Wind Energy

29
Online Modeling of Wind Farm Power
for Performance Surveillance and Optimization
J.J. Trujillo, A. Wessel, I. Waldl and B. Lange
Summary. From practical experience it is known that many reasons for an unsatisfying
energy yield of wind farms occur. Particular issues are difficult to discern due
to the interaction of the turbines through wake effects. Therefore, reliable wind farm
modeling is necessary in order to assess faulty operation and energy production of
single turbines. In this paper a method to obtain the expected performance for
each single turbine in a wind farm in online basis is presented and tested with real
measured data.
29.1 Wind Turbine Power Modeling Approach
Our approach to the single turbine power performance assessment of single
turbines is to extend a wind farm model in order to make it work with quasireal
time data. Time series of operational data of a wind farm are fed to
the model which calculates average power delivered by each single turbine.
The modeled power is compared afterward to the measured power data. The
wind farm model will be integrated into the wind farm management system
OptiFarm TM [1] for wind turbine surveillance purposes.
29.1.1 Wind Farm Model
The selected wind farm model is the farm layout programm (FLaP), an
advanced model developed at Oldenburg University [3, 6]. The model manages
the superposition of wakes and other relevant wind farm effects to predict
an effective wind speed at hub height of each turbine. Finally, the power
produced by the turbine is calculated with the power curve of the turbine
and the modeled effective wind speed. Extended versions of two wake models,
namely Ainslie [2] and Jensen [5] model, have been implemented in FLaP for
single wake calculation.