Research On Diesel-Electric Hybrid Propulsion System In Tuna Fishing Boat

Ocean fishery resources are an important natural resource in the marine environment.Development and utilization of ocean fishery could effectively alleviate the current shortage of offshore fishery resources in China,and also have an important strategic for the development of marine economy and the enhancement of international influence in China.Since 21 st Century,the pelagic fishery in China has developed rapidly,but with the rise of international fuel prices,the problem of energy consumption and emissions are gradually emerging.The environmental problems caused by ocean fishing have attracted the attention of all countries.Our country published Emission standards for exhaust pollutants in the first and second stages of marine engines which limits exhaust pollutants of engines.Meanwhile,the "dual-control" policy of fishing boats also strictly limits the number of fishing vessels and the total power of diesel engines.In order to ensure the healthy,efficient and sustainable development of our marine economy,we must achieve low cost,low pollution,low emission and high efficiency.Taking tuna long line fishing boat as the research object,seeking a way to fully exploit the advantages of tuna long line fishing specialty and effectively reduce the fuel consumption and pollutant discharge of fishing boats has always been a common concern.In order to reduce the consumption of energy and enhance the economic benefits of pelagic fishery,a hybrid electric power system is developed for tuna long line fishing boats.The hybrid tuna fishing boat is composed of two main power sources of diesel engine and motor.It possesses the advantages of diesel engine propulsion safety,stability and mature technology,and at the same time,it has the advantages of wide range of electric propulsion,energy saving and environmental protection.The hybrid system of tuna fishing boat can efficiently allocate output of power source and adapt to multiple conditions of fishing operations,so as to reduce the comprehensive fuel consumption of fishing vessels and achieve the goal of energy saving and emission reduction.First of all,according to the analysis of hybrid power system structure,we have studied three driving modes: series,parallel and series-parallel connection,and selected parallel structure as hybrid structure.Then according to the characteristics of parallel hybrid power system,the paper research and analysis the power distribution control strategy,design fuzzy control strategy which could achieve the optimal torque allocation of diesel engine and the electrical motor.Finally,the modeling and simulation of the hybrid system are carried out under the MATLAB/SIMULINK platform.By observing the simulation results,compared with the traditional tuna fishing boats,the fuel consumption of hybrid tuna boats decreased by 19.8%.Therefore,the hybrid system improves the fuel economy,energy saving and environmental protection as well.It proves that hybrid tuna fishing boat has high economic and wide prospects.