On-Demand Night-Time Marking (ADLS) for Wind Turbines with Deutsche Windtechnik Control and WAGO

To reduce light pollution in the night sky, wind turbines in Germany will soon only illuminate when approached by aircraft. Deutsche Windtechnik Steuerung offers a solution for this “on-demand night-time marking (ADLS)” with a transponder-based ADLS system. The WAGO Relay, Item No. 857-304 is also used in this project.

Deutsche Windtechnik Steuerung, headquartered in Husum-Ostenfeld, has taken the leadership in wind farm maintenance. The company has maintenance contracts in Germany for around 2,400 turbines, with more worldwide. In addition to standard maintenance of land-based and offshore wind turbines, the team from Deutschen Windtechnik Steuerung conducts research into developing and expanding their services. In 2018, when a draft law for on-demand night-time marking (ADLS) of wind turbines was proposed, Deutschen Windtechnik Steuerung’s technicians and engineers began developing a solution to switch on the red flashing lights at the top of wind turbines, but only when they were needed. At that time, no finished industrial product could satisfy the legislators’ lofty safety requirements.

Merely switching the lights off is simply not a solution here, as the lights fulfill a necessary safety function: they warn any approaching aircraft about the wind turbines. Therefore, the solution must monitor the air space and emit a signal that allows the night-time marking to illuminate as soon as helicopters, airplanes, etc., approach within a radius of four kilometers. Wind turbine operators must legally implement ADLS on land by 31 December 2022 and at sea by 31 December 2023. The law applies to wind turbines starting at a height of 100 meters, meaning that most wind turbines in Germany are affected.

Communication between the boxes occurs via a local, proprietary wireless solution, developed by Deutsche Windtechnik Steuerung, which functions independently from other infrastructure, the wind farm boundaries and the system technology. A transponder receiver module monitors the air space and generates switching signals for illuminating the wind turbine. It detects aircraft within a distance of ten kilometers at an altitude of 600 meters or less. If aircraft comes within a radius of four kilometers around the wind farm, the module transmits a signal to the wind turbines, causing the marking lights to illuminate and flash red. Sixty-three slave boxes can be installed per transponder.

The transponder receiver transmits a signal to the ADLS Boxes every five milliseconds. If the boxes don’t receive any signal for 20 milliseconds, then the night-time marking lights turn on automatically for safety reasons. The same thing occurs if a fault occurs in the transponder box. In this case, the marking lights on all wind turbines connected to the transponder box will illuminate. If there is a fault in the ADLS Box, only the affected wind turbine lights up. The lights are, therefore, only switched off if everything is functioning perfectly and no aircraft is approaching.

Deutsche Windtechnik Steuerung continues to develop its ADLS Box, as some neighboring European countries – the Netherlands, Austria and France – are in talks about on-demand night-time marking. “Other countries have different standards and guidelines, naturally, so we have to stay on the ball,” explains Keusgen. In addition, a customer portal for operators of wind power systems is also under development.

WAGO and Deutsche Windtechnik Steuerung have worked in partnership for many years, so selecting WAGO relays to control the light signals was an obvious decision. “The design just confirmed it. Due to the clamping system, mounting is easy and fast, saving time and reducing costs. We are completely satisfied with the relays,” according to Keusgen. The uniform marking system on the relay modules also ensures a good overview. Once the electromechanical contact has reached the end of its lifespan, the pluggable elementary relay can be easily replaced during maintenance – without requiring intervention in the wiring – plug and play, as it were.

“We feel that we are well advised by WAGO, and our work dovetails nicely, Björn Ploog describes the interaction between WAGO and Deutsche Windtechnik Steuerung. In addition to the relays (Item No. 857-304), the company also uses the 2001 Series Rail-Mount Terminal Blocks in the very slender 4.2 mm version. Björn Ploog designed the DIN-rail with the rail-mount terminal blocks using the WAGO Configurator Smart Designer. He then received the DIN-rail with the rail-mount terminal blocks as fully configured components. For a renewed CE approval, Deutsche Windtechnik Steuerung is considering use of a WAGO Power Supply Unit, in addition to the relay (Item No. 857-304) and the 2001 Series Rail-Mount Terminal Blocks.