Grid-connected Control Simulation And Dynamic Model Test Of Doubly-fed Wind Turbines

The rapid development of economy has accelerated the process of fossil energy depletion and environmental pollution.Green and clean wind energy has become the focus of new energy development in the world.The single machine capacity of the wind turbine is getting bigger and bigger,Its influence on the grid cannot be ignored,the control of connecting to the grid is a necessary technology for wind power generation.Based on this,this paper studies the hot issue of Doubly-fed Induction Generator(DFIG)connecting grid,introduces power transmission relationship of Doubly-fed Induction generator and the basic working principle of Doubly-fed Induction Generator,including the principle of Doubly-fed Induction Generator in variable speed constant frequency operation?its operation characteristic and also introduces the mathematical model and coordinate transformation principle of Doubly-fed Induction Generator in different coordinate system.Then,based on the control strategy of Doubly-fed Induction Generator,the modeling and Simulation of the wind turbine and the stator voltage orientation of the Doubly-fed Induction Generator are introduced.The control strategy of the stator voltage orientation of the Doubly-fed Induction Generator is introduced.The control of connecting to the Grid is only the first part of the DFIG operation control.In order to complete the off-line simulation of the DFIG connecting grid process,the power generation control strategy after connecting the grid is also introduced,and then simulate the whole process completely.Because the software simulation can only be used to learn and test the basic principles and algorithms,ignore the realization of the hardware system of the final prototype,a set of control platform for induction motor is developed in this paper,using the universal real time simulator platform(UREP)developed by the group.It is carried out in the experiment of open loop speed regulation of asynchronous motor,DC excitation experiment of Doubly-fed Induction Generator and AC excitation experiment of Doubly-fed Induction Generator for power generation.On the basis of a series of experiments on the asynchronous motor closed loop speed control and vector control experiment and so on,the asynchronous motor is the original motive and the Doubly-fed Induction Generator is the generator.At last,the requirements for grid connected control of DFIG are achieved.The simulation and experimental results show that the control strategy is true and feasible.