Optimal Navigation Routing And Energy Management Strategy For A Novel All Electric Ship Propulsion System

In recent years,the marine industry of China has entered a stage of rapid development with the strong support of the country.Under the current economic development background,ships have become the most common means of transportation.However,with the large-scale use of ships,the energy consumption and gas emissions have increased significantly,and consequently,marine ecological pollution has become an urgent problem to be solved and a vital factor that restricts the development of marine industry.Therefore,as energy conservation and gas emission reduction have gradually become the mainstream direction of the world’s manufacturing industry,the energy reservation problem of ships has also become an important research topic in the shipping industry,which is related to the saving of fuel resources,environmental protection and economic benefits.All electric ships have gradually received more and more attention due to their low pollution and high working efficiency.To meet the demands of energy saving,emission reduction,economy and safety of ships for world’s ship-building industry,this paper designs a novel allelectric ship power configuration system,which combines the traditional diesel generators with hydrogen fuel cells,battery energy storage systems,photovoltaic power generation systems and cold-ironing technology to satisfy the requirements of propulsion and service loads of ships.The configuration system is used for the coordinated operation and management of ship,thereby laying the material foundation for a more environmentally friendly and energy-saving management strategy.Based on the proposed power system configuration,this study establishes a mathematical model of the optimization problem,which aims at minimizing the total operation costs and greenhouse gas emissions,and taking the navigation routes,power devices and power operating conditions as constraints.The navigation and power generation strategies of ship are linked by the exponential relationship between propulsion load and navigation speed,which is also referred as joint navigation and power generation planning.To solve the proposed mathematical model and optimization problem,this research proposed a bi-level multi-objective optimization method.The upper level uses a multi-objective differential evolution algorithm,where the operations such as differential mutation,crossover,and non-dominated selection are applied,in order to optimize the navigation routes,weight between two objective functions and the capacity of fuel cell and battery energy storage system;the lower level uses the variables obtained from the upper level to solve its optimal power generation scheduling strategy through commercial optimization tools.The two levels of proposed model iterate until the optimized solution set and its corresponding energy management strategy are obtained.An actual sailing route from Dalian to Singapore is used for the simulation of proposed mathematical model and optimization algorithm,and six case studies are conducted to prove the accuracy and effectiveness of the solution.Sensitivity analysis is also applied to highlight the superiority of the bi-level algorithm.