On Condition Monitoring of Wind Turbines without Speed Sensor

We discuss implementation of wind turbine condition monitoring system (CMS) without speed sensor. The main method used is based on implementing Hilbert transform to extract the instantaneous frequency, where derivative of the analytic signal is done in the frequency domain. We analyze how to determine which vibration source, such as generator, gearbox high speed stage, or other turbine components should be used for speed extraction. The best choice of component is evaluated based on how good speed is estimated from various components in comparison to information from real speed sensor. Data from wind turbines collected over the years are used for statistical comparisons and selections of proper implementation. Information from estimated speed is then used along with an automatic diagnosis algorithm to detect different wind turbine faults.