Modelling and Energy Management of Hybrid Electric Vehicles

Economic and social growth has long been associated with the performance of various means of transport. As far as land transport is concerned, the various mobility sectors (personal transport, public transport services, freight transport, etc.) have benefited from the technological development of increasingly efficient, mainly thermal, engines, which have become a widespread part of human activity. However, these same means of transport, based on energy consumption of predominantly fossil origin, are now associated with various environmental nuisances, such as global warming and air pollution. On the other hand, the predicted end of fossil fuel reserves calls into question the supremacy of thermal propulsion in transport. Although combustion engines (gasoline, diesel, gas) have made significant advances in efficiency and pollution control over the last few decades, the search for alternative powertrains incorporating electricity has not ceased since the introduction of the first electric vehicles. Solutions combining both internal combustion and electric motors, known as hybrids, have also been studied and developed. Aimed at exploiting the advantages of each type of energy, this category of vehicle can theoretically provide the same mobility services as a conventional vehicle, while controlling environmental pollution, particularly in urban and suburban areas. This is because, in addition to being able to operate in an emission-free mode like an electric vehicle, the second source, generally based on fossil fuel, enables the vehicle to maintain a range comparable to that of a combustion-powered vehicle. Switching from one operating mode to the other enables the hybrid vehicle to adapt to traffic conditions, thus ensuring remarkable energy efficiency, especially as deceleration and braking phases are generally accompanied by recovery of the vehicle's kinetic energy, to recharge the storage element.

On the other hand, the presence of several sources, and therefore several on-board energy conversions, raises two major concerns. The first is economic, and raises the question of the possibility of amortizing the additional investment costs generated by the addition of additional components compared with a combustion-powered vehicle. The second is of a technical nature, and concerns the complexity of implementing the powertrain, with its multitude of possible combinations, as well as the complexity of synthesizing the control system that will manage the operation of the vehicle and all its components.

It is in these two areas in particular that research over the last few decades has led to the use of a systems approach to the vehicle, based on modeling. High-level hybrid vehicle control, also known as "energy management strategy", is fully in line with this approach,...