Research On Speed Sensorless Control Strategy Of Wind Power Generation System

Wind power has become the fastest growing new energy source because of its environment-friendly,high reliability,low cost and significant scale,which requires more mature wind power technology.A lot of physical quantities need to be detected in the process of achieving maximum wind energy capture,and rotor speed is a very important physical quantity.However,due to the poor operating environment of the wind power generation system and the existence of uncertainty,the installation of speed sensor not only increases the connection wires between the wind power system and the control system,but also reduces the reliability of the system,increases the system cost.In order to solve the above problem,according to structural characteristics of the fan and the characteristics of the operating environment,this paper builds the overall mathematical model of the system and designs the perfect control system to realize the speed sensorless control,at the same time,as much as possible to consider the possible uncertainties of the system and external disturbances,so we can ensure that the system is stable,safe,reliable and efficient operation.The specific research contents are as follows:Firstly,the structural characteristics of the wind power system and the running characteristics of the wind turbine are analyzed.Considering the parameter perturbation and the system disturbances during the operation of the system,the mathematical model of the permanent magnet synchronous wind turbine system is established.Then,according to Hamiltonian system passive theory to establish the port controlled Hamiltonian model of the permanent magnet synchronous wind power generation system.Then,on the basis of the previous chapter,the system controller is designed to achieve speed sensorless control.Firstly,design the system passive controller to shape the energy function,which makes the system energy function achieve the minimum value in the desired balance point;the adaptive full-dimensional state observer is designed to estimate the speed of the permanent magnet synchronous wind turbine system.Finally,aiming at the system perturbation problem,the extended state observer is designed to observe the system disturbance and compensate dynamically.Finally,compare and analysis the characteristics of the sliding mode expansion state observer and the traditional expansion state observe,respectively.The sliding mode expansion state observer has the advantages of both the sliding mode and the extended state observer.It can be used to estimate the total disturbance and speed up the convergence rate.Based on the previous chapter,it is proposed to solve the problem of system perturbation by using the sliding mode expansion state observer to estimate and dynamically compensate the system perturbation.Theoretical analysis and simulation results show that the proposed control method can solve the control problem studied in this paper.