On the Fatigue Reduction of WTs via Coordinating Inertial Response and Pitch Angle Regulation

As one of the dominant renewable power generations, wind turbines (WTs) are expected to provide inertial response to contribute to power balance maintenance in modern power system. In practice, active power of variable-speed WTs can be regulated through expending inertial response signal and pitch angle control (PAC). For existing inertial control schemes, active power of WTs can be effectively smoothed when operating within the rated zone of rotor speed, while they will actually result in more considerable fatigue on the pitch servo system when rotor speed reaches the upper speed limit for high wind speed or maintaining relative low power reference inertially. To address this issue, a practical control scheme coordinating inertial response and pitch angle regulation is proposed in this paper. By differentially managing inertial response according to the rotor speed operation state and setting up threshold-limited returning rule for PAC, proposed scheme can effectively reduce pitch manipulation while sustaining desired inertial contribution. Simulation results show that this control scheme is highly effective and is easy to implement for application.