Multi-innovation observer based fault detection for pitch system of wind turbines

Considering the pitch sensor fault of pitch systems in wind turbines, a multi-innovation observer based fault detection method is proposed. The pitch system can be modeled as a second order differential equation. And then the equation is transformed into a state space model. According to the state space model, a multi-innovation observer is designed to estimate the system state. The pitch sensor fault can be detected through the residual which is generated by comparing the state estimation with the output of an actual system. The simulation results show that the proposed approach is able to detect the pitch sensor fault effectively.