Extension of the DWM model towards a static model for site-specific load simulations

Abstract

The outlined analysis presents a method to extend the Dynamic Wake Meandering (DWM) model to allow a combination with load approximation methods, which are commonly used to estimate the loads during the planning process of a new wind farm layout. Determining a wind farm layout is a highly iterative process, where time-consuming calculations are avoided as much as possible. The DWM model is methodically designed such that it delivers an inhomogeneous wind field, which makes it useless for further application in load approximation tools that generally require a single value for the turbulence intensity. Furthermore, the DWM model is developed in a way that turbulent wind fields need to be generated to define the ambient turbulence as well as the meandering of the wind speed deficit itself. Likewise, this time-consuming process of calculating a turbulent wind field is in strong contrast with iterative wind farm layout optimization processes. Therefore, the developed extension of the model uses a probability density function to describe the meandering and requires no wind field simulations. The static DWM model is finally compared to the commonly used Frandsen turbulence model as well as to the original DWM model and produces less conservative fatigue loads than the Frandsen model.