Optimization, Dynamic Behavior And Fatigue Of Vertical-axis Wind Turbine

Many countries are facing the pressure of population, resource, environment with development of economy in 21 century. In order to resolve increasingly shortage of energy, the type of energy has been suffering the 3rd transformation. In the past, the mainly typical energy is coal, petroleum and gas. However the reproducible energy is developing quickly nowadays. Many countries dedicate the study of reproducible energy exploitation. Wind power is reproducible energy, which is likely to be an important substitute of energy in the future. Experts forecast that wind power would take up 10% of the all energy supplies in 21 century.Comparing with the horizontal axis wind turbine, the vertical axis wind turbine has many merits. First, design procedures are advanced, second, wind power utilization ratio is high, third, start wind speed is low, fourth, it has no noise etc. Therefore, the prospection application of VAWT is far-ranging.Based on the principal axis's characteristic of vertical axis wind turbine, the paper established the mathematical optimal model of the vertical axis wind turbine with the limit of static strength, stability and dimension constraints so as to light the structural weight and increase the natural frequency. The optimization was carried out in the ISIGHT environment.Based on the Tower structural design criterion, the paper analyzed the wind load acting on wind turbine, and established a finite element model of wind turbine, the stability is checked.The paper used modal analysis method to do the dynamical analysis on the vertical axis wind turbine, the turbine and blade's natural frequency was got with the Lanczos method. The paper also studied the natural frequency of the vertical-axis wind turbine at different rotate speeds, thus the Campbell diagram could be obtained to decide critical rotate speed of the wind turbine. The magnitude of critical rotate speed is one of standards which can estimate the safety of the rotating wind turbine.The cable is an important component of vertical-axis wind. The influence of cable parameters affected on the strength was studied, and the most suitable parameters of cables were determined.In the modern large-scale wind turbine design, the fatigue problem becomes more and more severely, the fatigue analysis method is discussed in the paper. Based on the Palmgren Miner linear fatigue damage accumulation method and the loading spectrum of the wind turbine, the blade's fatigue life was estimated.