Implementation of Optimization-Based Power Management for All-Electric Hybrid Vessels

The increasing concern in environmental impacts contributed by the shipping industry leads to a growing interest toward incorporating sustainable energy sources to conventional power systems, to reduce fuel consumption and emissions. However, such advance power system architectures tend to face greater challenges in optimal power allocation due to the increased flexibility to split the load among multiple power sources and diversified operations of different vessel types. To address the power management challenges, in this paper, an instantaneous optimization-based approach is proposed for an all-electric hybrid power system, which adopts the equivalent consumption minimization strategy (ECMS). First, the dynamic models of the all-electric hybrid power system are formulated in MATLAB\Simulink and validated on a laboratory-scaled hybrid power system testbed. The power management problem is then formulated using ECMS approach, and a multi-level power management framework is proposed to integrate ECMS solution for practical implementation on an all-electric hybrid vessel. Finally, the feasibility of the proposed approach is validated on a full-scale setup identical to an actual all-electric hybrid vessel with dc distribution in MARINTEK, Trondheim, Norway. The performance of ECMS is also benchmarked against an improve rule-based strategy. The experimental results demonstrated that ECMS can achieve a substantial fuel savings of up to 24.4% as compared with improved rule-based strategy over one cycle of harbor tugboat operations, with the presence of available shore charging.