Research On Control Strategy Of Large Wind Turbine

With world wind power industry explosive, especially in China where annual installed capacity is increasing at 100 percent rate, world wind turbine manufacture sized China market. At present, developing direction of wind turbine is large capacity, PMDD and offshore wind turbine. With the rapid development of electronic information industry, the control technology and remote monitoring technology of wind turbine is improving gradually. Now, the variable speed and pitch regulated control technology is applying to megawatt level wind turbine. This control method can capture the biggest wind energy, improve the power quality of grid connected effectively, and decrease the loads of drive chain and tower of wind turbine, which can prolong wind turbines'service life.Wind turbine is a multi input multi output system with high-order and nonlinear, and then considering random of wind, all of which make output power unstable. This paper gets the linear model the function of modal linearization of Bladed software. Then loading the linear model by MATLAB software to design wind turbine controller, which contains damping filter, torque controller and pitch controller. By setting the parameters of damping filter to reduce outside disturbance signal and oscillate of drive chain, thereby to reduce the loads of turbine; torque controller is activated between cut in wind speed and rated wind speed, by controlling the torque of generator to control speed of rotor and generator, which can achieve optimal blade top speed ratio operation; pitch controller is activated before cut in wind speed and after cut out wind speed, by regulating pitch angle can self-starting at low wind speed, and limit output power, then make output power constant. In the process of torque control and pitch control, adjusting PID parameters online to make the system's stability and rapidity better by applying RBF neural network.The purpose of wind turbine operating is capturing maximum wind power under the premise of safety and stable, by designing torque controller and pitch controller, and adjusting PID parameters to make the system control effect good; considering the natural frequency of blade, drive chain and tower, the damping filter in two controllers can reduce system loads and prolong turbine service life; ultimately, through comparative analysis, illustrating controllers are reasonable design and those meet control system requirement.