Integrating Fuel Cell, Battery, and Supercapacitors in Hybrid Electric Vehicles: Modeling, Control, and Hardware-in-the-Loop Considerations

To meet the sustainability goals set by the European parliament by 2050 and attain the so-called "net-zero" emissions standard, the automotive industry will need to walk away from traditionally combustion-powered vehicles and develop alternative hybrid powertrains to propel private and commercial vehicles alike. In particular, hydrogen-powered vehicles have a lot of potential, in particular if combined to a battery to palliate the slow dynamics of a fuel cell. However, the production of batteries is resource-intensive and their life cycle can be significantly shortened depending on the use case. In this thesis, a model of a fuel cell electric hybrid light-duty vehicle has been proposed, with the fuel cell paired in series with a downsized battery with respect to the battery-only version. To determine the power delivered by the fuel cell stack to the battery, two types of energy management strategies have been defined, a rule-based control with two working modes and a formulation-based strategy depending on the state of charge of the battery and a tuning factor, optimized with the bisection method. Supercapacitors have been added in parallel to the battery in order to take on the more stringent power requests and have been shown to preserve battery life through reduced C-rates. The associated control logic has been defined as a rule-based control strategy whose parameters have been optimized through two designs of experiment. In order to control the validity of the model and associated control logics, a scaled-down hardware-in-the-loop test bench is necessary. Therefore, a method for scaling down the electric machine has been chosen among the literature, its implementation tested and validated against the results from the full-scale model simulation and its logic reversed to compute the scaling-down factor of the vehicle from the desired scaled-down power request. It has permitted to downscale the electric machine but research must still be conducted for scaling down the power sources components.