System and method for slip detection and surface health monitoring in a slip coupling of a rotary shaft

A method for operating a generator of a wind turbine, the wind turbine having a hub rotatably coupled to the generator via a rotor shaft that rotatably drives a gearbox that subsequently drives a generator shaft having a slip coupling, the method comprising:

• generating, via a controller, a time series of a plurality of operating signals of the generator;
• applying at least one algorithm to the time series of the plurality of operating signals of the generator to generate a processed time series of the plurality of operating signals of the generator;
• identifying, via the controller, patterns in the processed time series of the plurality of operating signals of the generator to estimate torque information relating to the generator shaft;
• predicting a start of a slip event occurring in the slip coupling using the torque information relating to the generator shaft;
• and
• controlling a power converter of the wind turbine to mitigate the slip event;
• wherein the plurality of operating signals comprise at least one of a generator speed, a rotor speed, a generator current, or a generator voltage:
• estimating an electromagnetic torque of the generator as a function of the generator current and the generator voltage;
• estimating a shaft torque of the generator using the electromagnetic torque of the generator and the generator speed;
• and estimating a coupling torque of the generator using the shaft torque, and
• wherein applying the at least one algorithm to the time series of the plurality of operating signals of the generator to generate the processed time series of the plurality of operating signals of the generator further comprises estimating a first derivative of a shaft torque of the generator.

A system for operating a generator of a wind turbine, the wind turbine having a hub rotatably coupled to the generator via a rotor shaft that rotatably drives a gearbox that subsequently drives a generator shaft having a slip coupling, the system comprising:

• a controller comprising at least one processor, the at least one processor configured to implement a plurality of operations, the plurality of operations comprising:
• generating a time series of a plurality of operating signals of the generator, the plurality of operating signals comprising at least one of generator speed, rotor speed, generator current, or generator voltage;
• applying at least one algorithm to the time series of the plurality of operating signals of the generator to generate a processed time series of the plurality of operating signals of the generator, wherein applying the at least one algorithm to the time series of the plurality of operating signals of the generator further comprises estimating an electromagnetic torque of the generator as a function of the generator current and the generator voltage, estimating the shaft torque of the generator using the electromagnetic torque of the generator and the generator speed, and estimating a coupling torque of the generator using the shaft torque;
• identifying patterns in the processed time series of the plurality of operating signals of the generator to identify a start of at least one slip event occurring in the slip coupling or surface health degradation of the slip coupling;
• and
• implementing a control action when the at least one slip event occurring in the slip coupling is identified or the surface health of the slip coupling is indicative of degradation in the slip coupling,
• wherein applying the at least one algorithm to the time series of the plurality of operating signals of the generator to generate the processed time series of the plurality of operating signals of the generator further comprises at least one of estimating a first derivative of the shaft torque of the generator or determining a second derivative of the generator speed.