Electric turbo ready for production. image

At a high level international automotive conference in Stuttgart this week Controlled Power Technologies will present the benefits of an innovative electric supercharging system developed for the smaller more fuel-efficient engines being progressively introduced by carmakers to reduce vehicle CO2 emissions.

CPT’s Variable Torque Enhancement System (VTES), which utilises ‘switched reluctance’ technology, is ready for high volume production and can be applied cost-effectively to all types of gasoline and diesel engines including those already turbocharged.

For diesel engines, a near instant air supply enables delivery of high transient torque with minimal particulate emissions, offering potential for significant diesel particulate filter (DPF) downsizing. The technology also provides potential for energy recovery during throttled operation on gasoline engines and can provide the air supply for future fuel cell electric vehicles currently under development by the motor industry.

Guy Morris, engineering director and chief technical officer, will present CPT’s new technology to an expert audience attending the Advanced Charging & Downsizing Concepts Congress being held at Steigenberger Graf Zeppelin in Stuttgart, Germany. The three-day international assembly of automotive engineers takes place on Monday 31 March through to Wednesday 2 April 2008.

From an idea first conceived in the year 2000 this technology has been progressively developed to the point where it is now a mature well-proven second-generation design, ready to be adopted by carmakers,” said Morris. “Uniquely the supercharger utilises a switched reluctance motor – a technology that is well-proven in other industry sectors but has yet to be applied by the automotive industry.

From the outset this new-type of electric motor – applied in this instance as a supercharger with other applications to follow – has been developed with the close involvement of carmakers in order to meet stringent automotive industry standards and vehicle manufacturer requirements.

Seven years on and we’ve reached the final stage of product development and production readiness,” says Morris. “The system offers a high level of vehicle performance because of the significant torque enhancement it delivers at low engine speeds. The switched reluctance motor, which operates using existing 12-volt electrical systems, is both highly efficient and responsive.

Carmakers are especially attracted to the low level of engineering effort when applying the technology and in particular the minimal production investment required. It’s a small compact system with fully integrated electronics that’s easy to install – it’s virtually plug and play.

“For the motorist it simply means having the economy of a small engine with the performance of a big engine. For example, in a high gear there is typically a 40 per cent reduction in 70-100kph (45-65mph) acceleration times. This is worth around seven seconds in a 1.2-litre car with a six-speed gearbox.

“When optimised, VTES can dramatically increase the engine air charge density over the first 10 combustion cycles of a low speed transient operation, hence enabling real improvements in both torque and emissions performance, where it matters most.

“Looking ahead, this technology also has the potential for energy recovery during throttled operation of gasoline engines. The motor can switch to generator mode almost instantly, the compressor can be configured as a ‘cold air’ induction turbine with efficiencies of more than 50 per cent being possible, while power levels greater than 150W can be readily generated at 14 volts.

“For fuel cell applications we’re looking at a 2-stage high voltage (240+ volts) concept delivering approximately 4kW of stabilised power offering a more compact, lower mass and lower noise system than other solutions.”

Controlled Power Technologies was created a year ago as a management buy-in funded by venture capital and recently completed the acquisition of its portfolio of production-ready solutions to the problem of automotive CO2 reduction. The company comes with the backing of a highly experienced team of automotive engineers and is funded by a number of prominent investors specialising in the energy and environmental sectors.

In addition to its production ready electric supercharger, CPT’s family of low carbon powertrain related products includes an application ready stop-start system now moving close to production readiness, and an exhaust energy recovery system in an advanced stage of development.

The originality in all the products is that they utilise highly efficient ‘switched reluctance’ electric motors; an as yet untapped technology for the automotive sector, but widely used in many other industry sectors for their robustness and reliability.

“Switched reluctance motors are well suited to the requirements of the automotive industry,” says Morris. “They can be produced for high volume series production at very low cost; they are manufactured mostly from easy-to-recycle steel and aluminium and avoid the use of exotic, expensive and heat sensitive materials. These compact motors are easy to package and offer excellent energy efficiency and controllability.”

Controlled Power Technologies has secured an exclusive license from Switched Reluctance Drives Limited to develop its unique electric motor technology for the automotive sector. SR Drives is a UK company based in Harrogate and wholly owned subsidiary of Emerson Electric Company. A major multinational corporation headquartered in St Louis, Missouri, USA, Emerson is a Fortune 500 company providing engineering services and innovative solutions for customers in a wide range of industrial, commercial and consumer markets and is one of the largest engineering and conglomerate companies in the world.