Wind Turbine Independent Variable Pitch Power Regulation Issues Research

With the rapid development of economy, human's demand for energy isincreasing day by day. Because non-renewable resources of coal, oil and naturalgas continue to shrink, and developing and using clean energy, renewable energyhas become an imperative, thus the wind power industry is able to developmentquickly. Wind energy as a clean, renewable resource is more and more attentionin the word. Wind power has already been the composition of the nationalsustainable development strategy in many countries. Efficient and reliable windpower technology has become popular of the countries in the field of energytechnology, in which power conditioning is the key of wind turbine technology.Due to the instability and randomness of the wind, making full use of windenergy to get stable power output and achieve stable and efficient utilization ofwind energy, has a very important practical significance.Power regulation is one of the key technologies of the wind power. Windturbine is currently running on two power adjustment: one is fixed pitch stallcontrol; the other is the active pitch control. The active pitch control is dividedcollective pitch and individual pitch control. For the stability of the outputpower of the wind power generation system by the effects of wind velocityrandomness, on the basis of existing technologies, the design of wind turbineindividual pitch controller is improved. The design primarily considers the highwind speed stage active pitch control, and high wind speed stage individualpitch control is divided into two parts: First, based on novel nonlinear PIDcontrol, the design of collective coarse pitch controller make wind generator tobe able to get an output power curve, which is smooth and stable in the vicinityof the rated power; second, based on segment weighting coefficient assignmentof blade azimuth, the design of individual fine-tune pitch controller can reducethe blade loading caused by the effect of wind shear and the effect of towershadow, and extend the service life of wind turbines. Based on collective pitchcontrol, segment weighting coefficient assigns pitch angle changing uniformly, then we gain pitch angle changing alone in each blade of Wind turbine and takeindependent pitch control of wind turbine.Modeling in Matlab/simulink, the simulation results are analyzed. Thesimulation results show that the design of individual pitch controller can notonly get a stable power output, but also effectively reduce the wind turbine bladeloads, extending the service life of the wind turbines.