Wind turbine balancing system

While a rotor balance quality standard has not been adopted by the wind turbine industry, an ISO G16 or better may prove to be a practical and acceptable target. G0.4 is achievable with tight blade manufacturing tolerances and/or dynamic field balancing.

Wind turbines are highly engineered mechanical devices designed to have balanced rotors. Unacceptable levels of rotor unbalance accelerate mechanical fatigue on everything connected to it — bearings, shafts, pitch systems, gearboxes, generators, yaw drives, towers, and even foundations.

It is shown that a combination of blade and nacelle measurements, most of which can be obtained from standard instrumentation already found on utility-scale wind turbines, can be formulated into an algorithm used to detect and locate imbalance.

Figure An unbalanced wind turbine rotor results from a mismatched weight distribution of the individual blades that make up the rotor. There may be several consequences of an unbalanced rotor on a wind turbine.

As a part of overall reliability and performance management of a wind farm, establishing acceptability criteria for rotor balance is essential for blade repair, wind turbine commissioning, end-of-warranty inspection, or reliability-centered maintenance program.

There is a phrase for those who ASSUME. A generally accepted balancing practice for a blade repair shop or for field determination of blade balance requires weighing the tip and root ends of each blade through the use of flexible straps supporting the blade at prescribed distances and a crane weighing scale.