Modeling And Controlling Of Marine Permanent Magnet Synchronous Motor

With the increasingly high demand of modern ships in energy saving,mobile navigation,electric propulsion system has become a trend of the future development of the ship due to its high degree of automation,good security and mobility.The permanent magnet synchronous motor plays an irreplaceable role in the electric propulsion system.Meanwhile,in the electric propulsion system ship,propulsion system occupies about 70% of power plant capacity and has a significant impact on power quality.Therefore,it is necessary to research the medium-voltage electric propulsion system based on the permanent magnet synchronous motor,which can provide a theoretical reference for the marine electric propulsion system.In the thesis,the structure of marine electric propulsion system has been analyzed,which includes diesel engine with a governor,generator with excitation system,common load,transformers,permanent magnet synchronous motors and propellers.And corresponding models are developed in Matlab/Simulink.The core part of propulsion system is the motor control algorithm.The vector control system is designed to adjust the behaviors of the motor drive,based on the principle of vector control and space vector pulse width modulation.And the results show that this control system has a good performance.Also direct torque control system is analyzed to be applied in the permanent magnet synchronous motor.The direct torque control system based on hystereris controllers and swithching table is developed in Simulink to control the motor.And the results show this system has fast dynamic responses.The thesis based on the the actual ship "China Railway Bohai No.3 ship" has the simulation analysis.The marine electric propulsion system with vector control and direct torque control are modeled respectively.The dynamic response of the electric propulsion system will be analyzed under different operation conditions.The results are also compared with the actual ship("China Railway Bohai No.3 ship")data to verify the validity of the model.