SpeedStart: CPT announces second-generation start-stop system

CPT has fitted a Volvo S40 with its new 'SpeedStart' start-stop system to demonstrate its efficiency and effectiveness. The second-generation system is production-ready

Controlled Power Technologies (CPT) has developed a second-generation start-stop system, which it claims outperforms existing designs of modified starter motors and alternators. The new system – named ‘SpeedStart’ – is being shown to engineers and automotive experts this week at Europe’s largest conference for vehicle electronics, which is held every two years at Baden-Baden in Germany.

CPT’s production-ready SpeedStart system is more powerful, efficient and usable than first-generation stop-start systems. It’s the first design that integrates all the power and control electronics into a single electric motor assembly, and by maximising the number of stop-start events, the system aims to significantly reduce fuel consumption and CO2 emissions.

SpeedStart also meets manufacturer requirements for a service life of 10 years or 250,000km, which is in line with automotive industry standards for major powertrain components. With its high peak power of 3kW, the liquid cooled unit is thermally stable even with extreme under-bonnet temperatures and powerful enough to cope with petrol engines of up to 3.0-litres and diesel engines of up to 2.5-litres, thereby covering most vehicles segments.

To demonstrate the technology, CPT has installed its SpeedStart system in a Volvo S40 equipped with a 2.0-litre common-rail diesel, a size of engine which is common for European family cars yet a tough if not impossible challenge for existing stop-start systems. SpeedStart can not only cope easily with this high compression diesel engine, but also restart it in almost half the time required by a normal starter motor (0 to 750rpm in less than 0.4 seconds against typically 0.75 seconds).

Operating with up to 86% efficiency, which is significantly more efficient than even the best alternators, the SpeedStart system makes a radical departure from conventional designs by employing switched reluctance motor technology. During comparisons with permanent magnet electric motors, this alternative technology came out on top in every aspect. Significant advantages include the simple construction, accurate control and very high power density and efficiency.

‘CPT’s technical breakthrough has resulted in a state-of-the-art 12-volt system with the torque and power necessary to restart quickly, smoothly and more frequently, most modern diesel and petrol engines,’ says CPT senior manager Mike Dowsett. ‘Unlike existing systems, SpeedStart allows the vehicle to remain in gear when the engine is stopped, which is more natural for the driver and facilitates a faster restart.’

‘We’ve also successfully addressed one of the major criticisms of first-generation stop-start systems, which cause many motorists to disengage them, and that is their intrusiveness and whether they are powerful and fast enough to cope with a driver having a sudden change of mind, which is not uncommon and what often causes a motorist to lose confidence in the existing technology,’ says Dowsett.

‘What we’ve proved is that it is possible to build a highly refined system that becomes almost unnoticeable to the driver, and once that has been achieved it creates the opportunity for car makers to offer stop-start as a standard feature on all models – thereby achieving a serious reduction in CO2 emissions,’ adds Dowsett.