Detecting faults in wind turbines

A controller configured to detect wind turbine generator faults having a processor programmed to:

• receive real-time operating current data from a wind turbine generator during operation of the wind turbine generator, the current data being sampled at a first sampling frequency;
• determine a frequency demodulated signal and an amplitude demodulated signal by frequency demodulating and amplitude demodulating the current data;
• estimate a shaft rotating frequency of the wind turbine generator based on the frequency demodulated signal corresponding to the current data;
• resample the frequency demodulated signal and amplitude demodulated signal of the current data based on the estimated shaft rotating frequency of the wind turbine generator and using a second, different sampling frequency;
• calculate respective frequency spectra of the resampled frequency demodulated signal and amplitude demodulated signal corresponding to the current data;
• and
• extract one or more impulses in the frequency spectra to detect wind turbine generator faults in a frequency domain.

A system for monitoring current to predict wind turbine generate faults comprising:

• a current sensor configured to acquire current data from an operating wind turbine generator;
• and
• a processor connected to receive the current data from the current sensor, the processor programmed to:
• receive, from the current sensor, current data from a wind turbine generator during operation of the wind turbine generator, the current data being sampled at a first sampling frequency;
• determine a frequency demodulated signal and an amplitude demodulated signal by frequency demodulating and amplitude demodulating the current data;
• resample the frequency demodulated signal and amplitude demodulated signal corresponding to the current data using a second, different sampling frequency in order to convert a variable 1 P frequency of the wind turbine to a constant value;
• monitoring respective frequency spectra of the resampled frequency demodulated signal and amplitude demodulated signal corresponding to the current data to identify excitations in the frequency spectra;
• and
• in response to identifying an excitation in the frequency spectra at a frequency that is characteristic of a wind turbine generator fault, generating and transmitting an alert that indicates that a wind turbine generator fault is detected.