CLC/TS 50549-2:2015

Requirements for generating plants to be connected in parallel with distribution networks - Part 2: Connection to a MV distribution network

The purpose of this Technical Specification is to provide technical guidance on the requirements for generating plants which can be operated in parallel with a distribution network. For practical reasons, this Technical Specification refers to the distribution system operator in case settings have to be defined and/or provided, even when these settings are to be defined and/or provided by another actor according to national and European legal framework. NOTE 1 This includes European network codes and their national implementation, as well as further national regulations. NOTE 2 Further national requirements especially for the connection to the distribution network and the operation of the generating plant can apply. The requirements of this Technical Specification apply to all generating plants, electrical machinery and electronic equipment, irrespective of the kind of primary energy source and irrespective of the presence of loads in the producer’s network that meet all of the following conditions: - converting any primary energy source into AC electricity; - connected to a MV distribution network; - intended to operate in parallel with this distribution network under normal network operating conditions. NOTE 3 Generating plants connected to a LV distribution network fall into the scope of EN 50438 (up to 16 A) and CLC/TS 50549-1 (above 16 A). Unless stated differently by the DSO, a generating plant with a maximum apparent power up to 100 kVA can, as alternative to the requirements of this Technical Specification, comply with CLC/TS 50549-1. A different threshold may be defined by the DSO. This Technical Specification defines connection requirements. This Technical Specification recognizes the existence of National Standards, Network Codes, and specific technical requirements of the DSOs. These should be complied with. Excluded from the scope are: - the selection and evaluation of the point of connection; - power system impact assessment; - connection assessment; - island operation of generating plants, both intentional and unintentional, where no part of the distribution network is involved; - active front ends of drives feeding energy back into the distribution network for short duration; - requirements for the safety of personnel as they are already adequately covered by existing European Standards.

Anforderungen für zum Parallelbetrieb mit einem Verteilnetz vorgesehene Erzeugungsanlagen – Teil 2: Anschluss an das Mittelspannungsverteilnetz

Diese Technische Spezifikation legt die technischen Anforderungen für den Anschluss von Erzeugungsanlagen fest, die parallel mit einem öffentlichen Verteilungsnetz betrieben werden können. Diese Technische Spezifikation soll als Referenz in einer Anschlussgenehmigung herangezogen werden, die zwischen einem VNB und einem Erzeuger getroffen wird. Die Anforderungen dieser Technischen Spezifikation beschränken sich auf den elektrischen Teil der Anlage, unabhängig von der verwendeten Primärenergiequelle. Diese Technische Spezifikation gilt für alle dreiphasigen Erzeugungseinheiten, welche die folgenden Bedingungen – entweder als Einzelanlage oder als Gruppe von mehreren Anlagen mit einem gemeinsamen Anschlusspunkt – erfüllen: • Umwandlung einer beliebigen Primärenergie in Wechselstrom; • Bemessungsströme größer 16 A pro Phase und Anschluss an ein Niederspannungsnetz; • Anlagen, die unter normalen Netzbetriebsbedingungen ständig parallel mit einem öffentlichen Ver-teilungsnetz betrieben werden sollen; Diese Technische Spezifikation legt die Anschlussbedingungen und ein Verfahren für die Konformitätsprüfung fest. Der Inselnetzbetrieb von Erzeugungsanlagen – beabsichtigt oder unbeabsichtigt – bei dem kein Teil des öffentlichen Verteilungsnetzes betroffen ist, liegt nicht im Anwendungsbereich dieser Technischen Spezifikation. Die Personensicherheit liegt nicht im Anwendungsbereich dieser Technischen Spezifikation. Diese Norm anerkennt die Existenz von nationalen Normen und Grid Codes: diese müssen eingehalten werden. Nur wenn keine nationalen Normen und Grid Codes vorhanden sind, sollen die Anforderungen dieser Technischen Spezifikation zur Anwendung kommen.

Prescriptions relatives au raccordement de générateurs de plus de 16A par phase - Partie 2: Connexion au réseau de distribution MT

L'objet de la présente Spécification Technique est de fournir des instructions techniques pour le raccordement des centrales de production pouvant fonctionner en parallèle avec un réseau de distribution public. La présente Spécification Technique est destinée à être utilisée comme référence technique dans les contrats de raccordement entre les GRD et les producteurs d'électricité. Les exigences contenues dans la présente Spécification Technique s'appliquent uniquement aux machines et au matériel, quelle que soit la source d'énergie primaire. La présente Spécification Technique s'applique à toutes les unités de production triphasées qui satisfont à toutes les conditions qui suivent en tant qu'unité de production individuelle ou en tant que groupe d'unités de production ayant un point de raccordement commun: • convertit toute source d'énergie primaire en électricité en courant alternatif; • est raccordé(e) au réseau MT; • est destiné(e) à fonctionner en parallèle avec un réseau de distribution public dans des conditions de fonctionnement normales. La présente Spécification Technique définit les exigences applicables aux interconnexions ainsi qu'une procédure d'essai de conformité. Le fonctionnement en îlotage de centrales de production, qu'il soit intentionnel ou non, dans lequel aucune partie du système de distribution public n'est impliquée, est en dehors du domaine d'application de la présente Spécification Technique. La sécurité du personnel est en dehors du domaine d'application de la présente Spécification Technique. La présente Spécification Technique reconnaît l'existence de normes et de codes nationaux applicables aux réseaux: ceux-ci doivent être respectés. Il convient que les exigences de la présente Spécification Technique s'appliquent uniquement en l'absence de ces normes et codes nationaux.

Zahteve za priklop generatorjev za toke nad 16 A na fazo - 2. del: Priklop na srednjenapetostni distribucijski sistem

Namen te tehnične specifikacije je zagotoviti tehnična navodila za povezavo generatorjev, ki jih je mogoče upravljati hkrati z javnim razdelilnim omrežjem.
Ta tehnična specifikacija naj se ne bi uporabljala kot tehnična referenca v dogovorih o priključku med upravljavci razdelilnih omrežij in proizvajalci električne energije.
Zahteve iz te tehnične specifikacije se uporabljajo le za električne stroje in opremo, ne glede na vrsto vira primarne energije.
Ta tehnična specifikacija se uporablja za vse trifazne generatorske enote, ki izpolnjujejo vse naslednje pogoje kot individualna generatorska enota ali kot skupina generatorskih enot s skupno točko priključitve:
• pretvarjanje katerega koli vira primarne energije v izmenični tok;
• povezava v srednjenapetostno omrežje;
• namenjeni so za uporabo skupaj z javnim razdelilnim omrežjem v običajnih pogojih delovanja omrežja.
Ta tehnična specifikacija določa zahteve glede medsebojne povezave in postopek izvajanja preskusov skladnosti.
Ločeno delovanje generatorskih obratov, namerno in nenamerno, kadar ni vključen noben del javnega razdelilnega omrežja, ni zajeto v tej tehnični specifikaciji.
Varnost osebja ni zajeta v tej tehnični specifikaciji.
Ta tehnična specifikacija priznava obstoj nacionalnih standardov in omrežnih kodeksov; te standarde in kodekse je treba upoštevati. Zahteve iz te tehnične specifikacije naj bi se uporabljale le, če takih nacionalnih standardov in kodeksov ni.

General Information

• Status: Withdrawn
• Publication Date: 15-Jan-2015
• ICS: 29.160.20 - Generators
• Technical Committee: CLC/TC 8X - System aspects of electrical energy supply
• Drafting Committee: CLC/TC 8X - System aspects of electrical energy supply
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 01-Feb-2022
• Completion Date: 01-Feb-2022
• Mandate: M/490 - Standardisation mandate to the European Standardisation Organisations (ESOs) to support European Smart Grid deployment
• Ref Project: SIST-TS CLC/TS 50549-2:2015 - Requirements for the connection of generators above 16 A per phase - Part 2: Connection to the MV distribution system

Relations

• Replaced By: EN 50549-2:2019 - 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
• Effective Date: 23-Aug-2016

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2015
Zahteve za priklop generatorjev za toke nad 16 A na fazo - 2. del: Priklop na
srednjenapetostni distribucijski sistem
Requirements for the connection of generators above 16 A per phase - Part 2:
Connection to the MV distribution system
Prescriptions relatives au raccordement de générateurs de plus de 16A par phase -
Partie 2: Connexion au réseau de distribution MT
Ta slovenski standard je istoveten z: CLC/TS 50549-2:2015
ICS:
29.160.20 Generatorji Generators
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION CLC/TS 50549-2

SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
January 2015
ICS 29.160.20
English Version
Requirements for generating plants to be connected in parallel
with distribution networks - Part 2: Connection to a MV
distribution network
Prescriptions relatives au raccordement de générateurs de Anforderungen für den Anschluss von
plus de 16A par phase - Partie 2: Connexion au réseau de Stromerzeugungsanlagen über 16 A je Phase - Teil 2:
distribution MT Anschluss an das Mittelspannungsverteilungsnetz
This Technical Specification was approved by CENELEC on 2014-09-15.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to make the TS available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force.

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, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TS 50549-2:2015 E

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .5
4 Requirements on generating plants . 15
4.1 General . 15
4.2 Connection scheme . 16
4.3 Choice of switchgear . 16
4.4 Normal operating range . 16
4.5 Immunity to disturbances . 18
4.6 Active response to frequency deviation . 21
4.7 Power response to voltage variations and voltage changes . 23
4.8 EMC and power quality . 29
4.9 Interface protection . 30
4.10 Connection and starting to generate electrical power . 35
4.11 Active power reduction on set point . 36
4.12 Remote information exchange . 37
5 Conformance test procedure . 37
Annex A (informative)  Interconnection requirements . 38
Annex B (informative) Remote information exchange . 40
Annex C (informative) Frequency stabilizing services . 46
C.1 General . 46
C.2 Frequency sensitive mode . 46
C.3 Power system stabilization . 47
C.4 Synthetic inertia . 47
Annex D (informative) Loss of Mains and overall power system security . 48
Annex E (informative) Examples of protection strategies . 49
E.1 Introduction . 49
E.1.1 General . 49
E.2 Example strategy 1 . 50
E.3 Example strategy 2 . 54
Annex F (normative) Abbreviations . 56
Bibliography . 57

- 3 - CLC/TS 50549-2:2015
Foreword
This document (CLC/TS 50549-2:2015) has been prepared by CLC/TC 8X "System aspects of
electrical energy supply".
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This Technical Specification relates to both future European Network Codes and current technical
market needs. Its purpose is to give detailed description of functions to be implemented in products.
This Technical Specification is also intended to serve as a technical reference for the definition of
national requirements where European Network Codes requirements allow flexible implementation.
The stated 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 Technical
Specification with the evolution of the legal framework.

1 Scope
The purpose of this Technical Specification is to provide technical guidance on the requirements for
generating plants which can be operated in parallel with a distribution network.
For practical reasons, this Technical Specification refers to the distribution system operator in case
settings have to be defined and/or provided, even when these settings are to be defined and/or
provided by another actor according to national and European legal framework.
NOTE 1 This includes European network codes and their national implementation, as well as further national
regulations.
NOTE 2 Further national requirements especially for the connection to the distribution network and the
operation of the generating plant can apply.
The requirements of this Technical Specification apply to all generating plants, electrical machinery
and electronic equipment, irrespective of the kind of primary energy source and irrespective of the
presence of loads in the producer’s network that meet all of the following conditions:
– converting any primary energy source into AC electricity;
– connected to a MV distribution network;
– intended to operate in parallel with this distribution network under normal network operating
conditions.
NOTE 3 Generating plants connected to a LV distribution network fall into the scope of EN 50438 (up to 16 A)
and CLC/TS 50549-1 (above 16 A).
Unless stated differently by the DSO, a generating plant with a maximum apparent power up to 100
kVA can, as alternative to the requirements of this Technical Specification, comply with
CLC/TS 50549-1. A different threshold may be defined by the DSO.
This Technical Specification defines connection requirements.
This Technical Specification recognizes the existence of National Standards, Network Codes, and
specific technical requirements of the DSOs. These should be complied with.
Excluded from the scope are:
– the selection and evaluation of the point of connection;
– power system impact assessment;
– connection assessment;
– island operation of generating plants, both intentional and unintentional, where no part of the
distribution network is involved;
– active front ends of drives feeding energy back into the distribution network for short duration;
– requirements for the safety of personnel as they are already adequately covered by existing
European Standards.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
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)

- 5 - CLC/TS 50549-2:2015
 Part 127: Functional requirements for
EN 60255-127, Measuring relays and protection equipment
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)
IEC 60050, International Electrotechnical Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050 and the following
apply.
3.1
active factor
for a two-terminal element or a two-terminal circuit under sinusoidal conditions, ratio of the active
power to the apparent power
Note 1 to entry:  In a three phase system this is referring to the positive sequence component of the fundamental.
Note 2 to entry:  The active factor is equal to the cosine of the displacement angle.
[SOURCE: IEV 131-11-49, modified]
3.2
available active power
P
A
maximum AC active power available from the prime mover subject to the availability and magnitude of
the primary energy source at the relevant time
Note 1 to entry:  The maximum active power considers all constraints regarding e.g. the primary energy source or
the availability of a heat sink for CHP.
3.3
basic insulation
insulation of hazardous-live-parts which provides basic protection
Note 1 to entry: This concept does not apply to insulation used exclusively for functional purposes.
[SOURCE: IEV 195-06-06]
3.4
basic protection
protection against electric shock under fault-free conditions
[SOURCE: IEV 195-06-01]
3.5
cogeneration
combined heat and power (CHP)
combined generation of electricity and heat by an energy conversion system and the concurrent use of
the electric and thermal energy from the conversion system
3.6
converter connected generating technology
technology where a generating unit is connected to a distribution grid through a converter including
doubly fed induction machine based technology (DFIG)

3.7
declared supply voltage
U
c
supply voltage U agreed by the power system operator and the network user
c
Note 1 to entry:  Generally declared supply voltage U is the nominal voltage U but it may be different according
c n
to the agreement between the power system operator and the network user.
[SOURCE: EN 50160]
3.8
design active power
P
D
maximum AC active power output at an active factor of 0,9 or the active factor specified by the DSO
for a certain generating plant or generating technology
3.9
directly coupled generating technology
technology where a generating unit is connected to a distribution grid without any converter
Note 1 to entry:  Soft starters are not considered as converter in this definition.
3.10
disconnection
separation of the active parts of the main circuit of the generating plant or unit from the network with
mechanical contacts providing at least the equivalent of basic insulation
Note 1 to entry:  Passive components like filters, auxiliary power supply to the generating unit and sense lines
can remain connected.
...