Valeo’s second generation Stop-Start system will be launched by PSA Peugeot Citroën in the third quarter of 2010. The system, coupled with the HDi diesel engines of the Peugeot and Citroën brands, will be featured on both manual and automated manual transmission models and will equip a million vehicles by 2013.
Valeo’s first generation of alternator-based stop-start systems (StARS) has been in serial production with Citroën since 2004, on smart cars since 2007 and on Mercedes-Benz A- and B-class vehicles as of the first quarter of 2009. This new generation micro-hybrid system, i-StARS, differs from the previous generation in that the power and control electronics are integrated into the electrical machine, thereby reducing the size of the packaging.
As Valeo had no in-house microelectronics capacity, it decided to set up a EUREKA project with two microelectronics partners: ON Semiconductors—formerly AMI Semiconductors—in Belgium for the two application-specific integrated circuits (ASICs) controlling and driving the system; and Freescale in France for the power-switching transistors. Valeo itself took the responsibility for the assembly of the mechatronics unit.
(EUREKA is an intergovernmental network launched in 1985 to support market-oriented R&D and innovation projects by industry, research centers and universities across all technological sectors. It is composed of 39 members, including the European Community.)
The micro-hybrid system automatically cuts off the vehicle’s engine at a red light or in a traffic jam and restarts it when engine power is solicited. CO2 emissions are reduced by 5g per kilometer on average, and by up to 15% in congested urban traffic.
To optimize fuel savings and make driving in the Stop-Start mode smoother, i-StARS can cut off the engine even before the vehicle comes to a complete stop—i.e., as soon as the vehicle’s speed falls below 8 km/h (5 mph) with an automated transmission and 20 km/h (12 mph) with a manual transmission.
Engine re-start is immediate (400 msec), noiseless and with no vibrations, even if the driver suddenly changes his or her mind about stopping. In addition, since the engine cut-off phases are longer and more frequent than with other systems, fuel savings are higher.
Valeo offers two micro-hybrid systems, either starter-alternator or reinforced starter-based, enabling automakers to introduce this function in line with their brand strategy. Since the system was first marketed, the Group has booked orders to equip 50 vehicle models from more than 10 different automakers.