Release of revised IEC 61400-4:2025 “Design requirements for wind turbine gearboxes”

The British Gear Association (BGA) is dedicated to shaping worldwide Gear Industry’s standards. Members of the BGA’s Technical Research Management Committees (TRMC) and Executive Council bring their expertise to ISO Working Groups, helping to refine standards for various gear disciplines.

It is essential that you keep up to date with the latest Gear Standards and in this vein the BGA TRMC would like to bring your attention to a significant update in the IEC 61400-4:2025 “Design requirements for wind turbine gearboxes”

We urge Members to familiarise themselves with the updated document which is temporarily available for BGA Members in the BGA Online Standards Library (please note you will need to be logged in to view the library.)

Please see below information on this revision from the BGA Technical Research Management Team.

IEC 61400-4:2025 is the latest edition of the application standard for “Design requirements for wind turbine gearboxes”.  It represents the first major revision since 2012 and provides comprehensive requirements for specification, design and verification of wind turbine gearboxes. It provides lots of useful information that can be applied to other gearbox applications and is available now in the BGA members standards library.

The 2025 edition introduces several significant revisions compared to the 2012 version:

• The expanded scope means the standard now applies to wind turbines with a reference power rating over 2 MW, accommodating the trend toward larger turbine capacities.

• The reliability integration consolidates various approaches across standards for gearboxes, bearings, and wind turbines, promoting a unified reliability framework.

• A new section on drive train load analysis focuses specifically on the loading of wind turbines at the drivetrain level, ensuring thorough load evaluation.

• The verification and validation sections have been overhauled to align with current best practices and technological advances.

• New requirements for sliding bearing design have been introduced, tailored to their specific use in wind turbine gearboxes.

• Bearing failure prevention is addressed through enhanced design considerations aimed at reducing common failure modes and improving reliability.

• Guidelines for structural element analysis have been revised to meet the increasing mechanical demands of wind turbine operation.

• The lubrication systems update reflects the latest in lubricant technology and system design.

• Documentation of compliance now references IECRE OD-501-2.

• This main document will be supported by additional documents which are still are still under development:

  • Design reliability assessment will be specified in IEC/TS 61400-4-1.

  • Additional information on lubrication will be provided in IEC/TR 61400-4-2.

  • IEC/TR 61400-4-3 will include the explanatory notes and supportive information.

  
  

These documents have been prepared by the IEC/TC88 “Wind energy generation systems” in cooperation with ISO/TC60 “Gears”. If you would like to be involved in the development of similar documents please contact admin@bga.org.uk.  

For more information, visit https://knowledge.bsigroup.com/products/wind-energy-generation-systems-part-4-design-requirements-for-wind-turbine-gearboxes