From wind to the electric grid: Comprehensive modeling of wind turbine systems

A detailed model of a full-conversion wind turbine (WT) is presented in this article. The developed model uses cosimulation by several freeware WT simulation tools-such as the turbulent wind simulator (TurbSim) and Fatigue, Aerodynamics, Structures, and Turbulence (FA ST), both from the National Renewable Energy Laboratory (NREL)-and commercial software to perform a detailed analysis of all WT components. An optimal level of model complexity is achieved to allow the design, analysis, and simulation of the controls and subsystem interactions within a turbine under various conditions. The article introduces a maximum power point tracking (MPPT) control for a variable-speed WT with stall power regulation and analyzes its influence on flexible blades and the drivetrain. The proposed simulation tools and the developed model reveal some stability issues and subsystem interaction complexities that are not visible in simpler models. In this article, modeling results are presented that detail the performance of the WT system.