of about 932 miles (1,500 km). For longer journeys at higher speeds, a small conventional internal combustion engine (ICE) is used to re-charge the battery. In this hybrid mode, fuel economies of up to 80mpg can be achieved.

Explains Martin Boughtwood, PML’s MD: “Until now, most electric vehicles have been little more than souped-up milk floats, limited by range and speed, with compromised performance. For those with a green conscience who also value an enhanced motoring experience, there is still something missing.

“Working in partnership with our customer, Synergy Innovations, we set out to demonstrate what our electric wheel technology is capable of. We simply took a standard BMW Mini One, discarded the engine, the disc brakes, the wheels, and the gearbox. These components were replaced by four of our electric wheels, a lithium polymer battery, a large ultra capacitor, a very small ICE with generator (so small it almost fits alongside the spare wheel), an energy management system and a sexy in-car display module.”

The benefits of PML in-wheel drive technology are;

* It is adaptable to other vehicle chassis
* It eliminates the need for gearing and mechanical drive train
* It allows more space inside the car

The vehicle has three driver-selectable modes of operation:

* Eco mode for town/city frequent start-stop driving;
* Normal mode for daily commuting and ICE- equivalent operation, and
* Sport mode for super car performance.

Other notable features include:

* No (mechanical) brakes means returned energy!

All braking is performed by the wheel motors acting as very efficient electrical generators which return almost all of the energy back to the battery system. The beauty of this dual-circuit, ultra safe system is that your green conscience can be quite content even when accelerating hard, since you are assured of collecting most of the expended energy when it is time to slow down rapidly.
ABS as standard – even when accelerating

Because the wheels are high performance motors, ABS comes as a standard function built into each wheel’s software. Now anti-skid can also be applied to acceleration since the motor can smoothly control torque delivery to/from the road in both cases. Flooring the brake or accelerator hard merely results in controlled maximum torque, giving the shortest possible stopping or acceleration time.
Clever wheels

The technology eliminates the need for crude differential gears to share power between left and right sides. The wheels are in constant communication with each other deciding 1000 times each second how much torque share is optimum for the current driving conditions. Should one wheel detect a slippery surface and take appropriate anti-skid actions, the other wheels are aware of this instantly and adopt an appropriate compensating strategy to keep the vehicle as stable as possible.
640 brake horsepower – for life!

Each wheel develops 160bhp - 640bhp in total. The original Mini One develops less than 100bhp with an engine that weighs nearly double the weight of the four electric wheels! Apart from wheel bearings there are no wearing parts in the electric wheels; this means the horsepower stays for the life of the vehicle - and beyond.

As the battery level reduces, the rear mounted ICE/generator starts to automatically top up the battery. So when you arrive at your destination you can simply park the vehicle knowing that when you return the battery will be replenished. Alternatively you can take advantage of lower cost mains electricity and plug in to recharge. So you never need to worry about battery capacity or how to recharge. During operation, as the battery level falls the generator cuts in, enabling an average speed of 60 – 70mph to be sustained with no further battery depletion.

See more information at World Car Fans

Home page for the car: PML Mini QED