Research On Sensorless Control Strategy DIFG System

At present,with the rapid development of social science and technology,people's dependence on energy is particularly important.Wind energy is a kind of clean energy and renewable energy,so the energy industry and other fields have been widely used and have important practical application value that the doubly-fed asynchronous generator is an important core control part of the wind power generation system.The doubly-fed asynchronous wind power generation system has the characteristics of low cost,high stability and simple control.Therefore,it has important research significance to control the doubly-fed wind power generator.In this paper,the control strategy analysis of doubly-fed asynchronous generator and machine-side AC in doubly-fed asynchronous wind power generation system is studied,and the fault of a bridge arm of the machine side converter,the finite contro l set model predictive control and the speed sensorless control are deeply studied.Firstly,it expounds the significance and practical value of this research and analyzes the research and development trend of doubly-fed asynchronous wind power generation system in China and abroad.At present,the control scheme of the machine side converter is described and analyzed in detail,and The research status of finite control set model predictive control at home and abroad and the application of power electronics technology are analyzed in detail;at the same time,the present situation and practical situation of speed sensorless control technology are described.Secondly,the basic structural components of the doubly-fed asynchronous wind power generation system are expounded.The examples of different coordinate correlations and transformations and their corresponding examples are given,and the mathematical model and state equation of doubly-fed asynchronous wind turbine(DIFG)system are constructed in two-phase static ? ? coordinate system and two-phase rotating dq coordinate system.the topology and output voltage of the NPC type three-level inverter are given;and,the basic principle of finite control set model predictive control(FCS-MPC)is introduced in doubly-fed asynchronous wind power generation system.Thirdly,a kind of three blades can be built to change oars independently and Wind turbine experimenter that can yaw in the engine room.The software of measurement and control system is compiled,which can control the variable propeller and yaw mechanism,measure the increasing and decelerating process of the experimenter,draw the angle acceleration curve of the experimenter,and the curve of the bias load characteristic.The deceleration curve measureme nt and bias load characteristic measurement experiments are carried out in wind tunnel by using the designed experimental instrument and measurement and control software,and the experimental results and theories are analyzed.At the same time,the basic pr inciple of maximum power tracking control is analyzed.Then,the reason of the unbalance of the DC point of the DC side of the NPC type three-level inverter is analyzed,which the topology structure and output voltage model of the fault-tolerant control are established.The mathematical model of finite control set model predicting direct torque control(MPTC)is constructed for doubly-fed asynchronous wind turbine system(DIFG),and the delay of the system is compensated accordingly.Finally,according to the advantages of fractional sliding mode control,the observers of DIFG system speed,stator current and rotor flux linkage are designed based on fractional sliding mode control.The shortcomings of FCS-MPC strategy are analyzed,and the FCS-MPTC strategy is constructed based on sliding mode control,At the same time,a speed regulator based on sliding mode control is designed.