As a pioneer in the development of switched-reluctance machines for 48V mild hybrid vehicles, Controlled Power Technologies (CPT) will showcase four key applications of its technology at the Aachen Colloquium this week – represented by its Cobra electric compressor, SpeedStart belt-integrated starter-generator, SpeedTorq drivetrain motor-generator, and TIGERS exhaust energy recovery system. Two of the technologies feature in the ADEPT (advanced diesel-electric powertrain) demonstrator vehicle (in which programme CPT was a consortium partner), which makes its first appearance in Germany following its debut at the recent Cenex Low Carbon Vehicle event in the UK.

“The need for robust, refined and highly controllable motor-generators at a high level of commercial readiness has never been more evident as the automotive industry hastens the introduction of electric vehicles,” says CPT’s chief executive Nick Pascoe. “The majority of next-generation vehicles will be a new breed of 48V mild hybrids, supported by a modest and weight saving 1-2kWh battery pack, providing carmakers and other vehicle OEMs with an affordable and cost-effective route to low carbon emissions. The technology, can also contribute to improved air quality without reducing the performance of the baseline vehicle.”

“Switched-reluctance machines offer consistent high power and high efficiency over a wide speed range; unlike permanent magnet motors electromagnetic field weakening is not an issue; and the precise torque control enables a swift response within fractions of a second to changes of load on the machine. In essence, it’s a highly controllable electrical machine that can switch back and forth very quickly from motoring to generating.”

Comparable to Formula 1 technology, but at much lower and safer voltages, CPT’s switched-reluctance motor-generator units can be applied throughout the powertrain for torque assist and kinetic energy recovery, as well as recovering energy from exhaust gases. Not only applicable as original equipment in cars, the technology is also being trialled in trucks and buses and off-highway vehicles.

For CPT, 48V electrification is about efficiently harvesting and recycling kinetic and thermal energy. This is demonstrated in the ADEPT vehicle by its SpeedStart motor-generator unit, which replaces the conventional alternator and starter-motor, and helps to boost vehicle performance and fuel economy, while reducing NOx and particulate emissions. Simultaneously, CPT’s turbine integrated exhaust gas energy recovery system known as TIGERS, which integrates a turbine with a generator unit (and is quite separate from a turbocharger), simultaneously recovers thermal energy.

The potential cost of production implementation of ADEPT technology has been verified independently by Ricardo to be in the region of €60 per gram/km of CO2 reduction.  This confirms previous assessments by CPT that the additional cost to introduce 48V mild hybrid electrification is less than one-third of the additional cost of full hybrids, and one-seventh the additional cost of pure battery electric vehicles.

Other CPT machines on display at the Aachen Colloquium include its SpeedTorq motor-generator unit, which can be applied further along the drivetrain. SpeedTorq is a 20,000 rpm SRM, but unlike the engine cranking belt-integrated SpeedStart unit, the SpeedTorq unit has the ‘four-quadrant’ contra-rotational functionality essential for integration with a gearbox or axle, requiring the machine to provide its motoring and generating capability in both forward and reverse rotations.

Computer simulations based on the company’s LC Super Hybrid technology demonstrator programme indicate an impressive 26 per cent improvement in fuel economy for a large family saloon when the rear axle is also boosted with low voltage electrical power.

“Installing SpeedTorq in a rear-axle unit results in additional efficiency benefits by avoiding the parasitic losses that occur when applying torque assist to a combustion engine and transmission,” says Pascoe. “In a dual SRM application, SpeedStart, is focused on providing an extended start-stop capability, while both units are used for energy recuperation.”

Also on display at Aachen is CPT’s Cobra unit – a 70,000 rpm high speed motor for electric supercharger applications, which shares the same platform and core SRM architecture as the Tigers high speed high temperature tolerant generator for the recovery of thermal and kinetic energy from fast flowing exhaust gases.

Delegates attending the congress will be able to drive the ADEPT demonstrator on the nearby IKA test track. Further information on CPT is available at Further information on the Aachen Colloquium is available at The congress runs from the 10-12 October.

Media contacts:

CPT: Rob Palmer
+44 (0) 1582 763255 / +44 (0)7768 242761

Aachen Colloquium: Sandra Jaksch
+49 241 80 48021

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