Low yaw reactivity affecting power curve performance
Problem
1
The client has an undiagnosed underperformance issue on one of his wind farms.
Windfit Findings
2
Windfit is installed to diagnose the cause of this underperformance.
Windfit identifies the turbines to have a very poor yaw reactivity: 17.6° yaw movement amplitude for 2.3 movements per hour.
Solution
3
A change in the controller software is then implemented on one of the turbines (turbine 13).
Results
4
This software change significantly improves the turbine reactivity: 9.5° amplitude for an average of 5.3 movements per hour, gaining a solid 1% AEP in the process.
Correcting north deviation to optimize curtailment strategy
1
Windfit is installed on a turbine close to a village. The turbine suffers important AEP losses due to severe sound management at night.
2
Since installation Windfit has detected a significant North Deviation of up to 50°, meaning that the turbine shuts down on the incorrect sectors.
3
A correction on site is carried out to re-configure the turbine to the True North as measured by Windfit.
4
The turbine operates now with the right parameters to reduce sound emissions and optimise production.
+6.5% AEP gain after rotor imbalance correction
1
Windfit detects an aerodynamic rotor imbalance.
3 months later
2
Gamesa confirms the diagnosis and corrects a 4° blade pitch offset.
3 weeks later
3
Windfit measures a gain of +6.5% AEP.
Windfit detects production drop caused by onsite maintenance
1
A large IPP uses Windfit as part of their windturbine maintenance routine to make sure no under-performance goes undetected after on-site activities.
2
A few weeks after installing Windfit, a very high rotor aerodynamic imbalance is detected. The user is alerted, the AEP loss could be as high as 4%!
3
A team is sent on site, finds one of the blades had been misaligned by more than 1.5° during a turbine maintenance activity, and corrects the issue.
4
Thanks to Windfit permanent watch and our client's quick reaction, the turbine is now optimised and ready to perform at its best during the windy winter period to come.
+12° yaw misalignment corrected & 4% AEP gained
1
Important +12° YAW misalignment detected by Windfit
After LIDAR campaign
2
Windfit diagnosis confirmed with coherent & similar results
1st corrective action applied
3
Windfit detects that on-site correction has been applied on the wrong direction... aggravating the YAW misalignment!
Back to normal
4
4% AEP gain. Performance increased after correction. Windfit kept permanently on turbine to ensure turbine optimization.
Rotor mass imbalance correction
1
Windfit detects a high mass imbalance upon installation.
2
Our client is alerted and calls Cp.max to balance the rotor.
3
A total of 275 kg weights is added to the blades, significantly decreasing the rotor mass imbalance.
1.5% AEP loss detected and corrected in two days
1
Windfit detects a rotor imbalance and alerts the operator.
February 4th
2
The asset manager calls Enercon.
February 5th
3
The O&M team goes on site and confirms a pitch offset between the three blades.
4
The O&M team immediately corrects the issue.
Static yaw misalignment detection and correction
1
Windfit detects a significant and stable static yaw misalignment.
2
A LIDAR campaign on site confirms the yaw misalignment diagnosed by Windfit.
3
A yaw angle correction of -5.3° is applied to the turbine’s controller, leading to 2.3% immediate AEP gain.
Aerodynamic imbalance impacts on wind turbine performance
May, 11th
1
Windfit detects an increase of the aerodynamic imbalance.
Shortly after
2
Sereema's expert team confirms a significant decrease of the wind turbine performance.
3
The O&M checks the zero angle of the blades and corrects a 3° pitch offset on one of them, which leads to a 6.5% AEP gain.
A reactive alert system saving clients time and money
1
Windfit is permanently installed on a turbine to monitor its overall performance.
Some months later
2
Following a maintenance activity, Windfit detects a severe aerodynamic imbalance.
Minutes later
3
The customer receives a Windfit alert and a site visit is scheduled.
A week later
4
A 2° blade misalignment is corrected, avoiding a 4% AEP loss that would otherwise have taken months to detect.
Detection and correction of an important blade misalignment
1
Windfit identifies an important Rotor Aerodynamic Imbalance on turbine 6, whereas all other turbines show low levels.
Plan of action
2
Sereema's technical support team discusses with the wind farm owner the best plan of action to correct this issue.
Pitch angle realignment
3
The blade pitch angles are checked via laser measurements.
Important pitch angle offsets of +0.6° & -0.7° are detected and corrected on 2 blades, reducing the rotor imbalance and vibration levels.
