Certification in the Windpower domain

provided by: ALSTOM

Wind turbines are machines according to the definition of the EU Machinery Directive. Therefore they must be compliant with directive 2006/42/EC, and meet functional safety specifications.

The IEC 61400 standard is especially relevant as it focuses on wind turbine systems. However, it does not include any instruction on how to design safety-relevant parts of the control. The ISO 13849 and IEC 62061 standards provide support for this task, since they are appropriately harmonized. They both reference IEC 61508 domain independent standard.

The Guideline 2010 “Guideline for the Certification of Wind Turbine” shall also be mentioned. This document, elaborated by GL Renewables Certification provides in Chapter 2 the safety requirements necessary to ensure that the components of the wind turbine are always kept within their operation limits. This is achieved by the implementation of protection functions, such as:

  • Protection against excessive rotor speed
  • Protection against excessive power production
  • Protection against short circuit
  • Etc.

All these functions shall be performed by the safety (protection) system. The guideline recommends performance level “PL d” for most of the protection functions, and that shall be also the performance level met by the safety system.

The proposed architecture includes different safety and control systems, as shown in the following figure, extracted from the Guidelines (GL), see reference below. If they are deployed on the same platform, thus conforming a mixed-criticality system, appropriate measures shall be taken in order to guarantee independence.

 

Standards referenced:

  • EC "Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)".
  • IEC 61400: Wind Turbines generator systems, ed, 2005.
  • ISO 13849: Safety of Machinery, ed, 2006.
  • IEC 62061: Safety of machinery: Functional safety of electrical, electronic and programmable electronic control systems, ed, 2005.
  • IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related systems, ed, 2010.
  • Guidelines of Germanischer Lloyd Industrial Services (GL), ed, 2010.