The Research Of Wind Turbine Reliability

As running in the complex environment, the wind turbine sometimes will be failure. This paper establishes a method for evaluating the wind turbine's reliability. The paper includes four parts: turbulence wind field model, the load of the wind turbine, the load distribution of wind turbine blade, the wind turbine reliability analysis.The section of turbulence wind field discusses the relations among the discrete random series ,the power spectrum and the Fourier spectrum in the random theory, introduces several representative and commonly used velocity power density spectrums such as Harris spectrum , Kaimal spectrum, Von Karman spectrum etc. Based on the random theory , an arithmetic programmed using MATLAB has been developed to calculate the turbulence wind velocities .In addition, this section introduces three factors which influence the steady wind velocity briefly, namely wind shean tower shadow, upwind turbine wake, so as to modify the wind field model.The section of the load of the wind turbine introduces the aerodynamic theories: the momentum theory, blade element theory, Strip theory. Giving a method to calculate the wind turbine's aerodynamic characteristic. Using the software Bladed For Windows to simulate the load of the blade in the turbulence wind field.The section of the load distribution of wind turbine blade discusses the statistical models of flapwise and edgewise blade-bending loads for fatigue. Distributions of rain-flow-counted range data for every ten-minute segment are characterized by parameters related to their first three statistical moments (mean value, coefficient of variation, and skewness). Three parameter Weibull distribution functions are based on these three moments. The long-term distribution of ranges is determined by integrating over the annual distribution of input conditions.The section of the wind turbine reliability analysis introduces the method for evaluation the reliability of the wind turbine blade against fatigue load and ultimate load in flap-wise bending. The first order reliability method is applied to perform a reliability analysis of the wind turbine blade.