Advanced Ignition Systems: Technical Possibilities and Limitations

Striving for maximum efficiency gains, the highly diluted gasoline combustion process is a key technology to reach 95g/km CO2. Various advanced ignition systems were developed in the past to deal with the challenges with stratified combustion or high dilution. On the one hand they must be capable to generate a high voltage to breakdown the spark plug gap in downsized turbo charged engines; on the other hand they have to supply a big amount of energy in a short time during the burn-phase of the arc.
Due to the proven robustness and cost effectiveness of traditional ignition systems based on fly-back transformer topology, these systems will stay the leading technology within the next years. The present paper is giving an overview of the different advanced ignition systems developed at Delphi – namely the MultiCharge (MCI), the Alternating Current (ACI) and the Coupled-MultiCharge (CMC) Ignition System. The MCI-system is already in mass production and is capable to provide long effective spark duration with a quasi-continuous spark only interrupted for coil recharge. The ACI-system is providing a higher amount of energy to the ignition arc and has an uninterrupted but limited burn time. The CMC-system is combining the advantages of both long, uninterrupted spark and high energy delivery. The technical limitations and benefits of the different systems will be shown in this paper.