Every year, 25,000 new wind turbines are built worldwide, as the demand for this renewable energy source continues to increase. The answer from manufacturers and wind farm operators is the same in building larger and more powerful turbines. The control technology for limiting and optimizing output, however, has remained identical. At 170 m (about twice the height of the Statue of Liberty), the rotor diameters in offshore wind farms are now larger than some cathedral towers, and at the limit of what is technically feasible. On average, these huge wind turbines only achieve an efficiency of around 45 percent, and run at reduced capacity too often. When the wind load is too high, for example, it could damage he turbine. There are several companies that utilize both fiber optics measurement technology and AI (Artificial Intelligence) technology in their turbines, to increase efficiency.
Sensors in the Rotor Blade
The most important components in increasing the performance of a wind turbine in addition to the generator, are the rotor blades. Their direction of inflow, determines how efficiently the energy of the wind can be converted into electrical power. The wind direction and orientation (the pitch angle of the rotor blades) must be adjusted for the wind energy to be optimally used. Fiber-optic sensors inside the blades provide around-the-clock information about the physical properties of the rotor blade and the wind forces that strike it.
The Wavelength Displays the Force
For its measurements, some companies use industrialized edge filter systems in combination with fiber optic technology. When broadband light is fed into the fiber, a certain wavelength is reflected by the grating. The wavelength depends upon the effective refractive index of the fiber core and the grating constant. If one of these factors changes due to external influences such as temperature fluctuations or expansion of the fiber, the wavelength also changes. This principle can be used in various sensors to measure the acceleration or elongation of the rotor blades, to deduce the shear and torsional forces acting on the turbine at a given point in time. With little cost and effort, these sensors can be installed in existing turbines. In contrast to conventional electrical sensors, these specific sensors are insensitive to electromagnetic fields. This makes it possible to use the sensors at crucial measuring points in rotor blades, despite the danger of lightning strikes. Fiber optics applications are more powerful than electrical sensor components that cannot cope with enormous dynamic loads.
Intelligent Control Technology
Real added value is only created from the data recorded by the sensors through complex algorithms. This digital technology transforms the wind turbine into an intelligent power generator based on the measured data. For this purpose, an industrial PC, called thin-edge client, is in each turbine. In terms of Industry 4.0, the individual computers are linked to each other via the industrial internet of things (IIoT). The wind farm operator always has an overview of the output and operating status of each individual turbine, while keeping an eye on the values of the entire wind farm. Collected data is continuously recorded and evaluated using artificial intelligence. The analysis software is increasingly capable of aligning the rotors of the individual wind turbines in such a way that the entire wind farm always delivers optimum performance. It is believed that this is the best way to significantly increase efficiency within the wind energy industry.
At LASER COMPONENTS you can select the right fiber optics supported application in sensors, lasers, and spectrometers. Customers with UV and femtosecond lasers can inscribe their own gratings.
