2 March 2011

Lotus Engineering provides electrical integration expertise for ultra luxury vehicle

Lotus Engineering, a company with over 20 years of EV and HEV experience, has been responsible for all aspects of the electric drivetrain integration for 102EX, the Rolls-Royce Phantom Experimental Electric. This includes the largest battery pack fitted to a road car, together with an innovative 7 kW induction charging system. These components and the electric drivetrain have been integrated by Lotus Engineering into the existing Phantom electrical systems, giving an efficient electrical propulsion control strategy and retaining full vehicle functionality.

Lotus Engineering has a broad expertise in vehicle design, manufacture and development. For the Phantom Experimental Electric project Lotus Engineering provided engineering services in the areas of: drivetrain layout, vehicle simulation, Computer Aided Engineering (CAE), component specification, vehicle build, control strategy, control integration, procurement, commissioning and development testing. This project highlights the technical competence in Electrical and Electronic Integration and the capability and range of consultancy services offered by Lotus Engineering.

The Phantom Experimental Electric has two electric motors to replace the 6.75 litre V12 engine. These electric motors each produce 145 kW of power to provide a total 290 kW and torque of 800 Nm giving a 0 - 100 km/h time of under eight seconds and a top speed limited to 160 km/h.

In the conversion of a Phantom into an electric vehicle a study was conducted to ensure that the optimum layout of the electric drivetrain and ancillaries was achieved with no intrusion into passenger compartment. Following an iterative design study the 71 kWh, 640 kg lithium ion battery pack was placed under the bonnet where the engine had been. The two motors, gearbox and inverters were located behind the rear seats in the original fuel tank bay, with power cables running longitudinally between the converters and the battery. This has enabled the Phantom Experimental Electric to retain its 50:50 weight distribution and characteristic Rolls-Royce driving experience.

The Rolls-Royce Phantom is a complex vehicle with many advanced electrical systems. The integration of the electric drivetrain and ancillaries with the existing vehicle control unit provided the greatest challenge for the project. To compound this the Phantom Experimental Electric features the additional complexity of a 3 mode charging system (single phase, three phase and the inductive power transfer) together with a two level driver selectable regenerative braking system.

Dr Robert Hentschel, Director of Lotus Engineering, said “The Rolls-Royce Phantom Experimental Electric is an extremely advanced vehicle. I am delighted that Rolls-Royce Motor Cars has recognised Lotus Engineering’s world class engineering capability and chosen us to be a part of this project. We have taken a great deal of pride working for such a prestigious ultra luxury brand and I believe that this project illustrates the technical competency of Lotus Engineering in Electrical and Electronic Integration and the capability to apply our expertise to a wide range of applications and types of vehicle”.