Starting-up And Adjusting Speed Of AC Motor Of Electrical Propeller For Ship

As the prospect of electric propulsion and the great progress of the relevant technologies, AC propulsion is in the leading position. There are several technique of asynchronous motors adjust speed at present, such as constant voltage divide frequency control, vector control, direct torque control, etc. Performance simulation of induction motors frequency conversion adjusting speed is a very significant work for us.Frequency conversion based on Direct Torque Control with asynchronous motor is a modern method with high performance in AC regulating speed, which is simple and clear in structure and is easy to realize digital. This control method depend little on model parameters of motor, and it has become the focus of AC regulating speed field. Although the theory and practical application of DTC are behind vector control, it develops faster and faster because of its own inherent advantages.This paper select asynchronous motor as the electric propulsion motor for ship whose load is screw propeller, and it also models and simulates in MATLAB/SIMULINK environment. Newly developed frequency conversion based on Direct Torque Control is applied in the simulation system of AC motor's start-up and speed regulation for ship in this paper. Besides, the paper describes the principle of Direct Torque Control system, the disposal of inverters, the selection of control method and the model building based on the mathematical model of asynchronous motor. The structure of the model is simple and easy to update. The simulation results indicate the high quality of control performance and preferable applied value of the model. This paper offers us a new method of application and design in speed regulation field for ship using Direct Torque Control with asynchronous motor.