Abstract-The evolution of the use of electricity in marine vessels is presented and discussed in this article in an historical perspective. The historical account starts with its first commercial use in the form of light bulbs on the SS Columbia in 1880 for illumination, going forward through use in hybrid propulsion systems with steam turbines and diesel engines and then transitioning to the present with the first fully electric marine vessel based entirely on the use of batteries in 2015. Electricity use is discussed not only in the light of its many benefits but also of the challenges introduced after the emergence of the marine vessel electrical power system. The impact of new conversion technologies like power electronics, battery energy storage, and the DC power system on overall energy efficiency, power quality, and emission level is discussed thoroughly. The article guides the reader through this development, the present and future challenges by calling attention to the future research needs and the need to revisit standards that relate to power quality, safety, integrity, and stability of the marine vessel power system, which are strongly impacted by the way electricity is used in the marine vessel.

Abstract-The evolution of the use of electricity in marine vessels is presented and discussed in this article in a historical perspective. The historical account starts with its first commercial use in the form of light bulbs in the SS Columbia in 1880 for illumination purposes, going through the use in hybrid propulsion systems with steam turbines and diesel engines and transitioning to our days with the first case of electric marine vessel entirely based on the use of batteries in 2015. Electricity use is discussed not only in the light of its many benefits but also of the challenges introduced after the emergence of the marine vessel electrical power system. The impact of new conversion technologies like power electronics, battery energy storage and the dc power system on the trajectory of this development is thoroughly discussed. The article guides the reader through the different stages of this development influenced by the different forms electricity took in the marine vessel, with emphasis on how electricity was used has impacted the marine vessel power system development.

Abstract-Recently, the efficiency of diesel-electric marine vessels has been subject for discussion with focus on improving fuel efficiency, reducing the environmental footprint from emissions, as well as reducing running hours and maintenance costs. This work presents an analysis of load profiles extracted from three different vessels during operation; a ferry, a Platform Supply Vessel (PSV) and a seismic survey vessel. The analysis of the extracted data shows that the loadings of the diesel engines are typically quite low, and do not fall within the optimal loading range of diesel engines' Specific Fuel Oil Consumption (SFOC) curves. Furthermore, three different power plant configurations are proposed and compared, which include fixed speed (diesel engine generators), variable speed gensets and implementation of an Energy Storage System (ESS). Moreover, Energy Management System (EMS) algorithms based on Mixed Integer Linear Programming (MILP) are proposed as a suitable strategy for optimal unit commitment in the power generation. The results yielded from the MILP algorithms are compared to EMS algorithms based on logic such as if/else statements. The results indicate that optimal EMS algorithms in combination with a revised vessel configuration can increase the operational efficiency, in terms of fuel savings and reduction in genset running hours.

The recent worldwide effort on the environmental issue has led to new regulations on greenhouse gases emissions (GHG), both for land and marine applications. Nowadays, the extensive electrification of transportation systems is a promising choice for this purpose. In this perspective, algorithms for the optimum sizing and management of energy storage systems (ESSs) integrated into already operating shipboard power systems are proposed in this work. The main aim of this method is reducing the power generation system fuel oil consumption, GHG emissions and management costs. This is applied to two case studies (i.e. a ferry and a platform supply vessel), of which load power profiles are available from the on-board integrated automation system (IAS). The results yielded show remarkable savings close to 6% and 32% along the whole ship's life horizon for the ferry and the platform supply vessel, respectively. These results prove that an optimal sizing combined with an optimum management of ESSs may significantly reduce the operative costs of shipboard power systems.

Abstract-This paper proposes a system-oriented approach for mitigating harmonic distortions by utilizing a single Active Power Filter (APF) in an electrical grid with multiple buses. Common practice for control of APFs is to locally compensate the load current harmonics or to mitigate voltage harmonics at a single bus. However, the operation of an APF in a multi-bus system will influence the voltages at neighboring buses. It is therefore possible to optimize the APF operation from a system perspective instead of considering only conventional local filtering strategies. For such purposes, Model Predictive Control (MPC) is proposed in this paper as a framework for generating APF current references that will minimize the harmonic distortions of the overall system within a given APF rating. A diesel-electric ship, with two buses supplying separate harmonic loads, with an APF located at one of the buses, is used as study case. The operation with on-line MPCbased optimization of the APF current references is compared to two benchmark methods based on conventional approaches for APF control. The results demonstrate that the MPC generates current references that better utilize the APF current capability for system-wide harmonic mitigation.