Catégories: Matériaux de résistance , Énergie éolienne
Publié 12 déc. 2024

Watching a wind turbine spin on the horizon, it’s hard to fathom how many components are in unison to ensure proper and safe functioning. Among these, braking resistors play a critical yet understated role—dissipating excess energy generated during braking and converting it into heat to maintain stability.

 

Nevertheless, braking resistors are as reliable and versatile as the materials they’re made of.

The right material choice is more a strategic investment than a technical decision for the longevity, safety, and sustainability of wind farm operations.

Electric resistance materials must endure immense heat, mechanical stress, and harsh environmental conditions while being responsible for efficiency and durability. Therefore, the right material choice is more a strategic investment than a technical decision for the longevity, safety, and sustainability of wind farm operations.

To understand this better, let’s explore the factors that make electric resistance material exceptional and dig deeper into Kanthal’s alloys and expertise in this space.

The science behind electric resistance materials 

Braking resistors work under extreme conditions; therefore, top-of-the-tier electric resistance materials must possess specific properties: 

1. Temperature Coefficient of Resistance (TCR)

Low TCR to maintain stable resistance across varying temperatures, ensuring consistent braking performance and reducing the risk of overheating. 

2. Power rating

High power rating to handle significant energy dissipation during braking, enhancing reliability under demanding operating conditions. 

3. Oxidation and corrosion resistance

Ability to withstand high temperatures, chemical reactions, and environmental exposure to minimize maintenance needs. 

4. Creep strength

The capability to resist deformation under sustained mechanical stress and high heat.  

5. Emissivity

High-emissivity materials radiate heat efficiently, preventing overheating and maintaining operational efficiency. 

6. Magnetic properties

Non-magnetic materials are preferred when reducing magnetic interference is crucial for accuracy and reliability. 

7. Temperature rating

The materials must endure high operating temperatures without degrading. 

8. Economy and availability

Balancing upfront costs with long-term savings is essential. Materials must also be readily available from reliable suppliers to minimize downtime during maintenance or replacement. 

9. Compatibility with cooling systems

Resistance materials must integrate seamlessly with cooling systems to manage heat dissipation effectively. 

10. Environmental regulations

Materials must comply with regulations, especially in ecologically sensitive areas, to ensure sustainable operations. 

Kanthal’s electric resistance materials: Meeting every need 

Kanthal’s materials are meticulously engineered to take every challenge head-on. Each alloy handpicked for specific wind farm applications brings unique advantages, that allow engineers to select the best option.  

Nikrothal® 40 - A dependable starting point 

Nikrothal® 40 (wire/ strip) is an austenitic nickel-chromium alloy (NiCr alloy) for use at temperatures up to 1,100°C (2,010°F). 

  • Oxidation resistance: Fair 
  • Creep strength: Good 
  • Corrosion resistance: Good 
  • Temperature rating: Good 
  • Magnetic: No 
  • Emissivity: Excellent 
  • Economy: Good 
  • Temperature coefficient: High 

 

Nikrothal® 60 - The versatile performer 

Nikrothal® 60 (wire/ strip) is an austenitic nickel-chromium alloy (NiCr alloy) for use at temperatures up to 1150°C (2100°F). 

  • Oxidation resistance: Good 
  •  Creep strength: Excellent 
  • Corrosion resistance: Excellent 
  • Temperature rating: Good 
  • Magnetic: Slightly 
  • Emissivity: Excellent 
  • Economy: Good 
  • Temperature coefficient: Medium 

 

Nikrothal® 80 - Engineered for extremes 

Nikrothal® 80 (wire/ strip) is an austenitic nickel-chromium alloy (NiCr alloy) for use at temperatures up to 1200°C (2190°F). 

  • Oxidation resistance: Good 
  • Creep strength: Excellent 
  • Corrosion resistance: Excellent 
  •  Temperature rating: Excellent 
  • Magnetic: No 
  • Emissivity: Excellent 
  • Economy: Fair 
  • Temperature coefficient: Low 

 

Kanthal® D - High-temperature specialist 

Kanthal® D (wire/ strip) is a ferritic iron-chromium-aluminum alloy (FeCrAl alloy) for use at temperatures up to 1300°C (2370°F).  

  • Oxidation resistance: Excellent 
  • Creep strength: Fair 
  • Corrosion resistance: Fair 
  • Temperature rating: Excellent 
  • Magnetic: Yes 
  • Emissivity: Good 
  • Economy: Excellent 
  • Temperature coefficient: Low 

 

Alkrothal® 14 - Efficiency at value 

Alkrothal® 14 (wire/ strip) is a ferritic iron-chromium-aluminum alloy (FeCrAl alloy) with high resistivity suitable for use at temperatures up to 1100°C (2010°F). 

  • Oxidation resistance: Good 
  • Creep strength: Fair 
  • Corrosion resistance: Fair 
  • Temperature rating: Good 
  • Magnetic: Yes 
  • Emissivity: Good 
  • Economy: Excellent 
  • Temperature coefficient: Medium 

 

Alkrothal® 720 – High value proposition 

Alkrothal® 720 (wire/ strip) is a ferritic iron-chromium-aluminum alloy (FeCrAl alloy) for use at temperatures up to 1000°C (1830°F). 

  • Oxidation resistance: Good 
  • Creep strength: Fair 
  • Corrosion resistance: Fair 
  • Temperature rating: Good 
  • Magnetic: Yes 
  • Emissivity: Good 
  • Economy: Excellent 
  • Temperature coefficient: Medium 

Kanthal: A trusted partner  

Kanthal’s expertise in electric resistance materials is built on more than 90 years of innovation and a deep knowledge of industrial challenges. Kanthal offers top-class materials and comprehensive systems tailored to the unique demands of wind farms. To make an informed choice, suitable alloys must be picked keeping in mind durability, capacity optimization, material usage, and operational cost as these aspects directly impact the overall performance of wind energy systems. Choose Kanthal as your partner to develop a future where renewable energy operates at its highest potential.