Information model for IEC technical specification 61400-26-2: Production-Based Availability for Wind Turbines.

Information model for IEC technical specification 61400-26-2: Production-Based Availability for Wind Turbines.

The U.S. Department of Energy Wind Program and Sandia have been working with the International Elec­trotechnical Commission (IEC) Committee on Wind Turbine Availability to develop three specifications for IEC-61400-26the standard that addresses wind turbine and wind-plant availability. The first specification is on the definitions of operating states and availability conditions and was published in 2011.

The second specification is on time-based energy produc­tion and it defines a methodology for production ac­counting for differing operational states of a wind turbine, considering internal and exter­nal conditions. For example, it defines ac­counting for potential production, actual pro­duction, and lost production with determin­ation and example verification scenarios. The second specification has been completed and approved and will soon be published.

The third specification in this series is for production for a full wind-power station, including the bal­ance-of-plant (BoP) components of energy-collection systems, substa­tion and interconnection, and pro­visions for the human (functional) element of operations and mainten­ance. Based on the Sandia Contin­uous Reliability Enhancements for Wind (CREW) team’s observations and experience, common mode fail­ures will affect multiple elements of the wind-power station’s BoP tur­bines. Although the BoP does not generate power, its failures adverse­ly affect both time and production-based availability. These failures im­pact the BoP’s role in electricity transmission and the turbines’ de­pendency on the nonturbine com­ponents.

This work will lead to standardized and mandatory reporting metrics for full wind plants when the technical specifications are invoked as a standard and/or requirement. These standards help to define requirements to support clear understanding of contract terms for performance of turbines and wind plants. This is achieved by providing an information model specifying how time desig­nations shall be split into information categories. The accompanying illustration and table identifies the information model accounting for time, as well as measured and calculated energy.

IEC 61400-26 identifies a common basis for information exchange on performance indicators between owners, utilities, lenders, operators, manufacturers, consultants, regulatory bodies, certification bodies, insurance companies, and other stakeholders in the wind-power business.  It is used to help define require­ments to support clear understanding of contract terms.