Physical-based variable geometry turbines predictive control to enhance new hybrid powertrains' transient response

Abstract

[EN] Nowadays, internal combustion engine (ICE) concerns regarding fuel consumption motivate engine developers to research new technologies, including turbocharging, downsizing and hybridization. Variable geometry turbines (VGT) have been specifically developed for spark-ignited (SI) ICE in recent years. The transient response of such engines, critical for the new certification cycles and drivability, is mainly governed by the VGT management. This work proposes a physically-based control strategy to govern the VGT position to improve the overall system response. The control system evaluates at each considered time step the VGT position providing the maximum feasible turbocharger acceleration through the energy balance along the turbocharger, considering inertia and physical constraints. Once developed, the strategy is evaluated on a fully-validated one-dimensional engine model under heavy transient load demand operation. The model results are compared with experimental data based on a proportional-integral-derivative controller calibrated for the same transient manoeuvre. The new approach showed equivalent or faster transient dynamics with a substantial reduction in calibration time, reducing the time for implementing new turbocharger technologies for future powertrains. Furthermore, the proposed control's highly physical basis allows for its application to any other fuelled thermodynamic system, including a variable geometry turbine.