Simulation Investigation Of Ship Propulsion System With Shaft Generator Dynamic Performance

With the global energy crisis,the oil prices have rose increasingly,leading to a growing of ship’s operating expenses,and the ship shaft generator can make full use of the engine’s power reserve,which can partially or completely replace the conventional diesel generators for ship power supply,so it can help save the operation cost.In order to make shaft generator provide stable power,the controllable pitch propeller can be used with shaft generator,to keep the ship’s main engine working on constant speed mode.The main engine,propeller and shaft generator have different operating characteristics,so not only should the working characteristics of individual components be considered,but also is the characteristic of the whole system concerned.This paper aims to studying on the whole propulsion system simulation with shaft generator,which is applied to 13000 DWT chemical ship,finally,the dynamic performance of the whole system is analyzed.Firstly,this paper introduces the principle of synchronous generator,and the mathematical model is deduced in theory of synchronous generator.Based on ZFC6506-44 E self-excited three-phase brushless synchronous generator,the simulation model in the MATLAB/SIMULINK environment is built,and the dynamic simulation and experimental verification are started.Then based on experiment data,the diesel output torque model and the speed controlled model are established.In addition,based on the Wageningen B-screw series,the propeller law is studied,and is combined with the open water characteristic curve of 13000 DWT chemical ship’s propeller,to get the CPP model.Finally,the resistance of ship,wake,thrust deduction and other factors are concerned,the ship propulsion system simulation model with shaft generator is established by the balance of shaft rotation and ship hull translation.Considering the operating conditions of shaft generator,the ship should sail on a constant speed mode of main engine.This paper realized to change ship’s speed on constant speed mode by the controlling of propeller’s pitch,simulated and analyzed the ship propulsion system and shaft generator’s performance,the result shows that the dynamic performance of shaft generator frequency,voltage and other performance parameters can meet the requirements of ship power,namely the shaft generator can be operated stably.And then simulated the propulsion system dynamic performance when the ship electric load changed suddenly,the simulation results show that the bigger does mutation of power load increase,the bigger is the fluctuation range and propulsive performance the parameters of the system,the maximum fluctuation speed value is 0.005%,so It can be approximately considered that it has no effect on the ship’s speed,when the load of the shaft generator is changed.The simulation model and result analysis set up in this paper provide theoretical support for the design of the shaft generator and the application in the propulsion system of the ship.