IEC TS 61400-26-1:2011

Wind turbines - Part 26-1: Time-based availability for wind turbine generating systems

IEC 61400-26-1:2011(E) defines generic information categories to which fractions of time can be assigned for a wind turbine generating system (WTGS) considering internal and external conditions based on fraction of time and specifying the following:
- generic information categories of a WTGS considering availability and other performance indicators;
- information category priority in order to discriminate between concurrent categories;
- entry and exit point for each information category in order to allocate designation of time;
- informative annexes providing various examples.

General Information

• Status: Replaced
• Publication Date: 13-Nov-2011
• ICS: 27.180 - Wind turbine energy systems
• Technical Committee: TC 88 - Wind energy generation systems
• Drafting Committee: WG 26 - TC 88/WG 26
• Current Stage: DELPUB - Deleted Publication
• Start Date: 30-Mar-2018
• Completion Date: 29-May-2019

Relations

• Revised: IEC 61400-26-1:2019 - Wind energy generation systems - Part 26-1: Availability for wind energy generation systems
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC/TS 61400-26-1


®


Edition 1.0 2011-11



TECHNICAL



SPECIFICATION




colour
inside
Wind turbines –
Part 26-1: Time-based availability for wind turbine generating systems



IEC/TS 61400-26-1:2011(E)

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IEC/TS 61400-26-1


®


Edition 1.0 2011-11



TECHNICAL



SPECIFICATION




colour
inside
Wind turbines –
Part 26-1: Time-based availability for wind turbine generating systems



INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XA
ICS 27.180 ISBN 978-2-88912-780-1

® Registered trademark of the International Electrotechnical Commission

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– 2 – TS 61400-26-1 © IEC:2011(E)



CONTENTS

FOREWORD . 4


1 Scope . 7

2 Normative references . 7

3 Terms, definitions and abbreviations . 7


3.1 Terms and definitions . 7

3.2 Abbreviations . 8

4 Information model . 9

4.1 General . 9
4.2 Information categories . 9
4.3 Limitations . 9
4.4 Information category priority . 11
5 INFORMATION AVAILABLE . 12
5.1 OPERATIVE . 13
5.1.1 GENERATING . 13
5.1.2 NON-GENERATING . 15
5.2 NON-OPERATIVE . 20
5.2.1 SCHEDULED MAINTENANCE . 21
5.2.2 PLANNED CORRECTIVE ACTION . 22
5.2.3 FORCED OUTAGE . 23
5.2.4 SUSPENDED . 24
5.3 FORCE MAJEURE . 24
6 INFORMATION UNAVAILABLE . 25
Annex A (informative) Optional information categories – examples . 27
Annex B (informative) Time based availability indicators – examples . 40
Annex C (informative) Verification scenarios – examples . 44
Bibliography . 53

Figure 1 – Information category overview . 10
Figure 2 – Information category priority . 11
Figure 3 – INFORMATION AVAILABLE category . 12
Figure 4 – OPERATIVE category . 13

Figure 5 – GENERATING category . 14
Figure 6 – FULL PERFORMANCE category . 14
Figure 7 – PARTIAL PERFORMANCE category . 15
Figure 8 – NON GENERATING category . 16
Figure 9 – TECHNICAL STANDBY category . 17
Figure 10 – OUT OF ENVIRONMENTAL SPECIFICATION category . 18
Figure 11 – REQUESTED SHUTDOWN category . 19
Figure 12 – OUT OF ELECTRICAL SPECIFICATION category . 20
Figure 13 – NON-OPERATIVE category . 21
Figure 14 – SCHEDULED MAINTENANCE category . 22
Figure 15 – PLANNED CORRECTIVE ACTION category. 23
Figure 16 – FORCED OUTAGE category . 23

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TS 61400-26-1 © IEC:2011(E) – 3 –


Figure 17 – SUSPENDED category . 24

Figure 18 – FORCE MAJEURE category . 25


Figure 19 – INFORMATION UNAVAILABLE category . 26

Figure A.1 – Information category overview – mandatory and optional . 28

Figure A.2 – Optional categories for PARTIAL PERFORMANCE . 29


Figure A.3 – Derated category . 30

Figure A.4 – Degraded category . 30

Figure A.5 – Optional categories for OUT OF ENVIRONMENTAL SPECIFICATION . 31


Figure A.6 – Calm winds category . 32
Figure A.7 – Other environmental category . 33
Figure A.8 – Optional categories for NON-OPERATIVE . 34
Figure A.9 – Optional categories for forced outage . 35
Figure A.10 – Workflow breakdown structure . 36
Figure A.11 – Optional categories for SUSPENDED. 38
Figure C.1 – Verification scenarios – time allocation to information categories . 44
Figure C.2 – Verification scenarios – communication aspects . 45
Figure C.3 – Verification scenarios – partial operational aspects . 46
Figure C.4 – Verification scenarios – maintenance aspects . 47
Figure C.5 – Verification scenarios – operational aspects . 49
Figure C.6 – Verification scenarios – grid / electrical network aspects . 50
Figure C.7 – Verification scenarios – environmental aspects . 52

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INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________



WIND TURBINES –



Part 26-1: Time-based availability for wind turbine generating systems





FOREWORD


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The main task of IEC technical committees is to prepare International Standards. In

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Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 61400-26-1, which is a technical specification, has been prepared by IEC technical
committee 88: Wind turbines.

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TS 61400-26-1 © IEC:2011(E) – 5 –


The text of this technical specification is based on the following documents:


Enquiry draft Report on voting

88/387/DTS 88/415/RVC



Full information on the voting for the approval of this technical specification can be found in

the report on voting indicated in the above table.


This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts of the IEC 61400 series, under the general title Wind turbines, can be found
on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual edition of this document may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
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understanding of its contents. Users should therefore print this document using a
colour printer.

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INTRODUCTION


The intention of this technical specification is to define a common basis for exchange of
information on performance indicators between owners, utilities, lenders, operators,
manufacturers, consultants, regulatory bodies, certification bodies, insurance companies and

other stakeholders in the wind power generation business. This is achieved by providing an

information model specifying how time designations shall be split into information categories.

The information model forms the basis for allocation of time for reporting availability and

reliability indicators.


The technical specification defines generic terms of wind turbine systems and environmental

constraints in describing system and component availability, lifetime expectancy, repairs and
criteria for determining overhaul intervals. The specification defines terminology and generic
terms for reporting wind power based generating unit availability measurement. A generating
unit includes all equipment up to the termination point defined in the distribution code (grid
code) agreed between the generation party and the distribution / transmission party.
Availability measurements are concerned with fractions of time a unit is capable of providing
service, taking environmental aspects into account. Environmental aspects will be wind and
other weather conditions, as well as grid and substation conditions. The specification
furthermore defines terminology and terms for reporting performance indicators based on
power production or capacity. Mandatory information categories defined in the technical
specification are written in capital letters; optional information categories defined in the
technical specification are written in bold letters.
The project scope is accomplished by separating the technical specification into two parts:
• IEC/TS 61400-26-1 specifies terms for time based availability of a wind turbine
generating system;
• IEC/TS 61400-26-2 specifies terms for production based availability of a wind turbine
generating system.

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TS 61400-26-1 © IEC:2011(E) – 7 –


WIND TURBINES –



Part 26-1: Time-based availability for wind turbine generating systems







1 Scope


This part of IEC 61400 defines generic information categories to which fractions of time can

be assigned for a wind turbine generating system (WTGS) considering internal and external
conditions based on fraction of time and specifying the following:
• generic information categories of a WTGS considering availability and other performance
indicators;
• information category priority in order to discriminate between concurrent categories;
• entry and exit point for each information category in order to allocate designation of time
• informative annexes including:
– examples of optional information categories,
– examples of algorithms for reporting availability and performance indicators,
– examples of application scenarios.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-415:1999, International Electrotechnical Vocabulary – Part 415: Wind turbine
generator systems Available from: http://www.electropedia.org/
IEC 61400-1, Wind turbines – Design requirements
3 Terms, definitions and abbreviations
For the purposes of the present document, the following terms, definitions and abbreviations

apply, as well as the relevant terms and definitions contained in IEC 60050-415.
3.1 Terms and definitions
3.1.1
availability
fraction of a given operating period in which a WTGS is performing its intended services
within the design specification
3.1.2
design specifications
collection of precise and explicit information about requirements for a product design
It provides in-depth details about the functional and non-functional design requirements
including assumptions, constraints, performance, dimensions, weights, reliability and
standards. For example, specifications and design considerations given in IEC 61400-1 define
the process for producing design specifications for WTGS.

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3.1.3

external conditions

conditions outside of the WTGS that affect the operation of the WTGS, for example (i) out of

environmental specification and (ii) out of electrical specification


3.1.4

permanent storage

type of computer storage that keeps the data or its contents regardless of whether the power

is turned off or if the storage device is moved to another computer

The most commonly used permanent storage is the computer hard disk drive.


3.1.5
reliability
probability that a component part, equipment, or system will satisfactorily perform its intended
function under given circumstances for a specified period of time
3.1.6
repair
activity whereby components of a system are restored to a safe operating condition following
an unpredicted or unforeseen failure
3.1.7
retrofit
incorporation of new technology or new design parts resulting from an approved engineering
change to an already supplied item
3.1.8
total time
the total calendar time of the period selected
3.2 Abbreviations
IA Information available category
IAO Information available operative category
IAOG Information available operative generating category
IAOGFP Information available operative generating with full performance category
IAOGPP Information available operative generating with partial performance category
IAONG Information available operative non generating category
IAONGTS Information available operative non generating technical standby category

IAONGEN Information available operative non generating out of environmental
specification category
IAONGENC Information available operative non generating out of environmental
specification optional category calm winds
IAONGENO Information available operative non generating out of environmental
specification optional category other environmental
IAONGEL Information available operative non generating out of electrical specification
category
IAONGRS Information available operative non generating requested shutdown category
IAN Information available non operative category
IANSM Information available non operative scheduled maintenance category
IANPCA Information available non operative planned corrective action category
IANFO Information available non operative forced outage category
IANS Information available non operative suspended category

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TS 61400-26-1 © IEC:2011(E) – 9 –


IAFM Information available force majeure category

IU Information unavailable category


SCADA Supervisory control and data acquisition

WTGS Wind turbine generating system

TT Total time


4 Information model


4.1 General

The information model is comprised of different information categories. All calendar time shall
be distributed into these information categories.
Each information category has an associated entry point and exit point. The entry point
describes the criteria that have to be fulfilled to allocate time into a specific information
category. The exit point describes the criteria to be fulfilled to end time allocation to a specific
information category.
The information model is split into five levels and the hierarchy shall be understood from level
one to level five i.e. all attributes of overlaying information categories are inherited by
underlying information categories. The time designations are allocated at the lowest
mandatory level. Overlaying information categories shall contain the sum of the related
information categories on the underlying level. The information categories are introduced in
4.2.
In case entry conditions are fulfilled concurrently for two or more information categories, time
shall be assigned into the information category with the highest priority only. Information
category priorities are described in more details in 4.4.
4.2 Information categories
Information categories are counters for accumulation of time periods with specified attributes
defined for a WTGS for the purpose of exchange of information on availability.
Figure 1 is an overview of the information categories defined in this technical specification.
The information model includes four mandatory categories. The model also allows for
additional optional levels of information categories to provide the user with more detailed data.
Compliance with this technical specification requires designation of time periods into the
mandatory information categories defined in level 1 to level 4, as shown in Figure 1.

The optional information categories defined in level 5 are not required to be compliant with
this specification; they are included to allow users to customize reporting details to meet their
specific requirements. This specification imposes no limits on the number of optional
information categories or levels added by the individual users. The optional information
categories shown in Figure 1 are for illustrative purposes only and are described in Annex A.
All optional information categories shall be located on level 5 or higher in order to be
compliant with this technical specification.
Abbreviations for the various information categories are indicated in brackets with bold letters.
The abbreviations are defined in Clause 3.
4.3 Limitations
It is not in the scope of this technical specification to determine the method of information
acquisition.

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 Information categories

Mandatory Mandatory Mandatory Mandatory Optional -

Level 1 Level 2 Level 3 Level 4 description

see Annex A

Level 5

FULL
PERFORMANCE
(IAOGFP)


PARTIAL Derated

PERFORMANCE
(IAOGPP)
Degraded
TECHNICAL
STANDBY
(IAONGTS)
OUT OF Calm winds
ENVIRONMENTAL
SPECIFICATION
Other
(IAONGEN)
environmental
REQUESTED
SHUTDOWN
(IAONGRS)
OUT OF
ELECTRICAL
SPECIFICATION
(IAONGEL)
SCHEDULED MAINTENANCE
(IANOSM)
Retrofit
PLANNED CORRECTIVE ACTION

(IANOPCA)
Upgrade
Other
corrective
action
Response
FORCED OUTAGE
(IANOFO) Diagnostic
Logistic

Failure repair
SUSPENDED Scheduled
(IANOS)
maintenance
Planned
corrective
action
Forced outage
FORCE MAJEURE
(IAFM)
INFORMATION UNAVAILABLE
(IU)
Figure 1 – Information category overview
The information categories are described in further details in Clause 5, Clause 6 and Annex A.
INFORMATION AVAILABLE
(IA)
NON-OPERATIVE
OPERATIVE
(IANO)
(IAO)


NON-GENERATING GENERATING
(IAONG) (IAOG)

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TS 61400-26-1 © IEC:2011(E) – 11 –


4.4 Information category priority


Time present in the information categories shall be exclusive and continuous. In case the

conditions for allocating a time period to more than one information category are fulfilled at

the same time, the information category priorities determine which category takes precedence

for the allocation of the time period being considered. Assignment of priorities to the
information categories provides a uniform and transparent method for designation of time.



The order of priorities as specified in Figure 2 is mandatory for compliance with this model.
The priorities are ranked from one to twelve with one as the lowest and twelve as the highest

priority. Priorities for optional information categories can be introduced for specific purposes.

In such cases, the mandatory priorities can be extended with a priority for the optional

information category.
Information categories
Mandatory Mandatory Mandatory Mandatory
Mandatory
Level 1 Level 3 Level 4 Priority
Level 2

FULL 1
PERFORMANCE
(IAOGFP)
PARTIAL 2
PERFORMANCE
(IAOGPP)
TECHNICAL 3
STANDBY
(IAONGTS)
OUT OF 4
ENVIRONMENTAL
SPECIFICATION
(IAONGEN)
5
REQUESTED
SHUTDOWN
(IAONGRS)
OUT OF 6
ELECTRICAL
SPECIFICATION
(IAONGEL)

SCHEDULED MAINTENANCE 7
(IANOSM)
8
PLANNED CORRECTIVE ACTION
(IANOPCA)
FORCED OUTAGE 9
(IANOFO)
SUSPENDED 10
(IANOS)
FORCE MAJEURE 11
(IAFM)
INFORMATION UNAVAILABLE 12
(IU)
Figure 2 – Information category priority
INFORMATION AVAILABLE
(IA)
NON-OPERATIVE
OPERATIVE
(IANO)
(IAO)


NON-GENERATING GENERATING
(IAONG) (IAOG)

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5 INFORMATION AVAILABLE


Definition – The category INFORMATION AVAILABLE covers all time periods during which

information on the WTGS and external conditions is retrieved, logged and stored manually or

automatically.


It is recognised that there may be circumstances where information is partially available.

Qualification for INFORMATION AVAILABLE category requires enough information to confirm

if the exit and entry points for all mandatory categories are
...