Research On Modeling And Simulation Of Marine Electric Propulsion System

The advantages of marine electric propulsion systems are numerous,making traditional propulsion systems hard to see.This article takes the electric propulsion system of a typical electric propulsion ship as the research object,and models and simulates the diesel generating set,propulsion motor and ship-propeller system of ship electric propulsion system,and systematically studies the control algorithm of asynchronous propulsion motor.Completed the following research work:1.Aiming at the modeling and simulation of the synchronous generator set in the all-electric propulsion ship system,a seven-order basic model of the synchronous generator set was deduced.Then ignore the stator winding transients,the quasi-set sub-voltage equation in the ? is equal to about 1,through the above two hypotheses operation,from the seven-order basic model to get the engineering application model,that is,the fifth-order practical model.2.A simulation model of a diesel generator set in a marine electric propulsion system is constructed,and a power system model is formed with a load on an actual ship replaced with a static load model.Through the dynamic load test of the established system model,the correctness of the model is verified,and the changes of the system parameters under different disturbances are analyzed.The analysis results show that the diesel generator set system designed in this paper can meet the specification requirements and have the correct.3.A concise comparative analysis of the vector control and direct torque control of the propulsion motor is adopted.Based on the vector control(rotor field oriented control),the static and dynamic performance problems of the AC speed regulation system are theoretically solved,and its dynamic performance is good.Due to the wide speed range,the vector control scheme was finally determined.The mathematical model of the motor is established on the basis of the coordinate transformation theory in vector control,and the rotor flux oriented vector control is mainly described.The rotor model with rotor flux oriented vector control is given.4.In the MATLAB/Simulink simulation platform,a complete closed-loop vector control system model of torque and flux linkage is built.For the built system model,the simulation tests with unchanged load and rotation speed and load and torque allchange.In the whole simulation process,the rotation speed in both cases can be stable with the given value,and the reaction speed is fast.It takes a short time to complete the transition in a short period of time,and the performance of following and suppressing disturbances is good.The simulation results confirm that the asynchronous motor vector control system has strong anti-load disturbance capability and the correctness of modeling.5.Based on propeller characteristics,a mathematical and simulation model of the ship-propeller system was constructed.Detailed analysis of the simulation results of two startup methods: direct startup and staged startup,concludes that the classification startup is more conducive to the stability of the system.In the full text,a complete ship electric propulsion system was finally established and the system model was simulated and analyzed.The results verified the stability of the built system and the correctness of the model.