Wind turbine main-bearing loading and wind field characteristics

This paper investigates the relationship between wind turbine main-bearing loads and the characteristics of the incident wind field in which the wind turbine is operating. For a 2-MW wind turbine model, fully aeroelastic multibody simulations are performed in 3D turbulent wind fields across the wind turbine's operational envelope. Hub loads are extracted and then injected into simplified drivetrain models of three types of main-bearing configuration. The main-bearing reaction loads and load ratios from the simplified model are presented and analysed. Results indicate that there is a strong link between wind field characteristics and the loading experienced by the main bearing(s), with the different bearing configurations displaying very different loading behaviours. Main-bearing failure rates determined from operational data for two drivetrain configurations are also presented.