| Summary: | The design of green ships has received significant attention with the goal of reducing the negative environmental impacts of shipping and to comply with the more stringent environmental regulations. Therefore, in 2009 the International Maritime Organisation (IMO) published the Energy Efficiency Design Index (EEDI) measures to be adopted by new ships to reduce the Greenhouse Gases (GHG). Hybrid electric power and propulsion is one of the EEDI measures and fuel cell technologies are considered as a candidate to be used due to their high efficiency, lower emissions, lower maintenance, and quiet operation. This project aims to investigate the use of hybrid propulsion systems for marine propulsion which utilise fuel cells as a main source of power and the effect of energy management on the performance of these systems through voyage simulation. In order to assess the effectiveness of fuel cells as a source of power for ship propulsion systems, the development of a time-domain three degree of freedom total ship system simulator using MATLAB/Simulink is completed. Different components of the ship, including its propulsion system, and the ship's interaction with the surrounding environment are mathematically modelled. Considered power sources in the thesis include conventional two and four-stroke diesel engines, fuel cells and batteries to enable the comparison between conventional and hybrid fuel cell power trains. The verification and validation of the developed ship system simulator are also conducted using numerical, experimental and real ship operational data. The thesis demonstrates the use of the developed total ship system simulator in proposing a hybrid fuel cell/battery propulsion system for a domestic ferry. The results indicate that the hybrid fuel cell system has less weight and requires less space than the conventional diesel system. However, the hybrid fuel cell system's associated costs are still higher than diesel propulsion system. For hybrid fuel cell systems, the design of a suitable energy management strategy is essential in order to handle properly the required power split between the fuel cell and the battery systems. Therefore, the developed ship system simulator is also used to study and compare the most common energy management strategies. An improvement to the classical proportional-integral controller based strategy is presented in this thesis. This improvement results in minimizing the fuel cell operational stress and hydrogen consumption. Alongside this work, a novel multi-scheme energy management strategy with a main objective of reducing the total consumed energy is also developed for the world's first fuel cell passenger ship.
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