System and method for detecting and responding to rotor blade damage in a wind turbine

A wind turbine, comprising:

• a tower;
• a nacelle mounted atop the tower;
• a rotor comprising a rotatable hub and at least one rotor blade communicatively coupled with a pitch system;
• and
• a controller configured to perform a plurality of operations for controlling the wind turbine, the plurality of operations comprising:
• monitoring at least one signal of a pitch actuator of a pitch system of the rotor blade of the wind turbine during a certain time period, the at least one signal being a proxy for a pitch driving torque of the pitch actuator of the pitch system;
• defining a time-domain metric that captures certain behavior of the proxy for the pitch driving torque of the pitch actuator of the pitch system, wherein the certain behavior of the proxy for the pitch driving torque of the pitch actuator of the pitch system comprises at least a rate of change of the proxy for the pitch drive torque;
• comparing the time-domain metric to a corresponding time-domain metric associated with a reference rotor blade representing a healthy rotor blade, the corresponding time-domain metric also being collected during the certain time period;
• and
• implementing a control action when the time-domain metric is outside of a predetermined range defined by the healthy rotor blade.