Research On The Technology Of Pitch-control For MW-classic Wind Turbine

At present, our country strives to develop the renewable energy sources for the sustainabledevelopment because of the severe environmental problems occasioned by burning fossil energy.Wind energy source is a kind of energy which is inexhaustible inexhaustible and green.That’s whywind energy get the favour of people. The wind power industry of China has also been a rapiddevelopment. Wind power technologys is the core of wind power industry. Based on the domesticmegawatt wind tubines HTWY-1500, the pitch control techniques for MW-classic wind turbine aredeeply analyzed in this thesis.Firstly, lauching on the basic theory of wind turbine blade aerodynamics, this thesis introduce thefundamental of pitch control and model the wind and every part of the wind turbine by Matlab.Secondly, in view of the characieristics of the nonlinear of the power control to the pitch angle,this thesis brings forward with a strategy of linear gain scheduled. The strategy provides an updatemechanism of which update the gain of the PI controllers according the pitch angle, with which canstabilize the output power.The results prove that the strategy of linear gain scheduled are better thantraditional PID by simulation.It has less power overshoot and stronger robustness.And then, for reduceing the unbalance load, this thesis use two strategys of individual pitchcontrol to solve the problem, which one is azimuth feedback, another is load feedback. This thesisananlyse the influence of wind sheer and tower shadow on the power control, prove the disadvantageof power control and the load of the blade with only collective pitch control by simulation. Thestrategy of azimuth feedback changes the pitch angle according to the wind estimate by the azimuthangle. The strategy of load feedback change the pitch angle in real time by the D-value between theload of the blade and which of the average calculation model.It is proved that two strategy can alsoreduce the unbalance load effectly by simulation,but load feedback is better.Because it is greater inreduceing the pitch load and the yaw load.Lastly, this thesis redacet the dll peripheral controllers, and simulate by bladed.The results provethe strategy in this thesis can meet control requirement, the theory and the simulation research is rightand reasible.