Wind turbine with rotor blade problems? Rapid help is needed!
The run-up: With the help of a crane a new rotor blade had been installed on the rotor of a damaged turbine, but after the restart, the system suffered from extremely high vibration levels. As rotor imbalances are not uncommon following blade repairs or replacements though, the on-site service team reacted quickly and informed our team of engineers. Greenwind immediately initiated a measurement campaign on behalf of the operator.
The procedure: As per standard, we initially checked the aerodynamically induced rotor imbalance (blade angle error) and then determined the remaining mass-induced rotor imbalance. The blade angle measurement revealed a blade angle error of 6°, which corresponds to almost one bolt spacing (see figure). It was thus reasonable to assume that the blade, during installation, had been installed offset by one bolt. This meant that the replaced blade was exposed to a completely different flow than the other two blades, causing high vibrations in the entire tower-nacelle system.
The result: We were able to correct the 6° without having to remove the blade again with a crane, and the successful modification of the blade angle was verified shortly afterwards by a new measurement. The system is now up-and-running smoothly, and once again sustainably producing green electricity. The costs that would have been incurred in the long term due to extensive repair work were in this way reduced to a minimum.
