Phantom EE expected to reach 100kph in less than eight seconds and will have a top speed of 160kph.
September 13, 2011
by Canadian Manufacturing Daily Staff
FRANKFURT, Germany—In yet another sign that car manufacturers are trying to go green, Rolls-Royce is experimenting with an electric vehicle.
The mega-luxury brand kicked off a presentation by parent company BMW AG at the Frankfurt auto show trumpeting its 102EX vehicle that features an electric power train engine based on its Phantom design.
Phantom EE features the same spaceframe as its petrol-powered bretheron, but its 6.75-litre 12-cylindre gas engine and 6-speed transmission have been replaced by a lithium ion battery back and two electric motors mounted on the rear sub-frame. The electric motors are connected to a single speed transmission with an integrated differential.
The EE is expected to reach 100kph in less than eight seconds, only 2 seconds slower than its standard Phantom and will have a top speed of 160kph.
Each motor is power rated to 145 kilowatts, giving Phantom EE a maximum power output of 290 kilowatts and torque of 800Nm. This compares with 338 kilowatts for its standard Phantom with maximum torque of 720Nm, delivered at 3,500rpm.
The nickel cobalt manganese battery chemistry holds around 230Wh/kg, a high energy density necessary to achieve acceptable range between re-charges. Pre-launch tests suggest Phantom EE should run to a range of up to 200km.
Three separate charger units (3 kilowatts each) are fitted to the battery to allow both single-phase (20 hours) or three-phase charging (8 hours), a process unique for a passenger car.
It will also serve as the proving ground for induction charging technology—a charger unit that enables wireless charging.
Induction charging uses a transfer pad on the ground that delivers power from a main source and an induction pad under the car’s battery pack. Power frequencies are magnetically coupled along these power transfer pads.
The system is around 90 percent efficient when measured from mains supply to battery and is tolerant to parking misalignment up to 150mm.
Coupling circuits are tuned through the addition of compensation capacitors. Pick-up coils in the receiver pad are magnetically coupled to the primary coil. Power transfer is achieved by tuning the pick-up coil to the operating frequency of the primary coil with a series or parallel capacitor.
The Phantom EE’s exteriour finish has 16 coats of reflective paint containing ceramic nano particles that mimics the impression of a silver metal, giving a wet impression on the car, which weighs in at more than 3,000 kilograms on a wheelbase of 3570mm.