On-line energy and battery thermal management for hybrid electric heavy-duty truck

This paper discusses an integrated approach for energy and thermal management to minimize the fuel consumption of a hybrid electric heavy-duty truck. Conventional Energy Management Systems (EMS) operate separately from the Battery Thermal Management System (BTMS) in Hybrid Electric Vehicles (HEVs). Specifically, the latter system tries to keep the battery temperature always at a predefined level and requests a non-negligible amount of energy. The EMS then provides the energy demand from the BTMS without checking whether its action is fuel beneficial. In this paper, a fuel minimization control problem is defined to handle the trade off between the cost and benefit of the BTMS for the hybrid powertrain. A real-time implementable control strategy is derived and its robustness is tested with different driving cycles as well as ambient temperatures. Improvements up to 1:8% fuel savings compared to a non-integrated approach are shown by simulation results.