Optimization and Comparison of Quick and Hybrid Start

A fast and comfortable low emission and energy efficient start of the internal combustion engine (ICE) is necessary for the acceptance of start stop systems. The focus of this research work is how a starter-initiated direct start (Quick Start) performs compared to a start with an integrated starter generator (Hybrid Start).

This paper presents that a Quick Start can be reproducibly run with an optimized throttle strategy during coast down with a competitive start duration compared to the Hybrid Start. The computation of the primary energy consumption for the complete start procedure results in the time that has to elapse during engine shut-off until the automatic stop was beneficial. That time is 1.2s to 1.4s for two different Hybrid Start strategies and 2.0s for the Quick Start.