Estimation of Effective Wind Speed for Fixed-Speed Wind Turbines Based on Frequency Domain Data Fusion

The rotator of the wind turbine is subject to a spatially and temporally distributed wind field; the wind speed varies significantly at different points over the blades plane. This makes a direct measurement of effective wind speed impossible. We analyze the spectrums of the measurement of the anemometer and generator power of a wind turbine, and point out that the characteristics of these two signals are complementary in the frequency domain. Then an observer for effective wind speed is proposed based on frequency-domain data fusion. The observer design is formulated as a mixed-sensitivity problem with linear matrix inequalities (LMIs). Simulations were carried out to assess the performance under a realistic wind speed profile. The simulation results show that the observer can not only guarantee the static accuracy, but also improve the dynamic accuracy of the measurements of the effective wind.