Measuring Natural Frequency In Large Wind Turbines
G-TECH Insights Newsletter: 2015-09-15
In this latest edition of the G-TECH Insights Newsletter, we look at Wilcoxon's handheld tri-frequency vibration calibrator: The Wilcoxon ReferenceMate. We also demonstrate how to measure the natural frequency of large wind turbines using OMA Technology.
Wilcoxon ReferenceMate - Handheld Tri-Frequency Vibration Calibrator
The Wilcoxon ReferenceMate is the industry's only handheld, tri-frequency output accelerometer calibrator that allows you to quickly verify the correctness of your accelerometer, signal line, and vibration measurement system in the field. It is equipped with a rugged rubber boot, making it ideal for use in harsh industrial environments. The internal shaker provides 1g rms or peak vibration and can be selected from three different frequency outputs—61.4Hz, 100Hz, and 159.2Hz—with a maximum load of 250 grams and 40 hours of continuous operation.
Measurement of the Natural Frequency of Large Wind Turbines Using OMA Technology
Our company was commissioned to perform structural modal analysis of the tower and blade of a wind turbine. For large structures like this, it is sometimes difficult to obtain good results with structural excitation using impact hammers. In this case, we can also consider the OMA (Operational Modal Analysis) method, which uses the random disturbance of wind forces in the natural environment to measure the natural frequency of the structure. In this case, we use the following equipment.
- 4-channel spectrum analyzer–Benstone Impaq Elite
- Impact hammer–Endevco Impulse Hammer
- High-sensitivity low-frequency accelerometer WR 799M
- Modal analysis software ME'Scope