Paper Title
Stop-Start System Using Micro-Hybrid Technology For Increasing Fuel Efficiency

The national mandate set forth by the Environmental Protection Agency (EPA) to increase fuel efficiency and reduce greenhouse gas (GHG) emissions by 5% each year for all new model mid-size cars, medium-duty cars, and light-duty trucks is pushing automobile makers to convert their fleets to hybrid-electric and micro-hybrid vehicles. Implementing automated start/stop (SS) technology in a passenger vehicle is a cost effective way to improve fuel economy (FE) and reduce emissions without affecting consumer acceptance. In urban areas, where much of the vehicle driving time is spent idling at stop lights or in traffic, the engine can be shut down when the vehicle is stopped to save fuel. The engine is quickly and quietly restarted as the driver demands torque for acceleration. This operating strategy is often utilized in full hybrid-electric vehicles that have powerful electric systems, but is becoming more popular in micro-hybrid vehicles that use traditional starter/battery configurations. It is challenging to maintain drivability and achieve efficient start-ups using a micro-hybrid configuration. This research investigated the feasibility of using a micro-hybrid configuration to achieve efficient start transients for SS technology. The consumption of energy by the starter/battery was analyzed by creating a model of the engine SS dynamics. The model was calibrated and validated through experimental testing on a vehicleand engine that had been provided. The model was used to simulate start transients for different component packages. As the preliminary simulation results which suggest that traditional starter/battery combinations may be appropriate and a fuel savings of over 5% expected in regulatory urban driving cycles. The model and selected component package will be used for development and control of a SS system in a test vehicle.