Use Case #1: “Apparent” change of Performance created by a faulty wind sensor
Vestas V90-3.0MW
1 - Turbine’s Performance Index started to deviate over time
2 - Wind speed prediction models detected a slow change on the wind speed measurement starting around the same date
3 - ExpertWind’s wind speed correction function explains most of the Power Curve change detected
4 - A residual underperformance (< 5%) remained after correction. This was found out to be related with a pitching issues on the turbine
Reliable Performance monitoring able to separate issues from the sensors and real underperformance on the wind turbines.
Vestas V90-3.0MW
1 - No YM was present during the initial period of the analysis
2 - A change appeared on the diagnosis time series: a significant YM was detected by the difference between the most frequent and best performing relative wind direction
3 - Issue corrected by the OEM. YM indicator went back to normal: the turbine is now well aligned with wind.
Reliable monitoring of YM on operating wind turbines over time. Estimated gain of 1.2% of AEP from the corrective action.
Use Case #2: Detection of Yaw Misalignment (YM) and corrective action performed by the OEM
Use Case #3: Detection of Nacelle Transfer Function (NTF) change
Senvion MM82-2.05MW
1 - ExpertWind’s prediction models detected a significant change (around 0.7 m/s) between wind speed predictions and measurements
2 - Measured Power Curve “shifted” to the right creating an apparent underperformance for the impacted turbine
3 - By applying the wind speed correction function, the change in performance disappears: it was only created from a change in the wind speed measurements
4 - OEM confirmed that an incorrect NTF was been applied and corrected the issue. Turbine PC and ExpertWind wind speed correction went back to normal after the correction
Performance monitoring not impacted by changes on the NTF and able to automatically detect the issue.
