Standards
nrellogs.gif (1024 bytes)
barstand.gif (6187 bytes)

 

 

 
IEC Wind Turbine Standards
International Standards Activities International standards are developed by the working groups of Technical Committee-88 (TC-88) of the International Electrotechnical Commission (IEC), the recognized international body for standards development activities.

NREL maintains contact with the International Electrotechnical Commission (IEC) standards development activities through the involvement of staff members on TC-88 standards subcommittees.

The status of the IEC standards is provided in Table I.

 
Table I
IEC Wind Energy Standards
Working
Group 		Title Convener Start Finish
(Plan or Actual) 		Purpose Document Number
WG-1
WG-2
WG-3 		Safety Requirements
for Large
Wind Turbines 		R. Sherwin, AWEA, USA 09/1989 12/1993 Principal standard defining design
requirements		 IEC 1400-1*
WG-4 Small Wind Turbine
Systems 		F.Van Hulle,
ECN, NL 		02/1992 01/1994 Principal standard defining design
requirements for small  turbines		 IEC 1400-2*
WG-5 Acoustic Emission Measurement
Techniques 		T.J. DuBois,
USA		 11/1992 09/1998 Defines acoustic
measurements
methods		 IEC 1400-11*
WG-6 Performance Measurement Techniques T. Pedersen,
Riso NL,
Denmark		 11/1992 01/1998 Defines performance measurement tech- niques IEC 1400-12*
WG-7 Revision of IEC 1400-1 P.H. Madsen,
Riso NL, DKr 		03/1994 01/1999 Edition 2 of IEC 1400-1 1400-1 Ed2
WG-8 Blade Structural Testing D.van Delft,
TU Delft, NL 		03/1994 1999 Defines methods for blade structural testing 1400-23
WG-9 Wind Turbine Certification Requirements J.McGuire,
Lloyds Register, UK 		10/1995 1999 Defines certifica-
tion requirements
(Harmonized version of several European standards.)		 1400-22
WG-10 Power Quality
Measurements 		J.O.Tande, Riso NL, DK 02/1996 1999 Defines power
quality measurement techniques		 1400-21
WG-11 Structural Loads Measurement F.Van Hulle,
ECN, NL 		02/1996 1999 Defines methods
for measuring
operational loads		 1400-13
*Published Standard
TC-88 Standards Working Groups This section provides brief summaries of IEC activities. Standards are not available for use or application until they exist as approved "Draft International Standards" or "International Standards." These documents should be ordered from ANSI, citing the document number in Table I and specifying whether the standard is draft or final.

 
 
WG 1, 2, 3 
Safety of Wind Turbine Generating Systems 		Background - The first three TC-88 working groups (Safety Philosophy, Design, and Installation and Operation) were originally chartered separately, but were combined when it became evident that their objectives and roles were interdependent.

Scope of Work - This international standard deals with safety philosophy, quality assurance and engineering integrity, and specifies requirements for the safety of Wind Turbine Generator Systems (WTGS), including design, installation, maintenance, and operation under specified environmental conditions. Its purpose is to provide the appropriate level of protection against damage from all hazards from these systems during their planned lifetime. This standard is concerned with all subsystems of WTGS such as control and protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and the electrical interconnection equipment. The standard applies to 1) all sizes of WTGS connected to electrical power networks and 2) WTGS with swept area equal to or larger than 40 m2.

Contact - Robert Sherwin, Atlantic Orient Corporation, USA

 
WG4
Safety Requirements for Small Wind Turbines 		Background - Standards for wind turbines with swept areas under 40 square meters (m2) were developed separately because of the unique control methods and features used by designers of these systems (such as foldable tails.) The separate standard was developed to avoid imposing costly requirements that would not result in improved safety of the smaller systems, which have different inherent risk factors than larger systems.

Scope of Work - Deals with safety philosophy, quality assurance, engineering integrity and specifies requirements for the safety of small wind turbine generators (SWTGS), including design, installation, maintenance and operation under specified external conditions. This standard is concerned with all subsystems of SWTGS such as protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and the electrical interconnection with the load. The standard applies to WTGS with swept area less than 40 m2.

Contact - F.Van Hulle, ECN, The Netherlands

 
WG5  
Acoustical Measurement Techniques 		Background - This standard was developed to provide a uniform methodology that will ensure consistency and accuracy in the measurement and analysis of acoustic emissions by Wind Turbine Generator Systems (WTGS). The standard was prepared with the anticipation that it would be applied by:

- The WTGS manufacturer striving to meet well defined acoustic emission performance requirements and/or a possible declaration system;

- The WTGS purchaser in specifying such performance requirements;

- The WTGS operator who may be required to verify that stated, or required, acoustic performance specifications are met for new or refurbished units;

- The WTGS planner or regulator who must be able to accurately and fairly define acoustical emission characteristics of WTGS in response to environmental regulations or permit requirements for new or modified installations.

Scope of Work - Presents sound measurement procedures that enable noise emissions of a wind turbine to be characterized. This involves using measurement methods appropriate to noise emission assessment at locations close to the machine, in order to avoid errors due to sound propagation, but far enough away to allow for the finite source size. The procedures described are different in some respects from those that would be adopted for noise assessment in community noise studies. The are intended to facilitate characterization of wind turbine noise with respect to a range of wind speeds and directions and comparisons between different wind turbines.

Contact - T.J. DuBois, DuBois and Associates, USA

 
WG6
Power Performance Measurement Techniques 		Scope of Work - Specifies a procedure for measuring the power performance characteristics of wind turbine generator systems of all types and sizes connected to the electric power network. It is applicable for both the determination of the absolute power performance characteristics of a WTGS and relative differences among the power performance characteristics of various WTGS configurations.

The WTGS power performance characteristics are defined by the measured power curve and the estimated annual energy production (AEP). The measured power curve is determined by collecting simultaneous measurements of wind speed and power output at the test site for a period long enough to establish a statistically significant database over a range of wind speeds and under varying wind conditions. The AEP is estimated by applying the measured power curve to reference wind speed frequency distributions, assuming 100% availability.

In 1995, participants in WG6 agreed to approve the draft standard with the understanding that extensions would be added to the scope of work. These extensions will handle the special requirements of power performance testing of small turbines, as well as testing of all turbines in complex terrain and in wind farm environments.

Contact: Troels Pedersen, Riso National Laboratory, Roskilde, Denmark

WG7  
Safety of Wind Turbine Generator Systems (Revision of IEC 1440-1) 		Background - Changes in the technology, increasing proliferation of wind turbine installations, and an increased understanding of environmental load cases for wind turbines have necessitated a revision of the safety requirements standards set forth by combined working groups 1, 2, and 3.

Scope of Work - Deals with safety philosophy, quality assurance and engineering integrity, and specifies requirements for the safety of Wind Turbine Generator Systems (WTGS), including design, installation, maintenance, and operation under specified environmental conditions. Its purpose is to provide the appropriate level of protection against damage from all hazards from these systems during their planned lifetime. This standard is concerned with all subsystems of WTGS such as control and protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and the electrical interconnection equipment. The standard applies to WTGS with swept area equal to or larger than 40 m2.

Contact - Peter H. Madsen, Riso National Laboratory, Denmark

WG8
Full Scale Structural Testing of Rotor Blades for WTGS 		Background - NREL and many other wind energy laboratories throughout the world are conducting static, dynamic fatigue, and modal tests of full-scale wind turbine blades using various test methods and configurations. This standard will help establish commonality among these methods and will provide guidelines to help ensure that results are comparable.

Scope of Work - This standard is intended to be used as a guideline for full scale testing of rotor blades of a WTGS as a possible part of a final design verification of the structural integrity of the blade. The tests included are fatigue tests, static tests, and modal tests. The standard describes recommended practices to perform various tests on full scale blades and gives guidance on interpretation or evaluation of results. It describes the blade and load data with the appropriate format necessary to evaluate the test results. Guidance is given on which (partial) safety factors should be incorporated during testing and evaluation.

Contact - Don van Delft, Delft University, The Netherlands

 
WG9 Certification Standard Scope of Work - Develop guidelines for certification and type approval of wind turbines using test data and analyses (scope of work under development).

Contact - John McGuire, Lloyds Register, UK

WG10
Power Quality Requirements for Grid Connected Wind Turbines 		Background - Existing certification procedures and other standards for wind turbines for grid connection do not deal with the requirements of the design of the turbine to minimize its effects on the power quality of the electrical network. As the power capacity/penetration increases, an evident need arises for a standardized specification of the power quality characteristics of the turbine output. and for defining requirements to the wind turbine design

Scope of Work - To prepare a standard for determining the characteristics of wind turbine output, with respect to the impact on the power quality in the public supply system, while securing proper operation of the wind turbine

Contact - J.O. Tande, Riso National Laboratory, Roskilde, Denmark

 
WG11
Load Measurements for WTGS 		Scope of Work - Develop guidelines for measuring loads on wind turbine structures (scope of work under development).

Contact - F. Van Hulle, ECN, The Netherlands

 
Obtaining Wind Energy Standards Documents

Order IEC Standards Documents:
American National Standards Institute

[ Back to Top ]

 
NREL's Technical Role in Standards Development NREL has one technical representative (employee or consultant) on most of the IEC Working Groups. NREL personnel have had a major impact on the standards development process, ensuring that standards do not impede international industry development and trade opportunities, while ensuring that environmental, safety, and health interests of industry employees, utility personnel, and the general public are maintained.

NREL also provides analytical support to standards development. For example, NREL employs its design codes and test data to validate the load cases used for wind turbine design standards developed under Working Group 7 (Safety of WTGS.) This is required to ensure that the cases accurately represent the full range of load environments that will be encountered by wind turbines. As a world leader in structural blade testing technology, NREL provides significant technical support to the development of the blade testing standard under Working Group 8. NREL personnel also participate in the periodic Technical Experts Meetings sponsored by the International Energy Agency. These meetings result in the development of recommended practices that are used in guiding the formation of standards under the IEC working groups.

|| Home || Certification || Testing || Evaluation || Standards || Information ||

Prepared by
National Wind Technology Center
National Renewable Energy Laboratory
Operated for the
U.S. DEPARTMENT OF ENERGY
by the Midwest Research Institute

Updated: November 21, 2002