Research And Application Of The Multi-Megawatt Wind Turbine IPC System Control Strategy

As the size of Multi-Megawatt Wind Turbine rotor increases, the effects of rotor asymmetric loadscoursed by the wind shear, tower shadow and wind turbulence can be more sever, the fatigue loads act onthe components of the wind turbine increase significantly. So the IPC technology is development rapidlywhich is used for alleviating loads experienced by wind turbines. This thesis researched the IPC technologyfrom the aspects of pitch technology theory, building the simulation model of individual pitch controlsystem, individual pitch system control strategies and software platform simulation. Main work covered inthis thesis is as follows:（1）For the problem of hard to build the wind turbine control model with wind turbine highly nonlinear.This paper presents a method based on the Matlab and Bladed platform jointly set up a multi-megawattwind turbine aerodynamic model. Using aerodynamic module of the Bladed platform to calculate theparameters of the aerodynamic characteristics quickly and combining them with the Matlab platform tobuild the rotor aerodynamic model. Combining the rotor model with other sub-models together to build thewhole wind turbine control model and simulating it with the speed-torque controller below rated windspeed and CPC controller above rated wind speed. Build a wind turbine model for pitch control simulationby combining the rotor aerodynamic model with other sub-system models together. It shows that thecorrectness of the wind turbine simulation model. The results prove that the Bladed and Matlabjoint-modeling method is correct and efficient.（2）According to the theory of aerodynamics, analysis of wind shear, tower shadow and turbulencewind conditions which caused the wind turbine load asymmetry and volatility, elaborate a method of usingthe Bladed to establish the turbulent wind model according to IEC Specification. Analysis of wind turbineoperating characteristics and related factors in different wind regions, Proposed to reduce the load of theblades and other components by using the individual pitch control which is based on the blade root loadfeedback.（3）Based on the d-q coordinate transformation theory, to decouple the3blade root loads into twomutually independent variables, according to the classical control theory, the individual pitch controllerwhich based on the blade root loads feedback control theory is setup for wind turbine control. Compilingthe individual pitch control program and writing it into the Bladed external controller, simulating it with thenormal power generation condition and analyzing the loads-time history. The results show that, tocompare with the PI based pitch control strategy, the load feedback based IPC control strategy cansignificantly reduce the load of the components, the load fluctuations has also been significantly inhibited.