Search Results

One of the most attractive features of hybrid vehicles powered by SI-engines with three way catalysts is the potential of reaching extremely low emissions. In conventional drive trains, limitations in the air/fuel control result in lambda excursions during transients. These deviations from the ideal lambda result in increased emissions. In a hybrid vehicle, rapid load and speed changes of the SI-engine could be limited to an acceptable level as the battery acts as a power buffer. However, the efficiency of charging and discharging the battery is rather low, which means that excessive power buffering will increase the fuel consumption of the vehicle. Thus it is of great importance to know what degree of speed and load changes the air/fuel control system could cope with without an increase in emissions.