Optimization-Based Thermal Control Strategy for Auxiliary Cooling Circuits in Fuel Cell Vehicles

In this research work, a thermal management concept for the auxiliary components in fuel cell vehicles is discussed. A control-oriented model (COM) of the subsystem under analysis is developed and then used as basis for controller development. Two control strategies are implemented and compared. The first is a PI-controller strategy and it is used as a baseline for performance comparison. The second is an optimization-based controller (OBC) strategy focused on minimizing the power consumption of the main actuator. The OBC features a novel steady-state observer (SSO) developed for thermal circuits and provides an estimation of the steady-state conditions and conveniently simplifies the optimization problem by disregarding the dynamics of the states so that it can be implemented online with lower computational burden. Comparisons between PI-control strategy and OBC demonstrate the OBC's capabilities in overcoming typical problems associated with the PI-control strategy including high-power consumption of the actuators and temperature constraint violations under particular operating conditions.