Abstract
Global warming, the decline of natural resources as well as the strengthening of emission regulations have led to a research focus in new drive technologies. Within the group of alternative propulsion systems, fuel cell hybrid electric vehicle (FHEV) are considered especially promising.
Since system efficiency as well as the operation characteristics are determined by the chosen energy management system (EMS) scheme, an optimal approach is a key aspect to guarantee optimal system operation in terms of power and energy efficiency, as well as component lifetime and costs. Existing research efforts mostly focus on the optimisation of the hydrogen consumption, while neglecting component degradation as additional important part of total system and operation cost. Furthermore, almost no published work considers the thermal management of a FHEV.
Therefore, the presented work propose a novel model predictive control based energy management approach with a special focus on preventing fuel cell (FC) and battery (BAT) degradation and the vehicle’s thermal management. In order to minimise component ageing and degradation, the objective function which is used in the developed method, includes cost which account for both decreasing BAT state of health as well as FC operation conditions which accelerate the degradation of the FC. To be able to test the developed EMS, a model and a hardware based test environment were developed. Since there are no thermal management systems for FHEV presented in literature, a new concept with a hierarchical control scheme was designed. Because the newly developed energy management shall be tested based on real world data, a method to generate test cases representing typical driving scenarios based on real world driving data was developed and implemented. Finally, the hardware system was used to validate the simulation model and vice versa, the model based approach was validated on real hardware.