基于集员未知输入观测器的风力机桨距执行器故障诊断

风力机一般放置在恶劣的环境中,其桨距执行器极易出现故障。文中针对一类含有未知但有界干扰和噪声的风力机系统的桨距执行器故障问题,设计了集员未知输入观测器对桨距的执行器故障进行检测并分离。采用气动机理和现代辨识原理建立风力机系统模型,通过优化未知输入观测器设计对系统中的干扰解耦,基于中心对称多胞体估计不考虑故障时残差的区间包络,并将其作为残差估计的上下动态阈值,实现状态估计。在上述基础上提出了利用一组集员未知输入观测器进行故障诊断的策略。仿真结果表明,在实验过程中,文中所设计的集员未知输入观测器准确地诊断出了风力机桨距执行器的3阶和5阶线性系统在发生突变故障和缓慢时变故障的时间和位置,证明了所提故障诊断策略的有效性。

Fault Diagnosis of Wind Turbine Pitch Actuator Based on Unknown Input Set-Membership Observer

Wind turbines are generally installed in harsh environments, and their pitch actuators are prone to failure. In view of the pitch actuator failure of a type of wind turbine system with unknown but bounded interference and noise, a collective unknown input observer is designed to detect and separate the pitch actuator failure. The model of wind turbine system is established by using aerodynamic mechanism and modern identification principle and the disturbance is decoupled by optimizing the design of unknown input observer. The interval envelope without considering the fault is obtained by zonotopes, which is used as the upper and lower dynamic threshold of the residual estimation to realize the state estimation. Based on the proposed design, a fault diagnosis strategy using a bank of unknown input observers is presented. The simulation shows that the time and location of the sudden and slow time-varying faults in the 3rd and 5th order linear systems of the pitch actuators are accurately diagnosed by the designed set unknown input observer, which verifies the effectiveness of the proposed fault diagnosis strategy.