Lidar-assisted control for wind turbines

Sowento provides tools to reduce loads and improve performance of wind turbines using nacelle-based lidar systems. The spin-off from the University of Stuttgart works with lidar and turbine manufacturers to transfer innovations from research to industry. Sowento offers you expert knowledge, a five-year-history of field tests, and our passion for control theory to bridge the gap between commercial lidar systems and industrial turbine controllers. Read more about why and how the company aims to push lidar-assisted control into a wide-spread industrial application.

The Opportunity

How much can you increase the annual energy production of wind turbines using a lidar? We have developed tools and gathered experience to apply lidar-assisted control strategies to provide a good estimate for the benefit of lidar-assisted control for specific turbine types and site conditions.

The following gives you some insights into the typical lidar-assisted control projects which we perform together with our partners.

The application process in lidar-assisted control that shifts the focus from academic investigation (rotor speed regulation) to an industrial application (structural load reduction, increased energy production).

In research and first field tests, the performance of lidar-assisted control has been mostly assessed with the improvement of rotor speed regulation since this is the primary control goal. However, for wind turbine manufacturer this is a secondary goal as long as the rotor speed stays within its design margins. In reality, the increase of energy yield and the reduction of structural loads are the important measures for controller performance.

The Implementation

Lidar-assisted control is a multidisciplinary technology and roughly can be divided in lidar data processing and controller design: While the lidar data processing is responsible to provide useful signals, the controller design aims to make use of these signals.

The basic control loop of lidar-assisted control for wind turbines.

Lidar data processing

Current commercial lidar systems usually don’t provide signals which can be directly used for control. Since the lidar technology only provides limited information of the wind and the wind also evolves on its way towards the turbine, special lidar data processing techniques such as wind field reconstruction, filter design and synchronization need to be applied. Sowento not only provides these techniques, but also helps lidar manufacturer to adjust their system, e.g. the scan configuration, to provide the sophisticated signals for control.

Controller design

Achieving the desired performance, e.g. reduction in structural loads, the controller design needs to be adapted by considering the additional support of the lidar feedforward controller. This procedure is also known as two-degree-of-freedom controller design: While the lidar-assisted feedforward controller (FF) is responsible to compensate the dynamic effects of changes in the wind measured by a lidar system, the feedback controller (FB) compensates the remaining effects based on the turbine’s reaction. By the use of controller design models the feedback controller is retuned to achieve the desired performance. Sowento has the tools to perform simulation studies and data analysis to optimize your control system.

Your choice

Get in contact with us to assess the performance improvements of your wind turbines by nacelle-based lidar systems and make yourself ready for the next generation of lidar-assisted control of wind turbines.

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