Renewable Energy
Quality assurance of wind turbines using displacement sensors
The use of modern testing methods for wind turbines provides high quality and reliable operation. Erich Winkler reports.
El uso de modernos métodos de prueba para turbinas eólicas ofrece elevada calidad y fiabilidad. Informa Erich Winkler.
Dei Verwendung modernster Testmethoden für Windturbinen liefern hohe Qualität und zuverlässigen Betrieb. Erich Winkler Reports.
S
Fig. 1. Example of a wind turbine. Source: Bundesverband WindEnergie eV
ince the last amendment of EEG 2009, wind turbines have had an enormous market potential as the latest addition stipulates that electricity generation targets using
renewable energies will increase from 25 to 30 per cent. Te relatively new technology of modern systems still provides a lot of optimisation potential. Te use of modern testing methods provides high quality and reliable operation. Terefore, displacement sensors are being utilised more and more for the development, production and operation of wind turbines.
Te sensor system for controlling wind turbines is critical as the movement of the gondola and the rotors is performed automatically and must therefore be measured. Repair and maintenance work for land-based systems already have a high- risk potential. In the case of offshore systems, this high risk potential is also combined with enormous technical costs as special ships for complex tasks have long waiting times. Te latest sensors help to prevent breakdowns and optimise maintenance scheduling. Tis starts with the design of the components.
Rotors under load Torough test methods are increasingly required for the development of new geometries and production technologies for wind turbine rotors. Terefore, some test rigs have been developed for load testing of rotor blades, where actual loads caused by wind and weather conditions can be accurately simulated. It is important here that the expensive rotor is not destroyed during testing. Standard rotors are currently between 40m and 60m in length and are manufactured in a half shell sandwich arrangement made from glass fibre reinforced plastic. Te Fraunhofer Institut IWES, Bremerhaven
has developed a test rig that can be used to test rotor blades up to 70m in length. Te tip of the rotor blade can be distorted by up to 10m due to mechanical loads. For this, the rotor blade is mounted horizontally in the test rig. Steel cables are attached to the rotor using guide pulleys and connected to the rotor blade at various positions either directly or via mechanical clamps. Twelve draw-wire sensors are used on the test rig for measuring the distortion. Two sensors per traction point measure the deflection and torsion of the rotor blade. For this, the sensors are mounted on rails on the ground; the measuring wire is attached to prefabricated eyes on the terminals. Te simple handling and the robust design of the sensors are particularly impressive. Te draw-wire sensors in this application operate with measuring ranges between 3m and 10m. Te digital signal output is directly included for further simulations.
46
www.engineerlive.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68