Research And Application Of Variable Pitch Control Technology For Direct-driven Permanent Magnet Synchronous Wind Power System

Because of the elimination of a gear box, the direct drive permanent magnet synchronouswind turbine, not only improving the stability and reliability of the system, reducing the unitpost-maintenance and cost, but also with the advantages of high efficiency and adaptable tothe grid exception, which becomes the research focus of the current domestic and foreignexperts and scholars. With the increasing unit capacity of the wind turbine, pitch controlsystem plays an increasingly important role in safe, stable and efficient operation of windturbine generator, so the exploration and research of the superior pitch control algorithm forwind turbine has become one of the research priorities of the wind turbine control technology.To direct-drive permanent magnet synchronous wind power system as the researchobject, on the basis of mastering the basic theory of wind power generation, apply themechanism analysis to establish the mathematical model of the direct drive permanent magnetsynchronous wind turbine, and build the simulation model of the whole wind turbine usingthe MATLAB simulation tool. For the wind speed below the rated wind speed, it had studiedmaximum wind energy capture method based on interference feedforward compensation,which had achieved maximum wind energy capture in low wind speed. When the wind speedis above rated wind speed, taking the features of nonlinearity and moment of inertia of thewind turbine into account, the traditional PID control algorithm and fuzzy control algorithmcan not achieve the desired control effect. According to the wind turbine aerodynamic torqueon the sensitivity of the pitch angle, this paper has increased a fuzzy feedforward controller tocompensate for the pitch angle based on fuzzy adaptive PID controller, in order to solve theproblem of wind turbine pitch control difficulties. Finally, compare the control performanceof the three controllers by simulation, it can be obtained: fuzzy adaptive PID and fuzzyfeedforward combined control algorithm has better stability and dynamic characteristics thanthe fuzzy control algorithm and the traditional PID control algorithm, and has provided thereference and basis for further research on wind turbine control technology.