###### Abstract
Therefore, reasonable dynamic analysis of wind turbine structure subjected to wind loads is an important guarantee to calculate the fatigue loads during normal operation. Although many researchers have made numerous contributions to the fatigue study of wind turbines [21; 22; 23; 24; 25], there are about 32 blade failures and 14 tower failures each year in the world, and the number is increasing over time [26]. For the safety of wind turbine structure, the safety of blades made in composite is becoming more important. And the considerably larger blades used in modern wind turbines has also made the safety of wind turbine more significant. It must be proved that the designed structure of wind turbine subjected to expected fatigue load is safety during service life. Hence, investigating the dynamic responses of large-scale wind turbine tower and blades during power production with BCS working is very important. Simulating the normal operation with BCS working is difficult for traditional FEM to investigate aeroelastic stability and structural dynamic responses of wind turbines. The computational procedures for wind turbine have increased in recent years. In the National Renewable Energy Laboratory (NREL), [PERSON] and [PERSON] [27] proposed an aeroelastic code FAST to predict the coupled dynamic responses of a wind turbine, which was applied to study scientific problems [28; 29; 30]. The techniques of multi-body system dynamics and modal analysis were used in the structural model. [PERSON] et al. [31] proposed the appropriate BCS for a 5-MW NREL wind turbine and the strategy of the BCS is always used in industry. As an open simulation platform, the dynamics responses of blades and tower with the BCS working can be obtained by adjusting the input files and modifying the program. As we all know that the BCS is an important part of a wind turbine and will affect the aerodynamic loads applied on the structure. What is more, fatigue analysis is based on the results of dynamic response. Studying the influence of the BCS on the dynamic and fatigue characteristics of modern wind turbines is significant, useful, and helpful for improving the design and manufacture of wind turbine support structures and blades. For modern large-scale wind turbines, the blade-pitch angle and rotor speed will change with different wind speeds according to the power control system during normal operation. Considering the BCS when calculating the dynamic responses of the tower and blades subjected to wind loads can obtain reasonable results, but it was always ignored in traditional research by using FEM. According to the aforementioned introduction, in this paper, the influence of the BCS on dynamic and fatigue characteristics of modern wind turbines was researched by comparing the dynamic responses of tower and blades with and without considering the BCS with wind speed from cut-in to cut-out. Using FAST, a 5-MW wind turbine under different wind scenarios is analyzed. The fatigue load expressed in damage equivalent load (DEL) was analyzed by using the algorithm of rainflow counting. The simulation results of dynamic and fatigue for two cases were compared. The research results are helpful and useful for the design of large-scale wind turbines.