Research On Simulation Of Marine Diesel-electric Hybrid Power System's Modes

With the increasing requirements of the ship industry on the performance and reliability of the power system and the increasingly strict requirements of Marine organizations on ship emissions,the ship power system has been developing towards the direction of hybrid power.Marine diesel-electric hybrid propulsion has the advantages of traditional diesel engine and electric drive,and has higher reliability and economy.There are many propulsion modes for marine diesel-electric hybrid propulsion,and the switching between the modes and the matching of operation conditions are very important to improve the operation efficiency of the marine propulsion system.Therefore,this paper studies the simulation of marine diesel-electric hybrid propulsion system,hoping to promote the development of marine diesel-electric hybrid propulsion technology in China.At first,this paper deeply studied the diesel-electric hybrid propulsion system the basic structure and composition,clear the research object.First of all,depending on the type of ship's load characteristic determine motor which selects the superior control performance of the PMSM as the shaft generator and the propulsion motor.Therefore,in-depth study of PMSM with body structure,the basic principle of vector control,for motor,the analysis of the mathematical model,designed a double closed-loop vector control system used SVPWM modulation.For the generator,the mathematical model and the rectifier control system are established by using the method of current feedforward decoupling and designing the topology of the controllable rectifier circuit.Then,by analyzing the physical characteristics of each component of the diesel engine,the equivalent mathematical model is established,and finally,the diesel engine module is built with the volumetric method.Then,the four-quadrant mathematical model of the adjustable pitch propeller is established through the open water characteristic diagram of the propeller and the empirical formula,and the ship motion and the interference separation structure model of the propeller are taken into account,and the ship propeller load model is built.Then,the control strategy of power distribution is analyzed and designed by taking into account the factors that affect the economy of marine diesel engine during navigation.Finally,in the MATLAB/Simulink mathematical modeling software,the diesel engine,propulsion motor,shaft generator,propeller and hull model are combined to build a simulation model.The different working modes of Marine diesel electric hybrid propulsion system are studied by simulation,mainly including diesel propulsion mode economic mode PTH mode and Booster mode.A rule-based control strategy is used to allocate the power,which verifies the reliability and feasibility of the hybrid power ship in each mode.