In the context of the rapid development of the modern wind power industry, especially high-power onshore and offshore wind turbines, vibration has become one of the core factors affecting wind turbine safety, lifespan, power generation, and operation and maintenance costs. As wind turbine hub height continues to increase, blade length continues to lengthen, and single-unit capacity continues to grow, problems such as wind vibration, tower resonance, blade swaying, transmission chain vibration, and foundation vibration faced by wind turbines during operation are becoming increasingly prominent.
So, why is a vibration damper necessary for wind power operations? Turbulent winds, gusts, shear winds, and the tower shadow effect cause the blades to experience periodically varying thrust, leading to blade flapping and oscillation, which is transmitted to the hub, main shaft, gearbox, and tower, resulting in continuous vibration. Impeller mass imbalance, main shaft misalignment, bearing wear, and gearbox gear meshing impacts all generate high-frequency vibrations, which are major causes of transmission chain failures. The tower is a slender, flexible structure with a low first-order natural frequency, making it prone to resonance with the impeller rotation frequency and blade passage frequency. Once resonance occurs, the vibration amplitude is drastically amplified, threatening structural safety.
What hazards does vibration cause to wind turbines? Under continuous vibration, the fatigue life of gearboxes, bearings, main shafts, and yaw systems is significantly shortened, and the failure rate increases significantly. Vibration can cause tower flange bolts and main frame bolts to loosen, and in severe cases, fatigue cracks may appear in the welds. Exceeding vibration limits will trigger the main control system's load reduction, speed limiting, and shutdown protection, directly reducing power generation time and output. Vibration-related failures account for more than 50% of all wind turbine failures, and high-altitude maintenance and offshore operation and maintenance costs are extremely high. Long-term resonance or extreme vibration may lead to blade cracking, tower deformation, foundation damage, and even serious safety accidents.
This article introduces the application of vibration dampers on wind turbine blades. Blades are the most violently vibrating components, primarily exhibiting flapping, oscillation, flutter, and icing-induced unbalanced vibration. Internally tuned mass dampers, installed at 20%–40% of the blade's length, utilize a mass block, springs, and damping structure to tune with the blade's vibration frequency, effectively suppressing first- and second-order oscillations and flapping vibrations, reducing fatigue bending moment at the blade root, and extending blade life.
The use of vibration dampers reduces blade vibration amplitude by 30%–60%, reduces blade fatigue damage by over 40%, decreases the risk of blade cracking and debonding, and mitigates the unbalanced impact from icing vibration.
The wind power industry commonly uses vibration dampers of various types and working principles. The most widely used type is the tuned mass damper, which consists of a mass block, a spring, and a damper. The frequency is tuned to the main vibration frequency of the wind turbine. When vibration occurs, the mass block moves in the opposite direction to consume energy. It has a reliable structure, stable effect, and wide applicability.
Offshore wind turbines operate in environments several times harsher than onshore turbines. Therefore, the vibration damper must meet high corrosion resistance requirements, including hot-dip galvanizing, 316L stainless steel, Dacromet coating, salt spray testing for over 1000 hours, and stable operation at temperatures ranging from -40℃ to 80℃. Offshore maintenance costs are extremely high, necessitating a long-life design. The hydraulic damper must also be designed to prevent oil leaks that could pollute the ocean.
What practical benefits can wind farms gain from using Vibration Damper?
Increased power generation, reduced vibration-triggered power limitations and downtime, stable operation in turbulent wind zones, and an overall power generation increase of 2%–8%; extended lifespan of core components, with blade life increased by 20%–40%, gearbox life increased by 30%–50%, and tower fatigue damage reduced by 30%–60%; significantly reduced operation and maintenance costs, fewer high-altitude maintenance operations, fewer gearbox and bearing replacements, saving thousands to tens of thousands of US dollars per offshore wind turbine per year; improved overall turbine safety, avoiding resonance, enhancing survivability under typhoons, earthquakes, and waves, and reducing the risk of bolt loosening and structural cracking; reduced noise, with decreased aerodynamic and structural noise, meeting environmental protection requirements and facilitating project approval.
