SIST EN 50549-2:2019
(Main)Requirements for generating plants to be connected in parallel with distribution networks - Part 2: Connection to a MV distribution network - Generating plants up to and including Type B
Requirements for generating plants to be connected in parallel with distribution networks - Part 2: Connection to a MV distribution network - Generating plants up to and including Type B
This standard provides technical requirements for the connection of generating plants up to and including Type B which can be operated in parallel with a public MV distribution network. They are intended to be used as a technical reference for connection agreements between DSOs and electricity producers and to demonstrate compliance with COMMISSION REGULATION (EU) 2016/631 (Requirements for Generators).
Anforderungen für zum Parallelbetrieb mit einem Verteilnetz vorgesehene Erzeugungsanlagen – Teil 2: Anschluss an das Mittelspannungsverteilnetz für Erzeugungsanlagen bis einschließlich Typ B
Exigences relatives aux centrales électriques destinées à être raccordées en parallèle à des réseaux de distribution - Partie 2: Raccordement à un réseau de distribution MT - Centrales électriques jusqu’au Type B inclus
Zahteve za vzporedno vezavo generatorskih postrojev z razdelilnim omrežjem - 2. del: Vezava s srednjenapetostnim razdelilnim omrežjem do vključno tipa B
Ta standard podaja tehnične zahteve za povezovanje generatorskih postrojev do vključno tipa B, ki jih je mogoče upravljati vzporedno z javnim srednjenapetostnim razdelilnim omrežjem. Namen njihove uporabe je tehnična referenca za dogovore o priključku med upravljavci razdelilnih omrežij in proizvajalci električne energije ter izkazovanje skladnosti z UREDBO KOMISIJE (EU) 2016/631 (Zahteve za generatorje).
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 50549-2:2019
01-april-2019
Nadomešča:
SIST-TS CLC/TS 50549-2:2015
Zahteve za vzporedno vezavo generatorskih postrojev z razdelilnim omrežjem - 2.
del: Vezava s srednjenapetostnim razdelilnim omrežjem do vključno tipa B
Requirements for generating plants to be connected in parallel with distribution networks
- Part 2: Connection to a MV distribution network - Generating plants up to and including
Type B
Anforderungen für zum Parallelbetrieb mit einem Verteilnetz vorgesehene
Erzeugungsanlagen – Teil 2: Anschluss an das Mittelspannungsverteilnetz für
Erzeugungsanlagen bis einschließlich Typ B
Exigences relatives aux centrales électriques destinées à être raccordées en parallèle à
des réseaux de distribution - Partie 2: Raccordement à un réseau de distribution MT -
Centrales électriques jusqu’au Type B inclus
Ta slovenski standard je istoveten z: EN 50549-2:2019
ICS:
29.160.20 Generatorji Generators
29.240.01 Omrežja za prenos in Power transmission and
distribucijo električne energije distribution networks in
na splošno general
SIST EN 50549-2:2019 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50549-2:2019
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SIST EN 50549-2:2019
EUROPEAN STANDARD EN 50549-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2019
ICS 29.160.20 Supersedes CLC/TS 50549-2:2015
English Version
Requirements for generating plants to be connected in parallel
with distribution networks - Part 2: Connection to a MV
distribution network - Generating plants up to and including Type
B
Exigences relatives aux centrales électriques destinées à Anforderungen für zum Parallelbetrieb mit einem Verteilnetz
être raccordées en parallèle à des réseaux de distribution - vorgesehene Erzeugungsanlagen - Teil 2: Anschluss an
Partie 2: Raccordement à un réseau de distribution MT - das Mittelspannungsverteilnetz für Erzeugungsanlagen bis
Centrales électriques jusqu'au Type B inclus einschließlich Typ B
This European Standard was approved by CENELEC on 2018-08-09. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, 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
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50549-2:2019 E
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
Contents Page
European foreword . 4
Introduction. 5
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
3.1 General . 8
3.2 Plant, module and unit . 10
3.3 Power . 12
3.4 Voltage . 13
3.5 Circuit theory . 15
3.6 Protection . 17
3.7 Control . 21
4 Requirements on generating plants . 23
4.1 General . 23
4.2 Connection scheme . 24
4.3 Choice of switchgear . 24
4.3.1 General . 24
4.3.2 Interface switch . 24
4.4 Normal operating range . 25
4.4.1 General . 25
4.4.2 Operating frequency range . 25
4.4.3 Minimal requirement for active power delivery at underfrequency . 25
4.4.4 Continuous operating voltage range . 26
4.5 Immunity to disturbances . 26
4.5.1 General . 26
4.5.2 Rate of change of frequency (ROCOF) immunity . 27
4.5.3 Under-voltage ride through (UVRT) . 27
4.5.4 Over-voltage ride through (OVRT) . 29
4.6 Active response to frequency deviation . 30
4.6.1 Power response to overfrequency . 30
4.6.2 Power response to underfrequency. 33
4.7 Power response to voltage changes . 36
4.7.1 General . 36
4.7.2 Voltage support by reactive power . 36
4.7.3 Voltage related active power reduction . 41
4.7.4 Short circuit current requirements on generating plants . 41
4.8 EMC and power quality . 46
4.9 Interface protection . 48
4.9.1 General . 48
4.9.2 Voltage transformer . 49
4.9.3 Requirements on voltage and frequency protection . 49
4.9.4 Means to detect island situation . 52
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EN 50549-2:2019 (E)
4.9.5 Digital input to the interface protection . 53
4.10 Connection and starting to generate electrical power. 53
4.10.1 General . 53
4.10.2 Automatic reconnection after tripping . 54
4.10.3 Starting to generate electrical power . 54
4.10.4 Synchronization . 54
4.11 Ceasing and reduction of active power on set point . 55
4.11.1 Ceasing active power . 55
4.11.2 Reduction of active power on set point . 55
4.12 Remote information exchange . 55
Annex A (informative) Interconnection guidance . 56
A.1 General . 56
A.2 Network integration . 56
A.3 Clusters of single-phase generating units . 57
Annex B (informative) Remote information exchange . 58
Annex C (informative) Parameter Table . 62
Annex D (informative) List of national requirements applicable for generating plants . 67
Annex E (informative) Loss of Mains and overall power system security . 69
Annex F (informative) Examples of protection strategies . 70
F.1 Introduction . 70
F.1.1 General . 70
F.1.2 Generalities . 70
F.1.3 Detection of unwanted islands . 70
F.1.4 Problems with uncontrolled islanding in MV networks . 71
F.1.4.1 Safety . 71
F.1.4.2 Grid parameters . 71
F.1.4.3 Reclosing operations . 71
F.1.4.4 Protection of islands against overcurrents . 71
F.1.4.5 Protection against phase to earth faults . 71
F.2 Example strategy 1 . 72
F.3 Example strategy 2 . 75
Annex G (normative) Abbreviations . 77
Annex H (informative) Relationship between this European standard and the
COMMISSION REGULATION (EU) 2016/631 . 78
Bibliography . 79
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
European foreword
This document (EN 50549-2:2019) has been prepared by CLC/TC 8X “System aspects of electrical
energy supply”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2019-08-01
implemented at national level by publication
of an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2022-02-01
conflicting with this document have to
be withdrawn
This document supersedes CLC/TS 50549-2:2015.
This European Standard relates to both the RfG European Network Code and current technical market
needs. Its purpose is to give detailed description of functions to be implemented in products.
This European Standard is also intended to serve as a technical reference for the definition of national
requirements where the RfG European Network Code requirements allow flexible implementation. The
specified requirements are solely technical requirements; economic issues regarding, e.g. the bearing
of cost are not in the scope of this document.
CLC/TC 8X plans future standardization work in order to ensure the compatibility of this European
Standard (EN) with the evolution of the legal framework.
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.
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
Introduction
1. Foreword
This Explanatory Note explains the rationale behind the content and structure of EN 50549-1 and EN
50549-2. Due to the unique relationship between COMMISSION REGULATION 2016/631 (RfG) and
the EN 50549 Series, and based on the comments received at the enquiry stage of FprEN 50549-1
and FprEN 50549-2, TC8X WG03 decided to draft this explanatory note in order to provide national
committees and the wider public with an understanding of these rationale
2. Increased Scope of EN 50549 in relation to RfG
In the tradition of EN 50438, TC8X WG03 intended, in writing of FprEN 50549, to include all
capabilities of generating plants that are needed to operate these in parallel to distribution networks.
This includes issues necessary for a stable distribution network management as well as the
management of the interconnected system. As RfG is focused on the interconnected system, it is
logical that, taking into account further needs for distribution network management, further aspects are
included.
3. Introduction of “Responsible party”
During the national implementation process of COMMISSION REGULATION (EU) 2016/631, different
types of responsible parties play a role in the refinement of the non-exhaustive requirements. In each
member country, the National Regulatory Authority approves this national implementation. Depending
on the national regulatory framework, this might result in a variety of documents: national laws,
decrees or regulations, technical specifications, or requirements of transmission and distribution
system operators. Therefore, as explained in the scope, EN 50549-1 and EN 50549-2 refer to the
“responsible party” where requirements have to be defined by an actor other than the DSO. However
when a generating plant is built and connected to the distribution network, typically the distribution
system operator provides the plant developer all the technical requirements to be fulfilled.
4. Use of terms
Terms and definitions are selected to achieve consistency with EN 60050, IEV (cf.
www.electropedia.org) and CENELEC terminology, recognizing that terms in COMMISSION
REGULATION (EU) 2016/631 may deviate.
5. Additional requirements for distribution system management
The following requirements are stated in EN 50549 for distribution system management reasons,
which might not be required in RfG or if required in RfG, are not required for type A. As Directive
714/2009 8(7) limits the scope of RfG to issues effecting the cross border trade of electricity,
requirements included solely for the need of distribution system management are considered beyond
the scope of RfG.
– Connection scheme and Coordination of switch gear,
– Voltage operating range,
– Reactive power capability and control modes,
– Voltage related active power reduction,
– Interface protection including the detection of island situations,
– Connection and reconnection to the grid,
– Generation curtailment,
– Remote information exchange,
6. Additional requirements for stability of the interconnected system
Additionally, requirements relevant for the stability of the interconnected systems are included in case
of over voltage ride through (OVRT) as this is not dealt with in RfG. Due to the long duration of RfG
development and the fast development of decentralised generation in Europe robustness to voltage
swells is considered to be of high importance, but apparently could not be included into RfG.
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
As electrical energy storage system (EESS), are excluded from the scope of RfG, but are included in
the scope of the EN 50549 Series, EN 50549 also includes the further requirement of active power
frequency response to under frequency (LFSM-U) to electrical energy storage systems. This
requirement is considered of great importance in view of the expected fast increase of electrical
energy storage for the next years and is considered not to affect the cost of electrical energy storage
systems if considered during their design.
7. Details on the operation of the LFSM-O
During the enquiry stage, some comments reported that certain details in the chapter regarding the
operation of the LFSM-O (e.g. intentional delay, operation with deactivation threshold) were violating
the RfG. These topics have been further evaluated consulting the European Stakeholder Committee
(ESC-GC) and TC8X WG03 could not conclude in the same way. The fact that these operations are
not foreseen in the RfG is considered not sufficient to state any violation. Therefore these details are
kept with additional information on their use.
8. Implementation of UVRT and LFSM-U to avoid legal conflict with RfG
Under Voltage Ride Through (UVRT) requirements are defined in RfG for modules type B, type C and
type D. There is no mentioning of this topic for type A modules.
Nevertheless UVRT is seen as an important requirement in some member states even for small
generation modules like type A.
From a legal point of view there are two contradicting opinions on whether it is allowed or forbidden to
require UVRT for type A modules.
– Opinion 1: It can be required because the topic is not dealt with for type A modules.
– Option 2: It cannot be required because the topic UVRT is dealt within the RfG. Not mentioning
UVRT for type A in RfG therefore means that it cannot be required for type A modules.
As long as there is no clarification on this legal issue Cenelec does not have the possibility to require
UVRT for type A modules. This is the reason why in EN 50549-1 and 50549-2 the UVRT
functionalities for type A generating plants are not defined as requirements (shall) but as a
recommendation (should).
This same explanation can be applied to the requirements regarding Limited Frequency Sensitive
Mode - Underfrequency (LFSM-U). In RfG, this LFSM-U is solely defined for type C and type D
modules. In EN 50549, LFSM-U is defined as a recommendation (should) for generating modules of
type A and type B. The sole exception is electrical energy storage systems having a requirement
(shall) but these systems are not within the scope of the RfG.
9. Annex H - Relationship between this European standard and the COMMISSION
REGULATION (EU) 2016/631.
Manufacturers of generating units and plants shall comply with all relevant EU Directives and
Regulations. For the specific function of connecting the generating plant with the electric system the
reference regulation is COMMISSION REGULATION (EU) 2016/631 (NC RfG).
Since the EN 50549-1 and −2 are covering all technical requirements for type A and type B generating
units, modules and plants, it is considered helpful to provide the information which clause of the
standard supports which article of the RfG in a structured informative annex within the standard.
For other EU Directives and Regulations (e.g. LVD, MD or GAR) it is a formal task given to CCMC to
include such an informative Annex ZZ based on a standardization request from the EU. It is finally
reviewed by the new approach consultant (NAC) for the relevant Directive or Regulation, prior to the
listing of the standard in the official journal of the EU (OJEU) providing then “presumption of
conformity”. This means that if a product is compliant with the standard, the Directive or Regulations is
fulfilled too.
CLC TC 8X is fully aware, that this official procedure is not included in the RfG. Therefore CLC TC 8X
WG3 drafted Annex H. In Annex H the relationship between the clauses and the articles is shown. It is
considered, that generating plants compliant with the clauses of the standards are also compliant with
the articles in the RfG. Of course, this does not provide “presumption of conformity” as a listed
standard in the OJEU would provide. Nevertheless it will be helpful for the industry when performing
the conformity assessment against RfG.
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
1 Scope
This document specifies the technical requirements for the protection functions and the operational
capabilities for generating plants, intended to operate in parallel with MV distribution networks.
For practical reasons this document refers to the responsible party where requirements have to be
defined by an actor other than the DSO, e.g. TSO, member state, regulatory authorities according to
the legal framework. Typically the DSO will inform the producer about these requirements.
NOTE 1 This includes European network codes and their national implementation, as well as additional
national regulations.
NOTE 2 Additional national requirements especially for the connection to the distribution network and the
operation of the generating plant may apply.
The requirements of this document apply, irrespective of the kind of energy source and irrespective of
the presence of loads in the producer’s network, to generating plants, generating modules, electrical
machinery and electronic equipment that meet all of the following conditions:
– converting any energy source into AC electricity;
– generating modules capacity of type B or smaller according to COMMISSION REGULATION (EU)
2016/631 while considering national implementation for the decision regarding power limits
between A and B types and B and C types;
– connected to and operated in parallel with an AC MV distribution network.
NOTE 3 Generating plants connected to a LV distribution network fall into the scope of EN 50549-1.
NOTE 4 Electrical energy storage systems (EESS) in meeting the conditions above are included
If generating modules of different type (A or B) are combined in one plant, different requirements apply
for the different modules based on the type of each module.
EXAMPLE: If a generating plant consists of multiple generating modules (see 3.2.1), according to
COMMISSION REGLUATION (EU) 2016/631 the situation might occur, that some generating modules
are of type A and some are of type B.
Unless specified otherwise by the DSO and the responsible party, generating plants with a maximum
apparent power up to 150 kVA can, as alternative to the requirements of this document, comply with
EN 50549-1. A different threshold may be defined by the DSO and the responsible party.
This document recognizes the existence of specific technical requirements (e.g. grid codes) of the
DSO or another responsible party within a member state and these must be complied with.
Excluded from the scope are:
• the selection and evaluation of the point of connection;
• power system impact assessment e.g. assessment of effects on power quality, local voltage
increase, impact on line protections operation;
• connection assessment, the set of technical verifications made as part of the planning of the
connection;
• island operation of generating plants, both intentional and unintentional, where no part of the
distribution network is involved;
• four-quadrant rectifier of drives feeding breaking energy back into the distribution network for
limited duration with no internal source of primary energy;
• uninterruptible power supply with duration of parallel operation limited to 100 ms;
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
NOTE 5 Parallel operation due to maintenance of uninterruptible power supply units is not seen as part of
normal UPS operation and therefore not considered in this EN.
• requirements for the safety of personnel as they are already adequately covered by existing
European Standards.
• the connection of a generating unit, module or plant into a DC network
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
EN 60044-2, Instrument transformers — Part 2: Inductive voltage transformers (IEC 60044-2)
EN 60044-7, Instrument transformers — Part 7: Electronic voltage transformers (IEC 60044-7)
EN 60255-127, Measuring relays and protection equipment — Part 127: Functional requirements for
over/under voltage protection (IEC 60255-127)
EN 61000-4-30, Electromagnetic compatibility (EMC) — Part 4-30: Testing and measurement
techniques — Power quality measurement methods (IEC 61000-4-30)
EN 61869-3, Instrument transformers — Part 3: Additional requirements for inductive voltage
transformers (IEC 61869-3)
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
Note: Terms and definitions are selected to achieve consistency with IEV (cf. www.electropedia.org)
and CENELEC terminology, recognizing that terms in COMMISSION REGULATION (EU) 2016/631
may deviate.
3.1 General
3.1.1
distribution network
AC electrical network, including closed distribution networks, for the distribution of electrical power
from and to third parties connected to it, to and from a transmission or another distribution network, for
which a DSO is responsible
Note 1 to entry: A distribution network does not include the producer’s network
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
3.1.2
closed distribution network
system which distributes electricity within an industrial, commercial or shared services site, that is
geographically confined, and does not supply households customers (without excluding the option of a
small number of households served by the system that have an employment or similar associations
with the owner of the system)
Note 1 to entry: A closed distribution network will either be used to integrate the production processes of the
network users for specific or technical reasons or distribute electricity primarily to the operator of the closed
distribution network or his related undertakings
[SOURCE: Directive 2009/72/EC, article 28, modified]
3.1.3
distribution system operator
DSO
natural or legal person responsible for the distribution of electrical power to final customers and for
operating, ensuring the maintenance of and, if necessary, developing the distribution network in a
given area
Note 1 to entry: As this document is applicable to distribution grids, DSO is used for relevant system operator
according to article 2 (13) of COMMISSION REGULATION 2016/631.
Note 2 to entry: In some countries, the distribution network operator (DNO) fulfils the role of the DSO.
3.1.4
transmission system operator
natural or legal person responsible for operating, ensuring the maintenance of and, if necessary,
developing the transmission system in a given area and, where applicable, its interconnections with
other power systems, and for ensuring the long-term ability of the power system to meet reasonable
demands for the transmission of electricity
3.1.5
responsible
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SLOVENSKI STANDARD
SIST EN 50549-2:2019
01-april-2019
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Requirements for generating plants to be connected in parallel with distribution networks
- Part 2: Connection to a MV distribution network - Generating plants up to and including
Type B
Anforderungen für zum Parallelbetrieb mit einem Verteilnetz vorgesehene
Erzeugungsanlagen – Teil 2: Anschluss an das Mittelspannungsverteilnetz für
Erzeugungsanlagen bis einschließlich Typ B
Exigences relatives aux centrales électriques destinées à être raccordées en parallèle à
des réseaux de distribution - Partie 2: Raccordement à un réseau de distribution MT -
Centrales électriques jusqu’au Type B inclus
Ta slovenski standard je istoveten z: EN 50549-2:2019
ICS:
29.160.20 Generatorji Generators
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
SIST EN 50549-2:2019 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50549-2:2019
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SIST EN 50549-2:2019
EUROPEAN STANDARD EN 50549-2
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2019
ICS 29.160.20 Supersedes CLC/TS 50549-2:2015
English Version
Requirements for generating plants to be connected in parallel
with distribution networks - Part 2: Connection to a MV
distribution network - Generating plants up to and including Type
B
Exigences relatives aux centrales électriques destinées à Anforderungen für zum Parallelbetrieb mit einem Verteilnetz
être raccordées en parallèle à des réseaux de distribution - vorgesehene Erzeugungsanlagen - Teil 2: Anschluss an
Partie 2: Raccordement à un réseau de distribution MT - das Mittelspannungsverteilnetz für Erzeugungsanlagen bis
Centrales électriques jusqu'au Type B inclus einschließlich Typ B
This European Standard was approved by CENELEC on 2018-08-09. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, 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
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50549-2:2019 E
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SIST EN 50549-2:2019
EN 50549-2:2019 (E)
Contents Page
European foreword . 4
Introduction. 5
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
3.1 General . 8
3.2 Plant, module and unit . 10
3.3 Power . 12
3.4 Voltage . 13
3.5 Circuit theory . 15
3.6 Protection . 17
3.7 Control . 21
4 Requirements on generating plants . 23
4.1 General . 23
4.2 Connection scheme . 24
4.3 Choice of switchgear . 24
4.3.1 General . 24
4.3.2 Interface switch . 24
4.4 Normal operating range . 25
4.4.1 General . 25
4.4.2 Operating frequency range . 25
4.4.3 Minimal requirement for active power delivery at underfrequency . 25
4.4.4 Continuous operating voltage range . 26
4.5 Immunity to disturbances . 26
4.5.1 General . 26
4.5.2 Rate of change of frequency (ROCOF) immunity . 27
4.5.3 Under-voltage ride through (UVRT) . 27
4.5.4 Over-voltage ride through (OVRT) . 29
4.6 Active response to frequency deviation . 30
4.6.1 Power response to overfrequency . 30
4.6.2 Power response to underfrequency. 33
4.7 Power response to voltage changes . 36
4.7.1 General . 36
4.7.2 Voltage support by reactive power . 36
4.7.3 Voltage related active power reduction . 41
4.7.4 Short circuit current requirements on generating plants . 41
4.8 EMC and power quality . 46
4.9 Interface protection . 47
4.9.1 General . 47
4.9.2 Voltage transformer . 48
4.9.3 Requirements on voltage and frequency protection . 48
4.9.4 Means to detect island situation . 51
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4.9.5 Digital input to the interface protection . 52
4.10 Connection and starting to generate electrical power. 52
4.10.1 General . 52
4.10.2 Automatic reconnection after tripping . 53
4.10.3 Starting to generate electrical power . 53
4.10.4 Synchronization . 53
4.11 Ceasing and reduction of active power on set point . 54
4.11.1 Ceasing active power . 54
4.11.2 Reduction of active power on set point . 54
4.12 Remote information exchange . 54
Annex A (informative) Interconnection guidance . 55
A.1 General . 55
A.2 Network integration . 55
A.3 Clusters of single-phase generating units . 56
Annex B (informative) Remote information exchange . 57
Annex C (informative) Parameter Table . 63
Annex D (informative) List of national requirements applicable for generating plants . 68
Annex E (informative) Loss of Mains and overall power system security . 70
Annex F (informative) Examples of protection strategies . 71
F.1 Introduction . 71
F.1.1 General . 71
F.1.2 Generalities . 71
F.1.3 Detection of unwanted islands . 71
F.1.4 Problems with uncontrolled islanding in MV networks . 72
F.1.4.1 Safety . 72
F.1.4.2 Grid parameters . 72
F.1.4.3 Reclosing operations . 72
F.1.4.4 Protection of islands against overcurrents . 72
F.1.4.5 Protection against phase to earth faults . 72
F.2 Example strategy 1 . 72
F.3 Example strategy 2 . 76
Annex G (normative) Abbreviations . 78
Annex H (informative) Relationship between this European standard and the
COMMISSION REGULATION (EU) 2016/631 . 79
Bibliography . 80
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European foreword
This document (EN 50549-2:2019) has been prepared by CLC/TC 8X “System aspects of electrical
energy supply”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2019-08-01
implemented at national level by publication
of an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2022-02-01
conflicting with this document have to
be withdrawn
This document supersedes CLC/TS 50549-2:2015.
This European Standard relates to both the RfG European Network Code and current technical market
needs. Its purpose is to give detailed description of functions to be implemented in products.
This European Standard is also intended to serve as a technical reference for the definition of national
requirements where the RfG European Network Code requirements allow flexible implementation. The
specified requirements are solely technical requirements; economic issues regarding, e.g. the bearing
of cost are not in the scope of this document.
CLC/TC 8X plans future standardization work in order to ensure the compatibility of this European
Standard (EN) with the evolution of the legal framework.
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.
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Introduction
1. Foreword
This Explanatory Note explains the rationale behind the content and structure of EN 50549-1 and EN
50549-2. Due to the unique relationship between COMMISSION REGULATION 2016/631 (RfG) and
the EN 50549 Series, and based on the comments received at the enquiry stage of FprEN 50549-1 and
FprEN 50549-2, TC8X WG03 decided to draft this explanatory note in order to provide national
committees and the wider public with an understanding of these rationale
2. Increased Scope of EN 50549 in relation to RfG
In the tradition of EN 50438, TC8X WG03 intended, in writing of FprEN 50549, to include all capabilities
of generating plants that are needed to operate these in parallel to distribution networks. This includes
issues necessary for a stable distribution network management as well as the management of the
interconnected system. As RfG is focused on the interconnected system, it is logical that, taking into
account further needs for distribution network management, further aspects are included.
3. Introduction of “Responsible party”
During the national implementation process of COMMISSION REGULATION (EU) 2016/631, different
types of responsible parties play a role in the refinement of the non-exhaustive requirements. In each
member country, the National Regulatory Authority approves this national implementation. Depending
on the national regulatory framework, this might result in a variety of documents: national laws, decrees
or regulations, technical specifications, or requirements of transmission and distribution system
operators. Therefore, as explained in the scope, EN 50549-1 and EN 50549-2 refer to the “responsible
party” where requirements have to be defined by an actor other than the DSO. However when a
generating plant is built and connected to the distribution network, typically the distribution system
operator provides the plant developer all the technical requirements to be fulfilled.
4. Use of terms
Terms and definitions are selected to achieve consistency with EN 60050, IEV (cf.
www.electropedia.org) and CENELEC terminology, recognizing that terms in COMMISSION
REGULATION (EU) 2016/631 may deviate.
5. Additional requirements for distribution system management
The following requirements are stated in EN 50549 for distribution system management reasons, which
might not be required in RfG or if required in RfG, are not required for type A. As Directive 714/2009
8(7) limits the scope of RfG to issues effecting the cross border trade of electricity, requirements included
solely for the need of distribution system management are considered beyond the scope of RfG.
– Connection scheme and Coordination of switch gear,
– Voltage operating range,
– Reactive power capability and control modes,
– Voltage related active power reduction,
– Interface protection including the detection of island situations,
– Connection and reconnection to the grid,
– Generation curtailment,
– Remote information exchange,
6. Additional requirements for stability of the interconnected system
Additionally, requirements relevant for the stability of the interconnected systems are included in case
of over voltage ride through (OVRT) as this is not dealt with in RfG. Due to the long duration of RfG
development and the fast development of decentralised generation in Europe robustness to voltage
swells is considered to be of high importance, but apparently could not be included into RfG.
As electrical energy storage system (EESS), are excluded from the scope of RfG, but are included in
the scope of the EN 50549 Series, EN 50549 also includes the further requirement of active power
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frequency response to under frequency (LFSM-U) to electrical energy storage systems. This
requirement is considered of great importance in view of the expected fast increase of electrical energy
storage for the next years and is considered not to affect the cost of electrical energy storage systems
if considered during their design.
7. Details on the operation of the LFSM-O
During the enquiry stage, some comments reported that certain details in the chapter regarding the
operation of the LFSM-O (e.g. intentional delay, operation with deactivation threshold) were violating
the RfG. These topics have been further evaluated consulting the European Stakeholder Committee
(ESC-GC) and TC8X WG03 could not conclude in the same way. The fact that these operations are not
foreseen in the RfG is considered not sufficient to state any violation. Therefore these details are kept
with additional information on their use.
8. Implementation of UVRT and LFSM-U to avoid legal conflict with RfG
Under Voltage Ride Through (UVRT) requirements are defined in RfG for modules type B, type C and
type D. There is no mentioning of this topic for type A modules.
Nevertheless UVRT is seen as an important requirement in some member states even for small
generation modules like type A.
From a legal point of view there are two contradicting opinions on whether it is allowed or forbidden to
require UVRT for type A modules.
– Opinion 1: It can be required because the topic is not dealt with for type A modules.
– Option 2: It cannot be required because the topic UVRT is dealt within the RfG. Not mentioning UVRT
for type A in RfG therefore means that it cannot be required for type A modules.
As long as there is no clarification on this legal issue Cenelec does not have the possibility to require
UVRT for type A modules. This is the reason why in EN 50549-1 and 50549-2 the UVRT functionalities
for type A generating plants are not defined as requirements (shall) but as a recommendation (should).
This same explanation can be applied to the requirements regarding Limited Frequency Sensitive Mode
- Underfrequency (LFSM-U). In RfG, this LFSM-U is solely defined for type C and type D modules. In
EN 50549, LFSM-U is defined as a recommendation (should) for generating modules of type A and type
B. The sole exception is electrical energy storage systems having a requirement (shall) but these
systems are not within the scope of the RfG.
9. Annex H - Relationship between this European standard and the COMMISSION REGULATION
(EU) 2016/631.
Manufacturers of generating units and plants shall comply with all relevant EU Directives and
Regulations. For the specific function of connecting the generating plant with the electric system the
reference regulation is COMMISSION REGULATION (EU) 2016/631 (NC RfG).
Since the EN 50549-1 and −2 are covering all technical requirements for type A and type B generating
units, modules and plants, it is considered helpful to provide the information which clause of the standard
supports which article of the RfG in a structured informative annex within the standard.
For other EU Directives and Regulations (e.g. LVD, MD or GAR) it is a formal task given to CCMC to
include such an informative Annex ZZ based on a standardization request from the EU. It is finally
reviewed by the new approach consultant (NAC) for the relevant Directive or Regulation, prior to the
listing of the standard in the official journal of the EU (OJEU) providing then “presumption of conformity”.
This means that if a product is compliant with the standard, the Directive or Regulations is fulfilled too.
CLC TC 8X is fully aware, that this official procedure is not included in the RfG. Therefore CLC TC 8X
WG3 drafted Annex H. In Annex H the relationship between the clauses and the articles is shown. It is
considered, that generating plants compliant with the clauses of the standards are also compliant with
the articles in the RfG. Of course, this does not provide “presumption of conformity” as a listed standard
in the OJEU would provide. Nevertheless it will be helpful for the industry when performing the conformity
assessment against RfG.
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1 Scope
This document specifies the technical requirements for the protection functions and the operational
capabilities for generating plants, intended to operate in parallel with MV distribution networks.
For practical reasons this document refers to the responsible party where requirements have to be
defined by an actor other than the DSO, e.g. TSO, member state, regulatory authorities according to the
legal framework. Typically the DSO will inform the producer about these requirements.
NOTE 1 This includes European network codes and their national implementation, as well as additional national
regulations.
NOTE 2 Additional national requirements especially for the connection to the distribution network and the
operation of the generating plant may apply.
The requirements of this document apply, irrespective of the kind of energy source and irrespective of
the presence of loads in the producer’s network, to generating plants, generating modules, electrical
machinery and electronic equipment that meet all of the following conditions:
– converting any energy source into AC electricity;
– generating modules capacity of type B or smaller according to COMMISSION REGULATION (EU)
2016/631 while considering national implementation for the decision regarding power limits
between A and B types and B and C types;
– connected to and operated in parallel with an AC MV distribution network.
NOTE 3 Generating plants connected to a LV distribution network fall into the scope of EN 50549-1.
NOTE 4 Electrical energy storage systems (EESS) in meeting the conditions above are included
If generating modules of different type (A or B) are combined in one plant, different requirements apply
for the different modules based on the type of each module.
EXAMPLE: If a generating plant consists of multiple generating modules (see 3.2.1), according to
COMMISSION REGLUATION (EU) 2016/631 the situation might occur, that some generating modules
are of type A and some are of type B.
Unless specified otherwise by the DSO and the responsible party, generating plants with a maximum
apparent power up to 150 kVA can, as alternative to the requirements of this document, comply with
EN 50549-1. A different threshold may be defined by the DSO and the responsible party.
This document recognizes the existence of specific technical requirements (e.g. grid codes) of the DSO
or another responsible party within a member state and these must be complied with.
Excluded from the scope are:
• the selection and evaluation of the point of connection;
• power system impact assessment e.g. assessment of effects on power quality, local voltage
increase, impact on line protections operation;
• connection assessment, the set of technical verifications made as part of the planning of the
connection;
• island operation of generating plants, both intentional and unintentional, where no part of the
distribution network is involved;
• four-quadrant rectifier of drives feeding breaking energy back into the distribution network for limited
duration with no internal source of primary energy;
• uninterruptible power supply with duration of parallel operation limited to 100 ms;
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NOTE 5 Parallel operation due to maintenance of uninterruptible power supply units is not seen as part of normal
UPS operation and therefore not considered in this EN.
• requirements for the safety of personnel as they are already adequately covered by existing
European Standards.
• the connection of a generating unit, module or plant into a DC network
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 60044-2, Instrument transformers — Part 2: Inductive voltage transformers (IEC 60044-2)
EN 60044-7, Instrument transformers — Part 7: Electronic voltage transformers (IEC 60044-7)
EN 60255-127, Measuring relays and protection equipment — Part 127: Functional requirements for
over/under voltage protection (IEC 60255-127)
EN 61000-4-30, Electromagnetic compatibility (EMC) — Part 4-30: Testing and measurement
techniques — Power quality measurement methods (IEC 61000-4-30)
EN 61869-3, Instrument transformers — Part 3: Additional requirements for inductive voltage
transformers (IEC 61869-3)
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
Note: Terms and definitions are selected to achieve consistency with IEV (cf. www.electropedia.org)
and CENELEC terminology, recognizing that terms in COMMISSION REGULATION (EU) 2016/631
may deviate.
3.1 General
3.1.1
distribution network
AC electrical network, including closed distribution networks, for the distribution of electrical power from
and to third parties connected to it, to and from a transmission or another distribution network, for which
a DSO is responsible
Note 1 to entry: A distribution network does not include the producer’s network
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3.1.2
closed distribution network
system which distributes electricity within an industrial, commercial or shared services site, that is
geographically confined, and does not supply households customers (without excluding the option of a
small number of households served by the system that have an employment or similar associations with
the owner of the system)
Note 1 to entry: A closed distribution network will either be used to integrate the production processes of the
network users for specific or technical reasons or distribute electricity primarily to the operator of the closed
distribution network or his related undertakings
[SOURCE: Directive 2009/72/EC, article 28, modified]
3.1.3
distribution system operator
DSO
natural or legal person responsible for the distribution of electrical power to final customers and for
operating, ensuring the maintenance of and, if necessary, developing the distribution network in a given
area
Note 1 to entry: As this document is applicable to distribution grids, DSO is used for relevant system operator
according to article 2 (13) of COMMISSION REGULATION 2016/631.
Note 2 to entry: In some countries, the distribution network operator (DNO) fulfils the role of the DSO.
3.1.4
transmission system operator
natural or legal person responsible for operating, ensuring the maintenance of and, if necessary,
developing the transmission system in a given area and, where applicable, its interconnections with
other power systems, and for ensuring the long-term ability of the power system to meet reasonable
demands for the transmission of electricity
3.1.5
...
SLOVENSKI STANDARD
oSIST prEN 50549-2:2017
01-julij-2017
1DGRPHãþD
SIST-TS CLC/TS 50549-2:2015
Zahteve za vzporedno vezavo generatorskih postrojev z javnim razdelilnim
omrežjem - 2. del: Vezava s srednjenapetostnim razdelilnim omrežjem
Requirements for generating plants to be connected in parallel with distribution networks
- Part 2: Connection to a MV distribution network
Ta slovenski standard je istoveten z: prEN 50549-2
ICS:
29.160.20 Generatorji Generators
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
oSIST prEN 50549-2:2017 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 50549-2:2017
EUROPEAN STANDARD DRAFT
prEN 50549-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2017
ICS 29.160.20 Will supersede CLC/TS 50549-2:2015
English Version
Requirements for generating plants to be connected in parallel
with distribution networks - Part 2: Connection to a MV
distribution network
To be completed To be completed
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2017-08-18.
It has been drawn up by CLC/TC 8X.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CENELEC 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 63321 Ref. No. prEN 50549-2 E
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1 Contents Page
2
3 European foreword . 4
4 1 Scope . 5
5 2 Normative references . 6
6 3 Terms and definitions . 6
7 3.1 General . 6
8 3.2 Plant, module and unit . 7
9 3.3 Power . 9
10 3.4 Voltage . 9
11 3.5 Circuit theory . 10
12 3.6 Protection . 12
13 3.7 Control . 16
14 4 Requirements on generating plants . 18
15 4.1 General . 18
16 4.2 Connection scheme . 18
17 4.3 Choice of switchgear . 19
18 4.4 Normal operating range . 19
19 4.5 Immunity to disturbances . 21
20 4.6 Active response to frequency deviation . 24
21 4.7 Power response to voltage variations and voltage changes . 29
22 4.8 EMC and power quality . 36
23 4.9 Interface protection . 37
24 4.10 Connection and starting to generate electrical power. 43
25 4.11 Ceasing and reduction of active power on set point . 44
26 4.12 Remote information exchange . 44
27 Annex A (informative) Interconnection requirements . 45
28 A.1 General . 45
29 A.2 Network integration . 45
30 A.3 Clusters of single-phase generating units . 46
31 Annex B (informative) Remote information exchange . 47
32 Annex C (informative) Parameter Table . 53
33 Annex D (informative) List of national requirements applicable for Generating plants . 56
34 Annex E (informative) Loss of Mains and overall power system security . 57
35 Annex F (informative) Examples of protection strategies . 58
36 F.1 Introduction . 58
37 F.1.1 General . 58
38 F.1.2 Generalities . 58
39 F.1.3 Detection of unwanted islands . 58
40 F.1.4 Problems with uncontrolled islanding in MV networks . 59
41 F.2 Example strategy 1 . 60
42 F.3 Example strategy 2 . 63
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43 Annex G (normative) Abbreviations . 65
44 Annex H (informative) Relationship between this European standard and the
45 COMISSION REGULATION (EU)2016/631 . 66
46 Bibliography . 67
47
48
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49 European foreword
50 This document (prEN 50549-2:2017) has been prepared by CLC/TC 8X “System aspects of electrical
51 energy supply”.
52 This document is currently submitted to the Enquiry.
53 The following dates are proposed:
• latest date by which the existence of (doa) dor + 6 months
this document has to be announced
at national level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication
of an identical national standard or by
endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to (to be confirmed or
be withdrawn modified when voting)
54 This document will supersede CLC/TS 50549-2:2015.
55 This document has been prepared under a mandate given to CENELEC by the European Commission
56 and the European Free Trade Association.
57 This European Standard relates to both European Network Codes and current technical market
58 needs. Its purpose is to give detailed description of functions to be implemented in products.
59 This European Standard is also intended to serve as a technical reference for the definition of national
60 requirements where European Network Codes requirements allow flexible implementation. The
61 specified requirements are solely technical requirements; economic issues regarding, e.g. the bearing
62 of cost are not in the scope of this document.
63 CLC/TC 8X plans future standardization work in order to ensure the compatibility of this European
64 Standard (EN) with the evolution of the legal framework.
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65 1 Scope
66 This European Standard specifies the technical requirements for the protection functions and the
67 operational capabilities for generating plants, intended to operate in parallel with MV distribution
68 networks.
69 For practical reasons, this European Standard refers to the relevant distribution system operator
70 where settings have to be defined and/or provided, even when these settings are to be defined and/or
71 provided by another actor e.g. TSO, Member state, regulatory authorities, according to national and
72 European legal framework.
73 NOTE 1 This includes European network codes and their national implementation, as well as additional national
74 regulations.
75 NOTE 2 Additional national requirements especially for the connection to the distribution network and the
76 operation of the generating plant may apply.
77 The requirements of this European Standard apply to all generating plants, generating modules,
78 electrical machinery and electronic equipment, irrespective of the kind of primary energy source and
79 irrespective of the presence of loads in the producer’s network that meet all of the following conditions:
80 • converting any primary energy source into AC electricity;
81 • connected to a MV distribution network
82 • generating modules capacity of Type B or smaller according to COMMISSION REGULATION
83 (EU) 2016/631while considering national implementation for the decision regarding power limits
84 between A and B types and B and C types;
85 • intended to operate in parallel with a distribution network.
86 If generating modules of different type are combined in one plant, different requirements apply for the
87 different modules based on the type of each module.
88 NOTE 3 Generating plants connected to a LV distribution network fall into the scope of EN 50549–1.
89 Unless specified otherwise by the DSO, a generating with a maximum apparent power up to 100 kVA
90 can, as alternative to the requirements of this European Standard, comply with EN 50549-1. A
91 different threshold may be defined by the DSO.
92 This European Standard defines connection requirements for generating plants to be connected in
93 parallel with distribution networks.
94 This European Standard recognizes the existence of National Standards, Network Codes, and specific
95 technical requirements of the DSOs and these should be complied with.
96 Excluded from the scope are:
97 • the selection and evaluation of the point of connection;
98 • power system impact assessment;
99 • connection assessment;
100 • island operation of generating plants, both intentional and unintentional, where no part of the
101 distribution network is involved;
102 • four-quadrant rectifier of drives feeding breaking energy back into the distribution network for
103 limited duration with no internal source of primary energy;
104 • Uninterruptible power supply with duration of parallel operation limited to 100ms
105 NOTE 4 Parallel operation due to maintenance of uninterruptible power supply units is not considered.
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106 • requirements for the safety of personnel as they are already adequately covered by existing
107 European Standards.
108 2 Normative references
109 The following documents, in whole or in part, are normatively referenced in this document and are
110 indispensable for its application. For dated references, only the edition cited applies. For undated
111 references, the latest edition of the referenced document (including any amendments) applies.
112 EN 60044-2, Instrument transformers — Part 2: Inductive voltage transformers (IEC 60044-2)
113 EN 60044-7, Instrument transformers — Part 7: Electronic voltage transformers (IEC 60044-7)
114 EN 60255-127, Measuring relays and protection equipment — Part 127: Functional requirements for
115 over/under voltage protection (IEC 60255-127)
116 EN 61000-4-30, Electromagnetic compatibility (EMC) — Part 4-30: Testing and measurement
117 techniques — Power quality measurement methods (IEC 61000-4-30)
118 EN 61869-3, Instrument transformers — Part 3: Additional requirements for inductive voltage
119 transformers (IEC 61869-3)
120 3 Terms and definitions
121 For the purposes of this document, the following terms and definitions apply.
122 3.1 General
123 3.1.1
124 distribution network
125 electrical network, including closed distribution networks, for the distribution of electrical power from
126 and to third parties connected to it, to and from a transmission or another distribution network, for
127 which a DSO is responsible
128 3.1.2
129 closed distribution network
130 a system which distributes electricity within a geographically confined, industrial, commercial or shared
131 services site and does not (without prejudice to a small number of households located within the area
132 served by the system and with employment or similar associations with the owner of the system)
133 supply households customers. This Closed Distribution Network will either have its operations or the
134 production process of the users of the system integrated for specific or technical reasons or distribute
135 electricity primarily to the owner or operator of the Closed Distribution Network or their related
136 undertakings
137 3.1.3
138 distribution system operator - DSO
139 natural or legal person responsible for the distribution of electrical power to the public and for
140 operating, ensuring the maintenance of and, if necessary, developing the distribution network in a
141 given area
142 Note 1 to entry: in this document applicable to distribution grids DSO is used for relevant system operator
143 according Article 2 (13) of COMISSION REGULATION 2016/631
144 Note 2 to entry: In some countries, the distribution network operator (DNO) fulfils the role of the DSO.
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145 3.1.4
146 transmission system operator - TSO
147 natural or legal person responsible for operating, ensuring the maintenance of and, if necessary,
148 developing the transmission system in a given area and, where applicable, its interconnections with
149 other power systems, and for ensuring the long-term ability of the power system to meet reasonable
150 demands for the transmission of electricity
151 3.1.5
152 medium voltage (MV) distribution network
153 electric distribution network with a voltage whose nominal r.m.s. value is 1 kV < Un ≤ 36 kV
154 Note 1 to entry: Because of existing network structures, the upper boundary of MV can be different in some
155 countries.
156 3.1.6
157 power system stability
158 the capability of a power system to regain a steady state, characterized by the synchronous operation
159 of the generating plants after a disturbance
160 [SOURCE: IEV 603-03-01]
161 3.1.7
162 producer
163 natural or legal person who already has or is planning to connect an electricity generating plant to a
164 distribution network
165 3.1.8
166 producer’s network
167 electrical installations downstream from the point of connection owned/operated by the producer for
168 internal distribution of electricity
169 3.1.9
170 downstream
171 direction in which the active power would flow if no generating units, connected to the distribution
172 network, were running
173 3.1.10
174 point of connection - POC
175 reference point on the electric power system where the user’s electrical facility is connected
176 Note 1 to entry: For the purpose of this standard, the electric power system is the distribution network.
177 [SOURCE: IEV 617-04-01 modified]
178 3.1.11
179 operating in parallel with the distribution network
180 situation where the generating plant is connected to a distribution network and operating
181 3.1.12
182 temporary operation in parallel with the distribution network
183 conditions in which the generating plant is connected to a distribution network, during defined short
184 periods, to maintain the continuity of the supply voltage and to facilitate testing
185 3.2 Plant, module and unit
186 3.2.1
187 generating module
188 either a generating unit of synchronous generating technology or the sum of all generating units of
189 non-synchronous generating technology connected to a common point of connection including all
190 elements needed to feed electric power to the distribution grid
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191
192 Figure 1 — Generating module at a common POC
193 3.2.2
194 generating plant
195 sum of generating modules connected at one point of connection, including auxiliaries and all
196 connection equipment
197 Note 1 to entry: This definition is intended to be used for verification of compliance to the technical requirements
198 of this standard. It may be different to the legal definition of a plant.
199 3.2.3
200 generating unit
201 smallest set of installations which can generate electrical energy running independently and which can
202 feed this energy into a distribution network
203 Note 1 to entry: For example, a combined cycle gas turbine (CCGT) or an organic rankine cycle (ORC) after a
204 combustion engine is considered as a single generating unit.
205 Note 2 to entry: If a generating unit is a combination of technologies leading to different requirements, this has to
206 be settled case by case.
207 Note 3 to entry: A storage device operating in electricity generation mode and AC connected to the distribution
208 network is considered to be a generating unit.
209 3.2.4
210 synchronously coupled generating technology
211 technology where a generating unit is based on a synchronous machine which is directly coupled
212 3.2.5
213 non-synchronous generating technology
214 technology where a generating unit is connected non-synchronously to a distribution grid
215 Note 1 to entry: Examples are: induction machines and converter based technologies.
216 3.2.6
217 cogeneration -combined heat and power (CHP)
218 combined generation of electricity and heat by an energy conversion system and the concurrent use of
219 the electric and thermal energy from the conversion system
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220 3.3 Power
221 3.3.1
222 design active power - P
D
223 maximum AC active power output at an active factor of 0,9 or the active factor specified by the DSO
224 for a certain generating plant or generating technology
225 3.3.2
226 maximum active power - P
max
227 maximum continuous active power which a power-generating plant can produce, less any demand
228 associated solely with facilitating the operation of that power-generating plant and not fed into the
229 network as specified in the connection agreement or as agreed between the DSO and the power-
230 generating facility owner
231 Note 1 to entry: This maximum power is defined by a measurement with 10 min averaging.
232 3.3.3
233 rated current
234 maximum continuous AC output current which a generating unit or generating plant is designed to
235 achieve under normal operating conditions
236 [SOURCE: IEV 415-04-03, modified]
237 3.3.4
238 maximum apparent power - S
max
239 maximum AC apparent power output that the generating unit or the sum of all the generating units in a
240 generating plant is designed to achieve under normal operating conditions
241 Note 1 to entry: This maximum power is defined by a measurement with 10 min averaging.
242 3.3.5
243 momentary active power - P
M
244 actual AC active power output at a certain instant
245 3.3.6
246 primary energy source
247 non-electric energy source supplying an electric generating unit
248 Note 1 to entry: Examples of primary energy sources include natural gas, wind and solar energy. These sources
249 can be utilized, e.g. by gas turbines, wind turbines and photovoltaic cells.
250 3.3.7
251 available active power - P
A
252 maximum AC active power available from the prime mover subject to the availability and magnitude of
253 the primary energy source at the relevant time
254 Note 1 to entry: The maximum active power considers all constraints regarding e.g. the primary energy source or
255 the availability of a heat sink for CHP.
256 3.4 Voltage
257 3.4.1
258 nominal voltage - U
n
259 voltage by which a supply network is designated or identified and to which certain operating
260 characteristics are referred
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261 3.4.2
262 nominal frequency - f
n
263 frequency used to designate and identify equipment or a power system
264 Note 1 to entry: For the purpose of this standard, the nominal frequency f is 50 Hz.
n
265 [SOURCE: IEV 151-16-09, modified]
266 3.4.3
267 declared supply voltage - U
C
268 supply voltage UC agreed by the power system operator and the network user
269 Note 1 to entry: Generally declared supply voltage UC is the nominal voltage UN but it may be different according
270 to the agreement between the DSO and the network user.
271 [SOURCE: EN 50160]
272 3.4.4
273 reference voltage
274 value specified as the base on which residual voltage, thresholds and other values are expressed in
275 per unit or percentage terms
276 Note 1 to entry: For the purpose of this standard, the reference voltage is the nominal voltage or the declared
277 voltage of the distribution network.
278 [SOURCE: EN 50160:2010, 3.18, modified]
279 3.4.5
280 voltage change
281 variation of the r.m.s. value of a voltage between two consecutive levels sustained for definite but
282 unspecified durations
283 [SOURCE: IEV 161-08-01, modified]
284 3.4.6
285 voltage variation
286 increase or decrease of r.m.s. voltage normally due to load variations in load and/or generation
287 [SOURCE: EN 50160:2010, 3.34, modified]
288 3.5 Circuit theory
289 3.5.1
290 active factor
291 for a two-terminal element or a two-terminal circuit under sinusoidal conditions, ratio of the active
292 power to the apparent power
293 Note 1 to entry: In a three phase system, this is referring to the positive sequence component of the fundamental.
294 Note 2 to entry: The active factor is equal to the cosine of the displacement angle.
295 [SOURCE: IEV 131-11-49, modified]
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296 3.5.2
297 displacement angle - φ
298 under sinusoidal conditions, phase difference between the voltage applied to a linear two-terminal
299 element or two-terminal circuit and the electric current in the element or circuit
300 Note 1 to entry: In a three phase system, this is referring to the positive sequence component of the fundamental.
301 Note 2 to entry: The cosine of the displacement angle is the active factor.
302 [SOURCE IEV 131-11-48 modified]
303 3.5.3
304 power factor
305 under periodic conditions, ratio of the absolute value of the active power P to the apparent
306 power S:
| |
𝑃𝑃
307 𝜆𝜆 =
𝑆𝑆
308 Note 1 to entry: Under sinusoidal conditions, the power factor is the absolute value of the active factor.
309 [SOURCE: IEV 131-11-46]
310 3.5.4
311 fundamental components of a three-phase system
312 3.5.4.1
313 phasor
314 representation of a sinusoidal integral quantity by a complex quantity whose argument is equal to the
315 initial phase and whose modulus is equal to the root-mean-square value
316 Note 1 to entry: For a quantity a(t) = A √2 cos(ωt +Ө0) the phasor is A exp Jө0.
317 Note 2 to entry: The similar representation with the modulus equal to the amplitude is called “amplitude phasor”.
318 Note 3 to entry: A phasor can also be represented graphically.
319 [SOURCE: IEV 131-11-26, modified]
320 3.5.4.2
321 positive sequence component of the fundamental
322 for a three-phase system with phases L1, L2 and L3, the symmetrical sinusoidal three-phase set of
323 voltages or currents having frequency equal to the fundamental frequency and which is defined by the
324 following complex mathematical expression:
1
2
X = (X + aX + a X )
1 L1 L2 L3
3
325
j2π/3
326 where a = e is the 120 degree operator, and XL1, XL2 and XL3 are the complex expressions of the
327 fundamental frequency phase quantities concerned, that is, current or voltage phasors
328 Note 1 to entry: In a balanced harmonic-free system, only positive sequence component of the fundamental
jθ j(θ+4 /3) j(θ+2 /3)
329 exists. For example, if phase voltage phasors are symmetrical U = Ue , U = Ue π and U = Ue π
L1 L2 L3
jθ j2 /3 j(θ+4 /3) j4 /3 j(θ+2 /3) jθ jθ jθ jθ
330 then U = (Ue + e π Ue π + e π Ue π )/3 = (Ue + Ue + Ue )/3 = Ue
1
331 [SOURCE: IEV 448-11-27]
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332 3.5.4.3
333 negative sequence component of the fundamental
334 for a three-phase system with phases L1, L2 and L3, the symmetrical sinusoidal three-phase set of
335 voltages or currents having frequency equal to the fundamental frequency and which is defined by the
336 following complex mathematical expression:
1
2
X = (X + a X + aX )
2 L1 L2 L3
3
337
j2π/3
338 where a = e is the 120 degree operator, and XL1, XL2 and XL3 are the complex expressions of the
339 fundamental frequency phase quantities concerned, that is, current or voltage phasors
340 Note 1 to entry: Negative sequence voltage or current components may be significant only when the voltages or
jθ
341 currents, respectively, are unbalanced. For example, if phase voltage phasors are symmetrical UL1 = Ue ,
j(θ+4 /3) j(θ+2 /3) jθ j4 /3 j(θ+4 /3) j2 /3
342 UL2 = Ue π and UL3 = Ue π then the negative sequence component U2 = (Ue + e π Ue π + e π
j(θ+2 /3) jθ j2 /3 j4 /3
343 Ue π )/3 = Ue (1 + e π + e π )/3 = 0.
344 [SOURCE: IEV 448-11-28]
345 3.5.4.4
346 zero sequence component of the fundamental
347 for a three-phase system with phases L1, L2 and L3, the in-phase sinusoidal voltage or current
348 component having the fundamental frequency and equal amplitude in each of the phases and which is
349 defined by the following complex mathematical expression:
1
( )
X = X +X +X
0 L1 L2 L3
3
350
351 where XL1, XL2 and XL3 are the complex expressions of the fundamental frequency phase quantities
352 concerned, that is, current or voltage phasors
353 [SOURCE: IEV 448-11-29]
354 3.6 Protection
355 3.6.1
356 protection system
357 an arrangement of one or more protection equipments, and other devices intended to perform one or
358 more specified protection functions
359 Note 1 to entry: A protection system includes one or more protection equipments, instrument transformer(s),
360 wiring, tripping circuit(s), auxiliary supply(s) and, where provided, communication system(s). Depending upon the
361 principle(s) of the protection system, it may include one end or all ends of the protected section and, possibly,
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