Analysis And Design Of Direct Torque Control System For Permanent Magnet Synchronous Motor Based On Propeller Load

With the continuous improvement of science and technology in China,there have been more and more patent research,ship propulsion from mechanical propulsion to the development of electric propulsion,both at home and abroad have a lot of new research content.At present,the development in our country is still in the embryonic stage in the development of marine electric propulsion,control system and independent design and there are still many problems,so the research on various aspects of ship electric propulsion is very necessary,especially important in model research,the electric propulsion technology development a big role in promoting.This topic has carried on the simulation research to this.In this paper,the characteristics of permanent magnet synchronous motor(PMSM)and the control method of direct torque control are analyzed.The mathematical model and MATLAB/Simulink simulation model are established.Aiming at the problem of unfixed switching frequency,torque fluctuation and other direct torque control,then analyzes the direct torque control system based on space vector modulation,focuses on the analysis of the flux model,the stator flux to the problem,at the same time,was established in the MATLAB/Simulink environment SVM-DTC control system simulation model.The results show that SVM-DTC can significantly improve the stability of the system,but also effectively reduce the torque ripple generated by the permanent magnet synchronous motor,and greatly improve the control performance of the system.Due to the ship in the process of navigation will be subject to many aspects of resistance,such as hull friction resistance,eddy current resistance,wave resistance,etc..In this paper,because of the irregular wave resistance and the establishment of an effective mathematical model,two aspects of ship hull resistance and wave resistance are considered.Iterative not depend on accurate mathematical model of the dynamic system,it learning control was an offline learning process,can the value of signal size with a given value of size difference to repair the instability by comparing the output,so as to produce the control signal stability,improve the stability and tracking system.In this paper,there are obvious advantages in stabilizing the wave load.In the end this paper introduces and analyzes the principle and mathematical model ofship propeller,and the establishment of a ship propeller simulation model in MATLAB,and joined the wave resistance in propeller model,combined with the iterative learning control algorithm,a direct torque control system simulation iterative learning model based on the simulation of the two models the direct torque control,iterative learning system can be very good suppression of interference waves caused by the load on the ship,stable operation,and has certain practical significance.