System and method for monitoring vibrations in a drivetrain of a wind turbine

A drivetrain assembly of a wind turbine, the drivetrain assembly comprising:

• a rotor shaft for coupling to a rotor of the wind turbine;
• a gearbox coupled to the rotor shaft;
• a generator coupled to the gearbox via a generator shaft;
• and
• a controller for controlling operation of the wind turbine, the controller comprises at least one processor, the at least one processor configured to perform a plurality of operations, the plurality of operations comprising:
• receiving a first rotational speed signal at a first location along the drivetrain, the first rotational speed signal being a proxy for rotor speed of the rotor;
• receiving a second rotational speed signal at a second location along the drivetrain, the second location being downwind from the first location, the second rotational speed signal being a proxy for generator speed of the generator;
• determining a speed error based on a comparison of the first and second rotational speed signals;
• determining a torque deviation signal for the wind turbine configured to dampen drivetrain vibrations when the speed error exceeds a first speed threshold;
• and
• applying the torque deviation signal to the generator to dampen the drivetrain vibrations by reducing the speed error.