Efficiency analysis of hybrid propulsion system for marine vessels

Improvement in conventional propulsion systems or using alternative propulsion systems come to the fore considering the ever-evolving technologies in the maritime industry and IMO energy efficiency measures. IMO MARPOL Annex VI "Prevention of Air Pollution from Ships" determines the nitrogen oxide, sulphur oxide and particulate matter limits emit from marine vessels. Some of the objectives of using different types of propulsion systems on ships is fuel saving, minimizing the release of harmful gases to the environment and reducing operational costs. The aim of the study is analysing the efficiency of the hybrid propulsion system (HPS) in view of fuel consumption applied on marine vessels and highlighted the environmental and cost gains. Comparison of conventional propulsion systems and HPS is performed with the interface developed in MATLAB GUI. The interface includes the selection of HPS equipment such as diesel main engine, electric motor, battery and rectifier in order to perform the analysis. The technical characteristics of the equipment and operational data used are obtained from both quantitative data analysis and experimental studies. Thirty two different analyzes are performed using all the data obtained and findings are recorded over the interface. Mathematical optimization method is used to decide which operation is more suitable for HPS based on findings. According to the findings, the most efficient HPS application is achieved by using lithium-iron phosphate type batteries and asynchronous AC electric motors also the highest efficiency output is achieved as 72.356%. The study will create a resource for academics and industry stakeholders who will work on similar or different ship types in this field.