Lidar-assisted control using preview wind information has become an important research topic in the wind turbine control community, and several lidar manufacturers offer forward-staring nacelle lidars that can be used for control purposes.
The use of lidar-assisted control is currently limited to a few research turbines, but results are promising. For example, during initial field testing collective pitch feedforward controllers have been able to successfully improve rotor speed regulation, reduce fatigue loads, and decrease pitch actuator activity. Additionally, numerous control studies relying on simulation are paving the way for more advanced lidar-assisted controllers.
One obstacle to the widespread adoption of lidar-assisted control, however, is its multi- and interdisciplinary character. A thorough understanding of lidar measurement principles and limitations (e.g., reliability, accuracy, scan pattern capabilities, etc.) is mandatory for designing a control system. Also, knowledge about wind turbine dynamics and controls is necessary to determine what types of lidar signals are useful for control and what lidar system properties are required. Since lidar and turbine manufacturers typically specialize in their own part of the puzzle, current lidar systems are not necessarily optimized for wind turbine control applications.
The purpose of this workshop was to bridge the gap between lidar manufacturers and wind turbine control engineers by
- identifying the objectives of lidar-assisted control,
- identify barriers preventing the widespread use of lidars for control,
- design suggestions for overcoming those barriers,
- and identify additional design considerations for maximizing the effectiveness of lidars for control purposes.