Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

“Anti-noise” silences wind turbines

13.08.2008
If wind turbines clatter and whistle too loudly, they are only permitted to operate under partial load to protect the local residents – but this also means a lower electricity output. An active damping system cancels out the noise by producing counter-vibrations.

If wind energy converters are located anywhere near a residential area, they must never become too noisy even in high winds. Most such power units try to go easy on their neighbors’ ears, but even the most careful design cannot prevent noise from arising at times: One source is the motion of the rotor blades, another is the cogwheels that produce vibrations in the gearbox.

These are relayed to the tower of the wind turbine, where they are emitted across a wide area – and what the residents hear is a humming noise. “People find these monotone sounds particularly unpleasant, rather like the whining of a mosquito,” says André Illgen, a research associate at the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Dresden. If the wind energy converters hum too loudly, they are only permitted to operate under partial load: They rotate at a slower speed and generate less electricity.

In some cases the operators have to install additional damping systems or even replace the gearbox – an expensive business. However, the effectiveness of the passive damping systems used until now is somewhat limited: They only absorb noise at a certain frequency. Since modern wind energy converters adapt their rotational speed to the wind velocity in order to generate as much electricity as possible, however, the frequency of the humming sound also varies. Despite noise attenuation measures, humming noises penetrate the surrounding area.

In a joint project with colleagues from Schirmer GmbH, ESM Energie- and Schwingungstechnik Mitsch GmbH and the Dr. Ziegler engineering office, IWU researchers have developed an active damping system for wind turbines. The project is being funded by the “Deutsche Bundesstiftung Umwelt”. “These systems react autonomously to any change in frequency and damp the noise – regardless of how fast the wind generator is turning,” says Illgen.

The key components of this system are piezo actuators. These devices convert electric current into mechanical motion and generate “negative vibrations”, or a kind of anti-noise that precisely counteracts the vibrations of the wind turbine and cancels them out. The piezo actuators are mounted on the gearbox bearings that connect the gearbox to the pylon. But how do these piezo actuators adjust themselves to the respective noise frequencies? “We have integrated sensors into the system. They constantly measure the vibrations arising in the gearbox, and pass on the results to the actuator control system,” says Illgen.

The researchers have already developed a working model of the active vibration dampers, and their next step will be to perform field trials.

Monika Weiner | alfa
Further information:
http://www.fraunhofer.de
http://www.fraunhofer.de/EN/press/pi/2008/08/ResearchNews082008Topic3.jsp
http://www.fraunhofer.de/EN/bigimg/2008/rn08fo3g.jsp

Further reports about: cogwheels counter-vibrations damping system rotor blades wind turbines

More articles from Power and Electrical Engineering:

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

nachricht TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>