A Frequency Domain Approach to Wind Turbines for Flicker Analysis

Wind turbines may have an important impact on power quality. Flicker is a more serious issue for fixed-speed wind turbines, because these turbines produce electric power following the variations of the incident wind. During continuous operation, wind variations will result in power fluctuations and consequently in voltage fluctuations. It is necessary to evaluate wind turbine flicker emission level, and traditionally time domain simulations have been used to perform the analysis. This paper presents a complete frequency domain model to study flicker produced during wind turbine continuous operation. The model includes a realistic wind speed model as observed by the wind turbine, and also a frequency domain induction generator model is presented. The frequency domain model is compared with a time domain model. The frequency domain approach, as shown in the paper, may be very useful for flicker analysis in electric networks.