Simulation And Modeling Analysis Of Permanent Magnet Direct Drive Wind Power System

With the increasingly serious environmental problems,the issue of clean energy is attracting attention from all over the world more and more.Wind energy,as a typical clean energy,is attracting attention from practitioners day by day.With the increasingly mature technology of wind power generation,the application range of it is getting larger and larger.Considering the large change range of wind speed,in order to ensure stable and efficient power output,high requirements are put forward for the control strategy.Based on this background,in this paper,study the model of permanent magnet direct drive wind turbine and solve mainly the problem of control strategy of permanent magnet direct driven wind motor.The control strategy is divided into side converter and the grid side inverter.Aiming at the problems of short circuit faults in the current power system,discuss the low voltage ride-through scheme of fan aiming at voltage drop problem in this paper.Based on the application background of new energy power generation technology and the research status of wind power generation technology,the wind power generation system is classified,and two kinds of variable speed constant frequency power generation systems are introduced.The driving principle and characteristics of permanent magnet direct drive wind power generation system are introduced,and the mathematical model of permanent magnet direct drive wind power generation system is constructed.The structure diagram of machine side converter and grid side inverter is given respectively,and the mathematical model of machine side converter and grid side inverter is deduced.Research and analyze the control strategy of permanent magnet direct driven wind turbine.The maximum power point tracking strategy is studied.Based on that,the control strategy of the grid side inverter is deduced and analyzed,and the double closed loop control strategy taking current as inner loop and voltage as outer loop is determined.The PI control parameters of the current inner loop and the external voltage loop are derived respectively,and the final control scheme of the net side inverter is determined.After determining the control scheme of the grid side inverter,study the control strategy of the converter of the machine side control system,and the parameters of every link in the double loop structure are determined in the same way.Aiming at the control scheme of grid side inverter and machine side converter proposed in this paper,simulation analysis is carried out in this paper to verify the effectiveness of the control strategy proposed in this paper.Aiming at the phenomenon of voltage sag with a certain frequency in power system,the characteristics and detection methods of voltage sag are discussed.The phenomenon of low voltage ride through is introduced,and the standard of low voltage ride through in different countries is given.The basic principle of low voltage crossing technology is discussed,and the final scheme of unloading circuit is determined.The proposed low voltage ride through scheme is applied to the permanent magnet direct drive wind power generation system,and its effect is analyzed by the overall simulation.The simulation results verify the effectiveness and reliability of the proposed method strongly.