Abstract
KEYWORDS
hybrid electric vehicle, powertrain, bond graph, dynamic modeling
ABSTRACT
The purpose of this paper is to present the authors’ vision upon dynamic modeling of complex hybrid electric automotive powertrain systems. Emphasis is on bond graph modeling technique, which is a link between physical (real) model and its mathematical description. The bond graph method is a visual interface that allows the engineer to focus on system configuration and representation – rather on the set of differential-algebraic equations. Throughout the last years, this method entered into the engineering field, especially when dealing with control problems of medium and large systems, because it has the advantage of providing a direct meaning of system’s states. Moreover, there are dedicated software tools that automatically generate the dynamic system’s equations set directly from the bond graph. Combining all these advantages, the authors present some top-level models of hybrid electric propulsion systems for automobiles, without entering into details. For this reason, a generic word bond graph is usually presented first, with power bonds having a clear physical meaning. Then, a powerful similarity between bond graph method and SimulinkTM block diagram – based models is discussed, following the concept of causality. As a conclusion, the authors emphasize on the method’s degree of suitability for the fast deduction of system’s governing equations, as a starting point in developing large simulation models.