Detectiong blade failures in wind turbines

Rotor blades are critical components of wind turbines, enduring various weather conditions and high speeds. It’s crucial to monitor their condition closely to ensure optimal performance and safety.

 

Let’s explore some common types of surface damage observed that lead to blade failures in wind turbines.

If damage or impairments remain undetected, this can have costly consequences and lead to blade failures in wind turbines. Below, we will examine the most common types of damage:

 

Erosion

Erosion occurs due to the impact of airborne particles such as sand, rain, or hail. Over time, these particles can wear away the surface of the turbine blades, leading to reduced aerodynamic efficiency and potential imbalance. Erosion is much more intense at the leading or trailing edge near the tip. If not repaired quickly, it can lead to cracks in the laminates or allow water to penetrate into the bond line. Our surface damage detection system makes it possible to detect erosion damage at an early stage.

 

Corrosion

Corrosion can be caused by exposure to moisture, saltwater, or chemicals in the environment. It typically affects metal components such as the tower, nacelle, and other structural elements, leading to weakening and structural integrity issues.

 

Cracking

Cracks may develop in turbine components due to factors such as material fatigue, stress concentration, or manufacturing defects. Cracks can propagate over time, leading to structural failure if not addressed. Intelligent monitoring systems such as our ground-breaking technology alert operators to changes at an early stage.

Delamination

Delamination occurs when layers of composite materials used in turbine blades separate from each other. This can be caused by manufacturing defects, prolonged exposure to environmental factors, or improper maintenance.

 

Debonding

Debonding refers to the separation of layers within the composite structure of the rotor blade. This occurs when the upper and lower shells of the blade separate, usually at the tip or trailing edge in the outer few meters of the blade. Debonding is often triggered by lightning strikes. The lightning strike heats the air inside the rotor blades, causing it to expand and generate internal pressure. Condensed moisture inside the blade, which evaporates due to the heat of the lightning strike, can increase debonding.

 

Blade leading edge damage

Leading edge erosion is particularly common on turbine blades and can result from the impact of raindrops, hail, or airborne debris. This erosion reduces the aerodynamic efficiency of the blades and can lead to reduced energy production.

Paint damage

The paint on turbine blades and other components can deteriorate over time due to exposure to UV radiation, temperature fluctuations, and environmental pollutants. This not only affects the aesthetics but also leaves underlying materials vulnerable to corrosion and other forms of damage.

 

Lightning strikes

Wind turbines are often tall structures and can attract lightning strikes during thunderstorms. These strikes can cause surface damage, including burn marks, pitting, and melting, compromising the structural integrity of affected components. To make the inspection of turbines after a thunderstorm as efficient as possible, there are monitoring solutions such as our ON-TOWER system, which shows operators exactly whether and which turbines have been struck by lightning. This saves time and resources.

Ice accretion

In colder climates, ice can accumulate on turbine blades and other surfaces during freezing conditions. The added weight and imbalance caused by ice accretion can strain the turbine components and lead to surface damage upon ice shedding.

Bolt loosening

Vibrations and operational stresses can cause bolts and fasteners to loosen over time, leading to surface damage and potential failure if not addressed promptly.

 

Biological growth

In humid and damp environments, biological organisms such as algae, fungi, and moss can grow on turbine surfaces. This not only affects the appearance but can also compromise the structural integrity of the components if left unchecked.

Regular inspection, maintenance, and timely repair are essential to mitigate these surface damages and ensure the optimal performance and longevity of wind turbines. Our leading-edge damage detection system helps you secure your turbines from damages. It can detect acoustically different types of damages like:

• Tip damage
• Erosion
• Goug and Cracks
• Split tip
• Holes
• Delamination
• Lightning strikes

 

Wind farm operators are able to make data-driven decisions based on the data visible in the dashboard. This helps operators to save costs and avoid damage to wind turbines.

 

For further information, please contact our sales team directly or discover our technology on our website.

 

Reference:

• Leon Mishnaevsky, Jr., Małgorzata Sikora, Tadeusz Bohdal (2022): Root Causes and Mechanisms of Failure of Wind Turbine Blades: Overview. Department of Wind Energy, Risø Campus, Technical University of Denmark. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9101399/
• Papadakis Nikos, Ntintakis Ioannis (2021): A Comprehensive Analysis of Wind Turbine Blade Damage. Energies; Basel. https://www.proquest.com/docview/2576397519?sourcetype=Scholarly%20Journals