风力机桨距执行器LPV容错控制器设计

Linear Parameter Varying Fault Tolerant Controller Design for the Pitch Actuator of Wind Turbines

为了解决桨距执行器故障导致的桨距角动态变慢和输出功率波动的问题,结合最小二乘估计算法,提出了线性变参数（LinearParameterVarying,LPV）容错控制器设计方法。采用欧拉变换将二阶传递函数转化为辨识方程,利用最小二乘辨识算法估计桨距系统中的自然频率和阻尼系数,进而得到故障指示因子。选取风速和故障指示因子作为调度变量,得到包含故障的风力机LPV模型。根据凸分解技术,将求解无穷多个线性矩阵不等式的问题转化为求解有限个不等式的问题。并且利用LMI工具求解线性矩阵不等式得到LPV容错控制器。最后,选取液压空气含量过高故障验证算法的有效性。

The dynamic response of the pitch angle will be slowed down when the pitch actuator of wind turbines fails and the fault will lead to the output power fluctuations. In order to solve the problem, a linear parameter varying（LPV） fault tolerant controller design method combined with the least squares estimation algorithm is proposed. The second order transfer function is transformed into the identification equation by using the Euler transformation. Next, the time varying natural frequency and damping ratio of pitch actuators are estimated using the least squares estimation algorithm. Then, the fault indicator factor can be obtained accordingly. The LPV model including faults of wind turbines is established by choosing the wind speed and fault indicator factor as scheduling variables. According to the convex decomposition technique, an infinite number of linear matrix inequalities（LMIs） are transformed into a finite number of LMIs, and the LPV fault tolerant controller is obtained by solving the LMIs using the LMI technology. Finally, the feasibility of the algorithm is validated by choosing the fault of high air content in hydraulic oil.