Marine Electric Propulsion System Simulation

In order to study the characteristics of marine electric propulsion system,the modeling and simulation research was carried out with the electric propulsion system of Offshore Oil 301.The ship electric propulsion system is a complex system.The research content of this subject mainly includes main propulsion motor modeling,propulsion motor speed control,inverter modeling,ship propeller modeling and visual simulation program design of propulsion system.All mathematical models are verified by MATLAB/Simulink simulation platform and then implemented.The prototype of the propulsion motor is a marine low-voltage three-phase asynchronous motor.The model is modeled by the mathematical model of the universal asynchronous motor under the assumption that the ideal condition is established.The motor speed control method is a direct torque control method with high torque dynamic response.The distribution of space voltage of the stator winding of the motor in the delta connection and the star connection and the corresponding sector calculation method are given.The prototype of the propeller is a "Z" type towed propeller,and the working characteristics of the propeller are obtained by interpolation of the experimental data of the open water characteristic of the propeller.On the basis of model modeling,the ship propulsion model is simulated,and the simulation and actual data are compared between the two conditions and the speed measurement conditions.The correctness of the model is verified and the characteristics of the ship’s propeller are analyzed.parameter.By comparing with the actual data,the simulation model has a certain precision,and can simulate the ship propulsion performance.Through the simulation analysis of the two starting conditions,the sudden change of the propeller torque is because the inertia of the motor and the inertia of the ship have a big difference.When the motor accelerates,the ship’s speed cannot be accelerated in time,which makes the propeller speed decrease sharply and the load is sharp.Become bigger.In view of this situation,considering the acceleration of the ship’s speed during the acceleration of the motor,the sudden change of the propeller load can be improved.The simulation program is designed with the front-end interface,data sharing area and model calculation structure.The front-end interface adopts Microsoft Desktop Display Framework to achieve better display effect.The data sharing area is implemented by static class of resident memory.Model computing program modeling uses an object-oriented approach to achieve maximum reuse of the model.Through the establishment of the propulsion system model,the simulation program studied in this subject can carry out the performance analysis of the ship propulsion system,the operation training of the electric propulsion system,and the research of other speed control algorithms.