Abstract: Methods and apparatus for control and monitoring of wind turbines. Various embodiments pertain to the operational analysis of vibratory modes of the blades of the wind turbine. This real time analysis of blade modal response can be used as feedback in a control system to change the yaw angle of the hub and nacelle to capture higher power from the wind stream, change the pitch on one or more blades to reduce uneven blade loading, to identify damage to a blade, and further to identify the accumulation of ice on a blade.

Abstract: In one embodiment, a method is provided for detecting a fault condition in a drivetrain, including the steps of monitoring torque oscillations at a location along a drivetrain, and detecting at least one fault condition associated with a drivetrain component by evaluating torque oscillation data acquired during the monitoring. In another embodiment, a system is provided for detecting a fault condition in a drivetrain including a torque sensor coupled to a drivetrain component and configured to measure torque at a location along the drivetrain and to generate a torque oscillation signal corresponding to the measured torque, and a controller configured to receive the torque oscillation signal and evaluate the torque oscillation signal to identify at least one fault condition associated with the drivetrain component.