Damaged blades

[Wim Dijkman]

Hello,

My name is Wim Dijkman and work for an company in Taiwan.
I repair rotor blades for more than 30 years now,but I can not find an answer for this problem.
We have 14 Z72 turbines near the coast of Taiwan.
Last week we had an average wind speed of 22m/s with gust winds from 31m/s.
Now there is just 1 tower with an higher vibration than the other 13 turbines.
That turbine also has 3 broken with broken trailing edges now and the blades at the other 13 turbines are just fine.
Before that turbine had also some problems and now they installed an new tower and 3 new blades.
The older turbines are all fine, it is just that specific turbine.
Why is it just only this specific turbine ?
The settings are all the same as the other turbines.
There is an wall from stones about 1 meter high which changes into an fence from 1 meter high along the coastline.
I was thinking that it could cause centrifugal loads under the tip of the blade, but I think that these loads can not cause high tower vibration and 3 damaged blades.
What other reason can there be ?

Thanks in advance,
W.Dijkman

[Sune in Denmark]

Depending on age of wind turbine, it is not unlikely to have a digital vibration monitor inside for monitoring of tower vibration. In many cases these are supplied by PCH Engineering. If this is the case, it may be possible to add data-logging to the affected turbine as well as one of the other turbines, and then see if this gives a hint about challenge at hand. ( [Admin: Self-serving link removed] )