Study Strategies Of Permanent Magnet Synchronous Motor Direct Torque Control Based On Ship Electric Propulsion System

Ship electric propulsion technology has advantages of good maneuverability, saving fuel cost, easy maintenance, etc.It has become a hot research topic in domestic and overseas. In order to refine and improve permanent magnet synchronous motor direct torque control technology (PMSM DTC) for marine electric propulsion system and provide a theoretical basis,the direct torque control technique of permanent magnet synchronous motor was studied in this paper.Firstly, the research value of marine electric propulsion system which applied the PMSM-DTC was concluded. And the development history and research status of the electric propulsion technology and direct torque control technology has been elaborated. Then, the traditional DTC and SVM-DTC simulation models were built, by analyzing the PMSM mathematical model and the achievement methods of DTC.After that, the PMSM DTC was achieved by built a DTC experiment platform and completed the control algorithm programming and debugging.Finally, by analyzing the relationship between the power factor angle of PMSM and flux value given, a given value of flux calculation method to control motors running under the given power factor angle was derived and an optimized adaptive flux unity power factor control strategy was also proposed. After built the simulation model, the correctness of the method was proved. Meanwhile, based on the study of mathematical model on a ship propeller, a comprehensive simulation model of ship electric propulsion system was established and the optimized control strategy was applied to it. Simulation results show that the control strategy can control the propulsion motor operate under unite power factor in marine electric propulsion system.Once again proved the effectiveness of the proposed method.