engleski

System design and control optimization of marine hybrid energy systems

The interest in designing more efficient ships stems from increasingly stricter emissions regulations. One of the ways this can be done is by remodelling the power system and its energy management strategy e.g., replacing classical marine propulsion systems based on diesel engines with a more modern hybrid architecture. Adding options in power management allows individual power sources to work closer to their optimal operating point. The marine hybrid system provides solutions to the problems of poor performance at low loads when the internal combustion engine is the main engine of the ship. Matching and selecting a hybrid system plays a significant role in efficiency and energy savings. In order to improve performance with these architectures, modern power management strategies are needed. This paper analyses a marine propulsion system for a ferry that combines conventional propulsion with an internal combustion engine and electric propulsion with parallel control so that both types of propulsion are maximally utilized. Electricity is supplied by a battery to save fuel and reduce emissions at a given load profile. The battery can be charged directly via the power grid, but also via photovoltaic cells. The model is developed with AVL Cruise-M software package. Adoption of the hybrid system has made it possible to reduce fuel specific consumption, on a given route (local ferry line approximately 9.2 nautical miles long in one way), by about 7 % compared to the case where only a diesel engine is used. A major influence on the choice of batteries in the future depends on solar irradiance, which greatly contributes to increased fuel economy. Comparing morning and afternoon navigation, there is a difference of up to 15 % in the charge of the battery itself, which speaks for the potential of photovoltaic cells in countries with a large number of sunny days.

Hybrid ships, System modeling, Control optimization

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