Abstract
Abstract
The awareness of the negative impact of the CO2 emissions on the climate has lead the European Car Manufacturer Association (ACEA) to propose to limit those emissions by reducing the fuel consumption of their fleet.
Indeed, for a mean value of 186 g / 100 km in 1995, the CO2 emissions should be reduced down to 140 g / 100 km in 2008, the target being 120 g / 100 km in 2012. To cope with this increasing demand of fuel consumption and CO2 emissions reduction, and above combustion engine improvements, Valeo is proposing different solutions, from the most simple and cost effective one allowing only stop-start to more powerful systems able to assist the Powertrain. In particular, a solution based on the use of a double layer capacitor (UCAP) is able to recover one portion of the kinetic energy lost during braking.
The Stop-Start is done by means of a belt driven machine controlled by a full wave DC to AC inverter, thus no high frequency switching giving neither high losses nor EMC compatibility problems, all this in a compact, cost effective electronic module. Once this function has been implemented into the vehicle a simple storage system combining lead acid battery and double layer capacitor (UCAP) allows recovering as much as possible energy without any high cost and risky architecture.