Modeling and Simulation Study of a DFIG Wind Turbine in a 3D Wind Field During Startup and Wind Speed Changes

An increasing amount of electrical energy worldwide is produced by renewable energy sources such as wind turbines. Modern wind turbines consist of multiple mechanical and electrical subsystems which influence each other during operation. In order to improve the wind turbine design, it is desirable to simulate its operating behavior under varying conditions using accurate simulation models. This paper aims to develop a simulation model for a doubly-fed induction generator wind turbine which considers the relevant characteristics of the many subsystems involved. In this model, the wind rotor blades, mechanical drive train, generator system, and the surrounding wind field are represented and modeled in sufficient complexity. In a multi-rate simulation, the model is verified using a machine startup scenario as well as a wind gust scenario. The simulation results show the interaction between the wind rotor, drive train, and generator system. During wind speed changes, the generated power fluctuates before reaching a new steady-state condition. Oscillations occurring in the drive train put stress on the mechanical parts of the wind turbine and influence the power, transmitted to the point of common coupling.