Induction heating in the wind turbine industry

Heating up the winds of change

Constant, clean and cost-effective—wind power is one of the fastest growing energy sources in the world, providing ever more people with reliable, affordable and sustainable electricity. What role has induction technology played in the promotion of green wind power?

EFD Induction is the world’s leading supplier of heating solutions for the renewable energy sector. Our technology has already made tremendous contributions to the efficiency, safety and profitability of the wind turbine industry – making the manufacture and maintenance of the turbines a clean and green process.

A clean and green process

Induction is an inherently clean process. It is more energy-efficient and eco-friendly than other heating alternatives. It does not emit carbon dioxide. It eliminates naked flames, reduces the need for fuel transport, and promotes safer, healthier workplaces. Product quality and process consistency are crucial to the wind turbine industry, which is why accurate, repeatable and contact-free induction heating has become standard with wind turbine manufacturers and their suppliers.Wind turbines are exposed to ferocious weather conditions, so the they must be constructed to resist violent winds, particularly in harsh offshore environments. The rotor bearings and large gears must be custom hardened to withstand the heavy loads and punishing torque, and several high-quality, mission-critical components require shrink fitting, brazing and pre-heating.  

Induction heating is used on almost every part of a typical modern wind turbine.

  • Cable heating
  • Preheating before welding of baseplate
  • Bolt heating on tower foundation
  • Brazing components in high-voltage step-up transformer
  • Brazing of terminal ends on high voltage cable
  • Preheating before welding of tower rings
  • Hardening of pitch bearings
  • Stator house shrink fitting of yaw motor and pitch motor
  • Hardening of bearings and slewing rings
  • Shrink fitting of main shaft bearings and sleeve rings
  • Hardening of gearbox shaft and bearings
  • Hardening of generator bearings
  • Brazing of stator and rotor windings
  • Brazing components in high-voltage step-up transformer
  • Gear hardening of yaw drives and slewing ring

Induction hardening systems for every hardening job

HardLine is EFD Induction’s family of heat treatment systems for surface and through hardening, comprising a complete range of stationary systems for all types of workpieces requiring hardening and tempering. Large bearing is needed in order for the rotors to turn, but not just any bearing will do. Due to heavy loads and punishing torque, the rotor bearing must be custom hardened—something for which our patented seamless hardening process and the hardening machine, multi-axis area portals are ideal. EFD Induction vertical hardening systems are also perfect for treating the shaft connecting the rotors to the gearbox In gear with multi-frequency The heart of any wind turbine is the gearbox. Here, the leisurely turns of the rotor blades are transformed into the approximately 1500 revolutions per minute required by the generator. EFD Induction hardening systems can be used for the tooth-by tooth hardening of the yaw motor. Crucial to the turbine, the yaw motor keeps the rotors turned into the wind. The yaw motor swivels the rotors into the correct position by means of a cam wheel that engages a large yaw bearing mounted on the turbine tower. An electronic controller that is constantly fed data by an anemometer mounted on the nacelle tells the yaw motor when to turn the rotors. 

Mobile, flexible and easy to use

EFD Induction’s contribution to wind turbines is not limited to component hardening. The Minac is suitable for a wide range of applications. Featuring long flexible connector cables and push-trigger hand-held transformers, Minac systems let operators heat even the most difficult-to reach parts. Moreover, Minac comes in ‘twin’ versions. These models feature two independent power outputs that can function simultaneously under identical or different operating parameters. The Minac’s mobility also makes it ideal for on-site repairs and maintenance at wind farms. 


A beautiful partnership

At EFD Induction, we are dedicated to support the shift from fossil-based energy production to renewable energy sources. In fact, induction and wind power form a ‘virtuous circle’—clean electricity from the wind, powers induction heating systems that make turbines that generate clean electricity.It’s a beautiful partnership – one that EFD Induction is proud to be a part of. Learn more about induction in the wind turbine industry and feel free to book a meeting.

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