SIST EN IEC 62934:2021

SLOVENSKI STANDARD
SIST EN IEC 62934:2021
01-september-2021
Integracija omrežja proizvodnje energije iz obnovljivih virov - Izrazi in definicije
Grid integration of renewable energy generation - Terms and definitions
Netzintegration erneuerbarer Energieerzeugung - Begriffe, Definitionen und Symbole
Intégration de la production d’énergie renouvelable aux réseaux électriques - Termes et
définitions
Ta slovenski standard je istoveten z: EN IEC 62934:2021
ICS:
27.010 Prenos energije in toplote na Energy and heat transfer
splošno engineering in general
SIST EN IEC 62934:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN IEC 62934:2021

---------------------- Page: 2 ----------------------
SIST EN IEC 62934:2021


EUROPEAN STANDARD EN IEC 62934

NORME EUROPÉENNE

EUROPÄISCHE NORM
June 2021
ICS 27.010; 29.020

English Version
Grid integration of renewable energy generation - Terms and
definitions
(IEC 62934:2021)
Intégration de la production d'énergie renouvelable aux Netzintegration erneuerbarer Energieerzeugung - Begriffe,
réseaux électriques - Termes et définitions Definitionen und Symbole
(IEC 62934:2021) (IEC 62934:2021)
This European Standard was approved by CENELEC on 2021-05-31. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 62934:2021 E

---------------------- Page: 3 ----------------------
SIST EN IEC 62934:2021
EN IEC 62934:2021 (E)
European foreword
The text of document 8A/75/FDIS, future edition 1 of IEC 62934, prepared by SC 8A "Grid Integration
of Renewable Energy Generation" of IEC/TC 8 "System aspects of electrical energy supply" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 62934:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-02-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-05-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 62934:2021 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61400-21-1:2019 NOTE Harmonized as EN IEC 61400-21-1:2019 (not modified)
IEC 61400-27-1:2020 NOTE Harmonized as EN IEC 61400-27-1:2020 (not modified)
IEC 61400-27-2:2020 NOTE Harmonized as EN IEC 61400-27-2:2020 (not modified)


2

---------------------- Page: 4 ----------------------
SIST EN IEC 62934:2021




IEC 62934

®


Edition 1.0 2021-04




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Grid integration of renewable energy generation – Terms and definitions



Intégration de la production d’énergie renouvelable aux réseaux électriques –

Termes et définitions

















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.010; 29.020 ISBN 978-2-8322-9621-9




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 5 ----------------------
SIST EN IEC 62934:2021
– 2 – IEC 62934:2021 © IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
3.1 Terms and definitions for renewable energy generation . 6
3.2 Terms and definitions for grid aspects and requirements. 8
3.3 Terms and definitions for modelling, analysis and planning . 15
3.4 Terms and definitions for control and protection . 17
3.5 Terms and definitions for forecasting . 20
3.6 Terms and definitions for grid compliance test and assessment . 21
3.7 Terms and definitions for scheduling, dispatching and market . 22
3.8 Miscellaneous terms and definitions . 25
4 Acronyms and abbreviations . 27
Annex A (informative) Illustration of unit, plant, cluster and kinds of points . 28
Index of terms . 32
Bibliography . 37

Figure 1 – Examples of basic electronic power converters . 26
Figure A.1 – Typical forms of renewable energy generating units . 28
Figure A.2 – Typical forms of renewable energy power plants . 30
Figure A.3 – Cluster of renewable energy power plants . 31

---------------------- Page: 6 ----------------------
SIST EN IEC 62934:2021
IEC 62934:2021 © IEC 2021 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

GRID INTEGRATION OF RENEWABLE ENERGY GENERATION –
TERMS AND DEFINITIONS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 62934 has been prepared by subcommittee 8A: Grid Integration of Renewable Energy
Generation, of IEC technical committee 8: System aspects of electrical energy supply. It is an
International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
8A/75/FDIS 8A/79/RVD

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.

---------------------- Page: 7 ----------------------
SIST EN IEC 62934:2021
– 4 – IEC 62934:2021 © IEC 2021
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

---------------------- Page: 8 ----------------------
SIST EN IEC 62934:2021
IEC 62934:2021 © IEC 2021 – 5 –
INTRODUCTION
The purpose of this terminology document is to provide terms and definitions for all publications
under the responsibility of SC 8A. In this document, renewable energy generation is the electric
power generation which uses renewable energy as its primary source for the conversion into
electricity.
All SC 8A normative documents to be published should keep consistency with this International
Standard (IS). This IS will be revised together with other SC 8A publications in order to avoid
mismatches when necessary.
From the technical point of view, grid integration of renewable energy generation is a
interdisciplinary complex technical field which is concerned with basic equipment, system
integration, control and protection, operation and dispatch, market and trade and so on. Without
a strong standardization of terminology, focal terms can have a different understanding by
different countries, parties, and technical areas. Harmonised vocabulary is critical also from the
market point of view. It impacts economics and this can become a barrier to commerce. The
correct comparison among different options is fundamental, therefore basic terms and
definitions impact economic decisions.
Several IEC product standards give definitions of certain terms which are necessary for the
understanding of how to design, manufacture and use of those products. The International
Electrotechnical Vocabulary (IEV, IEC 60050, http://www.electropedia.org) and the IEC
Glossary (http://std.iec.ch/glossary) allow on-line access to this information.
Terms and definitions of this document have been harmonized with the IEV, the IEC Glossary
and other IEC documents as far as possible. Definitions not included in this terminology
standard may be found elsewhere in other IEC documents.
The use of abbreviations has been optimized, on the one hand to avoid tedious repetition and,
on the other hand, to avoid confusion. A minimum set of abbreviations is identified in Clause 4
of this document; the other terms are written out in full spelling when needed.

---------------------- Page: 9 ----------------------
SIST EN IEC 62934:2021
– 6 – IEC 62934:2021 © IEC 2021
GRID INTEGRATION OF RENEWABLE ENERGY GENERATION –
TERMS AND DEFINITIONS



1 Scope
This terminology document provides terms and definitions in the subject area of grid integration
of renewable energy generation. The technical issues of grid integration mainly focus on the
issues caused by renewable energy generation with variable sources and/or converter based
technology, such as wind power and photovoltaic power generation. Some renewable energy
generations such as hydro power and biomass power with a relatively continuously available
primary energy source and a rotating generator are conventional sources of generation, and
are therefore not covered in this document.
The intention of this document is to answer the question "what do the words mean" and not
"under what conditions do the terms apply".
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions for renewable energy generation
3.1.1
renewable energy
RE
primary energy, the source of which is constantly replenished and will not become depleted
Note 1 to entry: Examples of renewable energy are: wind, solar, geothermal, hydropower, etc.
Note 2 to entry: Fossil fuels are non renewable.
[SOURCE: IEC 60050-617:2009, 617-04-11 modified, examples of renewable energy are added
in Note 1 to entry.”]
3.1.2
variable renewable energy
VRE
subset of renewable energy, the source of which is not continuously available and cannot be
stored or controlled
EXAMPLE Wind energy, solar energy, wave energy.

---------------------- Page: 10 ----------------------
SIST EN IEC 62934:2021
IEC 62934:2021 © IEC 2021 – 7 –
3.1.3
renewable energy generation
generation of electrical energy, which uses renewable energy as the primary energy source for
the conversion into electricity
3.1.4
variable renewable energy generation
subset of renewable energy generation, which uses variable renewable energy as the primary
energy source for the conversion into electricity
EXAMPLE Wind power generation, photovoltaic power generation, concentrated solar power generation, wave
power generation.
Note 1 to entry: The primary energy from variable renewable energy sources is in most cases not able to be stored
and therefore the electricity generated is constrained by the availability of the energy source.
3.1.5
renewable energy generating unit
REGU
smallest set of equipment which can generate electricity from renewable energy and can feed
the electricity into an electric power network
Note 1 to entry: Several typical forms of renewable energy generating unit are shown in Annex A.
3.1.6
renewable energy power plant
collection of renewable energy generating units connected to an electric power network through
one or more points of connection, including auxiliaries and connection equipment
Note 1 to entry: Two typical forms of renewable energy power plant are shown in Annex A.
3.1.7
power collection system
electrical system that collects the electricity from at least one
renewable energy generating unit and feeds this electricity into an electric power network,
usually comprising transformers and overhead lines or cables
3.1.8
substation
plant substation
transformer substation or switching substation of a renewable
energy power plant through which the output power of all generating units is transmitted to the
electric power network
3.1.9
point of generating unit connection
PGUC
point that is part of the generating unit and identified by the manufacturer as a reference point
at which the generating unit is connected to the power collection system
3.1.10
point of connection
POC
reference point on the electric power network where the user’s electrical facility is connected
[SOURCE: IEC 60050-617:2009, 617-04-01]

---------------------- Page: 11 ----------------------
SIST EN IEC 62934:2021
– 8 – IEC 62934:2021 © IEC 2021
3.1.11
point of common coupling
PCC
point in an electric power system, electrically nearest to a particular load or the POC of a power
plant, at which other loads/power plants are, or may be, connected
Note 1 to entry: These loads can be either devices, equipment or systems, or distinct customer's installations.
[SOURCE: IEC 60050-614:2016, 614-01-12, modified – "or the POC of a power plant" is added
and "network users' installations" is changed to "customer's installations"]
3.1.12
cluster
two or more neighboring renewable energy power plants which
are connected to the electric power network via a common substation
Note 1 to entry: Typical form of cluster is shown in Annex A.
3.1.13
distributed energy resources
DER
generators (with their auxiliaries, protection and connection equipment), including loads having
a generating mode (such as electrical energy storage systems), connected to a low-voltage or
a medium-voltage network
[SOURCE: IEC 60050-617:2017,617-04-20]
3.1.14
distributed generation
DG
generation of electric energy by multiple sources which are connected to the power distribution
system
[SOURCE: IEC-60050-617:2009, 617-04-09]
3.1.15
virtual power plant
VPP
group of distributed energy resources and controllable loads which combine to function as a
dispatchable unit
Note 1 to entry: A virtual power plant can be used for the purpose of participating in the electricity market or
aggregating ancillary services.
[SOURCE: IEC 60050-617:2017, 617-04-27, modified − controllable loads are included in the
definition since they form an essential part of virtual power plant]
3.2 Terms and definitions for grid aspects and requirements
3.2.1
power system
3.2.1.1
electric power system
electricity supply system
< broad sense> all installations and plant provided for the purpose of generating, transmitting
and distributing electricity
[SOURCE: IEC 60050-601:1985, 601-01-01]

---------------------- Page: 12 ----------------------
SIST EN IEC 62934:2021
IEC 62934:2021 © IEC 2021 – 9 –
3.2.1.2
electric power network
particular installations, substations, lines or cables for the transmission and distribution of
electricity
Note 1 to entry: The boundaries of the different parts of this network are defined by appropriate criteria, such as
geographical situation, ownership, voltage, etc.
[SOURCE: IEC 60050-601:1985, 601-01-02]
3.2.1.3
bulk power system
BPS
bulk electricity system
portion of the electric power system comprising the facilities used for the generation and
transmission of electric energy
Note 1 to entry: The extent of the bulk power system is usually limited to the means for production and transmission
of electric energy to major industrial and distribution centers.
Note 2 to entry: In English, the term "composite system" is also used for this concept.
[SOURCE: IEC 60050-601:1985, 601-01-33]
3.2.2
electrical quantities
3.2.2.1
nominal voltage
U
n
value of the voltage (line to line) by which a power plant is designated and
identified, usually defined at the POC
[SOURCE: IEC 60050-826:2004, 826-11-01, modified − supplementary information is added to
indicate that the nominal voltage of a power plant is usually defined at the point of connection]
3.2.2.2
rated power
rated active power
maximum continuous power output which a renewable energy generating unit or plant is
designed to achieve under normal operating conditions
Note 1 to entry: In some standards and grid codes this term is referred as "rated capacity".
[SOURCE: IEC 60050-415:1999, 415-04-03, modified – "wind turbine" is changed to "renewable
energy generating unit or plant" to adapt the scope of this standard]
3.2.2.3
nominal active power
P
n
nominal value of the active power generation of a renewable energy generating unit or power
plant, which must be stated by the manufacturer or the designer
Note 1 to entry: It is used as a base for calculating quantities in relation to that generating unit or power plant.
3.2.2.4
nominal apparent power
S
n
apparent power from a renewable energy generating unit or power plant while operating at
nominal current and nominal voltage and frequency within the maximum permissible reactive
power

---------------------- Page: 13 ----------------------
SIST EN IEC 62934:2021
– 10 – IEC 62934:2021 © IEC 2021
Note 1 to entry:
S = 3UI (1)
n nn
3.2.2.5
nominal current
I
n
nominal value of the current from a renewable energy generating unit or power plant, which
must be calculated from nominal active power and nominal voltage at specified or designed
power factor
Note 1 to entry:
P
n
 (2)
I =
n
3U ⋅ PF
n
3.2.2.6
registered power
active/apparent power of a power plant registered by the plant owner at the network operator's
or regulator's registry
3.2.2.7
active power ramp rate
rate of change of active power during a specified period
3.2.3
type of generator
3.2.3.1
synchronous machine type of generator
generating unit connected to an electric power network via a synchronous generator
3.2.3.2
asynchronous machine type of generator
generating unit connected to an electric power network via an asynchronous generator
3.2.3.3
converter type of generator
generating unit connected to an electric power network via a power electronic converter
3.2.4
short-circuit
accidental or intentional conductive path between two or more conductive parts forcing the
electric potential differences between these conductive parts to be equal or close to zero
[SOURCE: IEC 60050-614:2016, 614-02-02]
3.2.5
short-circuit current
I
k
current that a renewable energy power plant delivers to the
point of connection resulting from a short-circuit in the external electric power system

---------------------- Page: 14 ----------------------
SIST EN IEC 62934:2021
IEC 62934:2021 © IEC 2021 – 11 –
3.2.6
short-circuit power
S
k
the product of the current in the short-circuit at a point of a system and a conventional voltage,
generally the operating voltage
Note 1 to entry: Using physical units for line current (A) and nominal voltage (V), the product should also include
the factor √3.
[SOURCE: IEC 60050-601:1985, 601-01-14, modified − Note 1 to entry is added]
3.2.7
short-circuit ratio
SCR
ratio of the three-phase short-circuit power at POC/PGUC to the nominal active power of a
renewable energy power plant or generating unit
Note 1 to entry: SCR is a common analytical indicator used in the industry to quantify system strength.
Note 2 to entry: There is no industry consensus on the exact definition and methodology for calculating the SCR,
particularly for applications with several adjacent renewable energy power plants, or for a renewable energy power
plant adjacent to HVDC terminals, see CIGRE TB 671.
3.2.8
weighted short-circuit ratio
WSCR
index based on short-circuit ratio to assist in defining operational limits for total
transmission of active power from inverter-based generators across key power system
interfaces
Note 1 to entry:
N
SP⋅
∑ knii
i=1
WSCR=  (3)
2
N
P
(∑ )
ni
i=1
Note 2 to entry: S is the short-circuit power at bus i without current contribution from renewable energy power
ki
plants, P is the nominal power of renewable energy power plant to be connected at bus i, N is the number of power
ni
plants fully interacting with each other, i is the summation index of the renewable energy power plants.
3.2.9
composite short-circuit ratio
CSCR
index based on short-circuit ratio, which calculates an aggregate SCR for multiple renewable
energy power plants by creating a common bus and tying all renewable energy power plants of
interest together at that common bus
Note 1 to entry:
S
kv
CSCR= (4)
N
P
∑
ni
i=1
Note 2 to entry: S is the short-circuit power at the virtual common bus without current contribution from the
kv
renewable energy power plants. P is the nominal power of renewable energy power plant i, N is the number of
ni
renewable energy power plants to be considered.
Note 3 to entry: Composite short-circuit ratio is used to estimate the equivalent system impedance seen by multiple
renewable energy power plants.

---------------------- Page: 15 ----------------------
SIST EN IEC 62934:2021
– 12 – IEC 62934:2021 © IEC 2021
3.2.10
short-circuit ratio with interaction factors
SCRIF
index based on short circuit ratio, which considers interaction voltage sensitivity between
electrically close renewable energy power plants
Note 1 to entry:
S
ki
SCRIF= (5)
i
P + IF ⋅P
( )
nni ∑ ji j
jj()≠i
Note 2 to entry: S is the short-circuit power at the POC of renewable energy power plant i without current
ki
contribution from the other renewable energy power plants, P is the nominal power of renewable energy power plant
ni
i, IF is the voltage change at bus j (ΔU ) for a voltage change at bus i (ΔU ), as follows:
ji j i
∆U
j
IF =  (6)
ji
∆U
i
Note 3 to entry: SCRIF is proposed to capture the voltage change at one bus resulting from a voltage change at
another bus. When multiple renewable energy power plants are located very close to each other, they share the grid
strength and short circuit level; hence, the grid strength is actually much lower than the overall short-circuit level
calculated at that bus or buses.
3.2.11
power quality
characteristics of the electric current, voltage and frequencies at a given point in an electric
power system, evaluated against a set of reference technical parameters
Note 1 to entry: These parameters might, in some cases, relate to the compatibility between electricity supplied in
an electric power system and the loads connected to that electric power system.
[SOURCE: IEC 60050-617:2009, 617-01-05]
3.2.12
harmonic
harmonic component
sinusoidal component of the Fourier series of a periodic quantity, the harmonic order of which
is an integer number greater than one
th
Note 1 to entry: A component of harmonic order n (with n > 1) is generally designated "n harmonic". The
st
designation of the fundamental component as the "1 harmonic" is not recommended.
[SOURCE: IEC 60050-103:2009, 103-07-25]
3.2.13
interharmonic component
sinusoidal component of the Fourier series of a periodic quantity the harmonic order of which
is a non-integer rational number
Not
...