Research On Control And Simulation Of The New Type Of Marine Dicscl-Electric Hybrid Power System

In order to solve the problems of marine environmental pollution and energy shortage,it is necessary to upgrade the marine power system.At present,the marine power system is transformed from the traditional single-drive diesel engine to the hybrid power system.Under the premise of ensuring the power performance of ships,hybrid power system emphasizes the importance of economic and environmental performance.In addition,it is in favor of the development of intelligent ship.Among them,diesel-electric hybrid ships stand out among the new energy ships.Combining the advantages of diesel engine and motor,the system has already catered to the concept of "two-machine complementarity" of hybrid power system.Meanwhile,it has implemented the national policy of energy conservation,environmental protection and marine power,which will draw a widely public attention in the future.Taking “Zhejiang fishery scientific research ship 2”as the research object,the speed control of the propulsion electric machine of the diesel-electric hybrid power system,power distribution control and acceleration performance under maneuvering conditions are deeply studied.And the system has highlighted the advantages of the diesel-electric hybrid power propulsion system as the propulsion system of the scientific research vessel.According to the navigation characteristics of "Zhejiang fishery scientific research ship 2",the design requirements of the scientific research ship,the design principles of propulsion devices and the configuration forms of power system are put forward.The matching design of propeller is carried out by using the matching method of traditional chart-searching method and optimum propeller speed method.Then,the effective power and propeller parameters of ship are calculated.The ship speed is predicted and the three typical working conditions of scientific research ship are expounded.In order to meet the demand of fast dynamic response and control performance of diesel-electric hybrid ship,this chapter takes the propulsion motor in electric propulsion system as the research object,which builds the motor model by using the software of Matlab/Simulink and adopts the direct vector control of rotor field orientation as the motor speed control method.The control method is mainly through coordinate transformation,and the motor's torque control and flux linkage control are decoupled.Only in this way,the motor's speed can be more precisely controlled to meet the navigation requirements of scientific research ships.On the basis of the characteristic curves of marine diesel engine and motor,the analysis model of ship-engine-propeller is established by using the simulation software of Matlab/Simulink.The different responses of motor and diesel engine start-up in port ships during the motor navigation stage are studied,and the performance of the motor and ship is predicted.By comparison,it is proved that the motor has the advantage of fast response and good maneuverability.Based on the knowledge of diesel-electric hybrid power system,the hybrid power analysis model is established by using the simulation software of Matlab/Simulink.Taking the equivalent fuel consumption as the evaluation index,the control strategy of self-adaptive adjustment of dynamic optimal mixing degree based on active identification mode is introduced.Meanwhile,the three-stage dynamic mixing degree is established,and the system is controlled under three typical working conditions.More importantly,the system can achieve power adaptive matching,so that both diesel engine and motor work in high efficiency area,thus reducing fuel consumption and cost.