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Modeling SI-engines for Hybrid Vehicles
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 5, 2001 by SAE International in United States
Annotation ability available
Event: SAE 2001 World Congress
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.
Most SI-engine models for hybrid vehicles are quasi stationary, which means that data achieved at stationary load conditions are assumed to be representative for transient operation as well. In this paper a concept is presented in which stationary engine data is used, but corrected for the effects of lambda excursions.
In the present paper the model is described in depth and some calculated experiments are presented. It is found that load changes in the range of 20% to 90% at frequencies higher than 0.5 Hz will result in lambda excursions that probably will result in unacceptable emissions.
CitationStrandh, P. and Egnell, R., "Modeling SI-engines for Hybrid Vehicles," SAE Technical Paper 2001-01-0575, 2001, https://doi.org/10.4271/2001-01-0575.
- Almkvist Göran. Transient Air to Fuel Ratio response in a Fuel Injected S.I. Engine. ISBN 91-7197-097-5.
- Egnell Rolf. α -03 Simulinkmodell av en turboladdad ottomotor. ISBN 0282-1990.
- Heywood John B.. Internal Combustion Engine Fundamentals. ISBN 0-07-100499-8.
- Cowart Jim S. and Cheng Wai K.. Trottle Movement Rate Effects on Transient Fuel Compensation in a Port-Fuel-Injected SI Engine. SAE 2000-01-1937.