DYNAMIC RESPONSE AND RELIABILITY ANALYSIS OF WIND-EXCITED WIND TURBINE SYSTEMS

This paper explores the wind stochastic field of the wind turbine system from the viewpoint of stochastic function. Two kinds of Fourier spectra, the random Fourier spectrum and the rotational Fourier spectrum, are proposed based on the comprehension of the physical mechanism of the random excitations. The basic random parameters of the wind stochastic field, the roughness length and the mean wind velocity at 10m height, as well as their probability density functions (PDF), are obtained. It provides opportunities to use probability density evolution method (PDEM), which has been proved to be of high accuracy and efficiency, in computing the dynamic response and reliability of wind turbine systems subject to the wind loading. Principals of the PDEM are first presented. Then, the adopted model of the wind stochastic field is described briefly. The simulation method of the fluctuating wind velocity based on the two kinds of Fourier spectra is introduced. Finally, a 1.25MW wind turbine system subject to wind loading is investigated in detail. The responses, including the mean value and the standard deviation, and the reliabilities of the wind turbine system are evaluated by the PDEM. The results demonstrate that the PDEM is applicable and efficient in the dynamic response and reliability analysis of wind-excited wind turbine systems.