风电机组的积分模糊滑模变桨距控制

Integral fuzzy sliding-mode control for variable pitch of wind turbine generator system

针对变桨距风力发电机组具有参数变化、强干扰、建模困难等特性,设计出了一种积分模糊滑模变桨距控制器。通过在传统滑模控制器中采用状态变量代替误差项的导数并引入误差项的积分来设计切换函数,消除了传统变结构控制需要已知期望输出信号导数的假设;利用模糊推理动态地调节切换增益,并采用积分的方法对切换增益上界进行估计,避免了传统滑模控制器需要选取不确定因素上界,同时采用合适的连续函数来代替切换增益中的符号函数,有效地削弱了系统的抖振。仿真结果表明:该控制器应用在风速高于额定风速以上的变桨距控制系统中,对系统参数的不确定性和外部干扰均具有很强的鲁棒性,能够有效地改善风电机组变桨距系统的控制性能。

Considering the characteristics of wind turbine generator system with variable pitch propeller including uncertain pa- rameters, strong disturbance and difficult modeling, an integral fuzzy sliding - mode controller was designed for variable pitch. The switch function was designed by the integral error and state variables that replace the derivative of error, which overturned the hypothesis that the derivative of desired output signal must be known in traditional sliding mode control. The switching gain was dynamically adjusted by fuzzy logical reasoning method and its upper bound was effectively estimated by using integral method to dispense with the selection of upper bound of uncertain parameters in traditional sliding mode control. The sign function of the switching gain was replaced by a suitable continuous function and the system chattering was effectively reduced. The simulation results show that the controller, to be used in the variable pitch control system when the wind speed is higher than the rated wind speed, has strong robustness and is able to effectively improve the control performance.