Research And Application Of Load Reduction Control Technology For Flexible Tower Of Wind Turbine

With the low wind speed area development in China,the special turbine has become the trend of the future development of the wind turbine.One of the most important features of low wind turbines is the increase in the height of the tower.At present,the main tower tube technology is the full steel flexible tower,its low price,mature supply chain,convenient transportation and hoisting have been favored by the manufacturers.This paper takes a certain type of power unit as the research object,calculate the specific load reduction strategy for the wind turbine of tower.The vibration of the tower is caused by the rotation of the wheel.When the wind speed is below,analysis the resonant characteristics of the tower cylinder,combined with the operating characteristics of the wind turbine,the technology of load reduction for resonance crossing is put forward.When the speed of the wind wheel is at the edge of the zone,the PID control mode is adopted to control the torque of the generator to limit the speed.When the torque reaches a certain limit,the torque is released.The wind turbine passes through the resonance region quickly under the combined action of torque and wind speed to avoiding resonance.The independent variable propeller control strategy based on the variation of the blade root load is studied on the basis of the independent variable propeller theory of wind turbines at the rated wind speed.Through the Coleman coordinate transformation to the blade root load change as the hub fixed coordinates of the yaw moment and pitching moment,then using generalized regression neural network controller is transformed into the pitch transform,adjust the pitch angle in the transform amount is obtained after the inverse Coleman three pitch the.The control objective is to adjust the pitch angle in real time according to the variation of wind speed,so as to reduce the unbalanced load caused by tower shadow effect and wind shear on the wind turbine,and improve the stability and safety of the wind turbine.Finally,load calculation is carried out by GH Bladed software.By comparing the calculation results before and after adding control strategy of wind turbine,it verifies the effectiveness of the load reduction method described in this paper.