EN 60909-3:2010

Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through earth

IEC 60909-3:2009 specifies procedures for calculation of the prospective short-circuit currents with an unbalanced short circuit in high-voltage three-phase a.c. systems operating at nominal frequency 50 Hz or 60 Hz, i. e.: - currents during two separate simultaneous line-to-earth short circuits in isolated neutral or resonant earthed neutral systems; - partial short-circuit currents flowing through earth in case of single line-to-earth short circuit in solidly earthed or low-impedance earthed neutral systems. The currents calculated by these procedures are used when determining induced voltages or touch or step voltages and rise of earth potential at a station (power station or substation) and the towers of overhead lines. Procedures are given for the calculation of reduction factors of overhead lines with one or two earth wires. This edition constitutes a technical revision. The main changes with respect to the previous edition are: - New procedures are introduced for the calculation of reduction factors of the sheaths or shields and in addition the current distribution through earth and the sheaths or shields of three-core cables or of three single-core cables with metallic non-magnetic sheaths or shields earthed at both ends; - The information for the calculation of the reduction factor of overhead lines with earth wires are corrected and given in the new Clause 7; - A new Clause 8 is introduced for the calculation of current distribution and reduction factor of three-core cables with metallic sheath or shield earthed at both ends; - The new Annexes C and D provide examples for the calculation of reduction factors and current distribution in case of cables with metallic sheath and shield earthed at both ends. This publication is to be read in conjunction with IE C 60909-0:2001. NEW! IEC 60909-3:2009 is also available as IEC Standards+ 60909-3:2009 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

Kurzschlussströme in Drehstromnetzen - Teil 3: Ströme bei Doppelerdkurzschluss und Teilkurzschlussströme über Erde

Courants de court-circuit dans les réseaux triphasés à courant alternatif - Partie 3: Courants durant deux courts-circuits monophasés simultanés séparés à la terre et courants de court-circuit partiels s'écoulant à travers la terre

La CEI 60909-3:2009 spécifie les procédures applicables au calcul des valeurs présumées des courants de court-circuit lors d'un court-circuit déséquilibré dans les réseaux triphasés à haute tension à courant alternatif fonctionnant à une fréquence nominale de 50 Hz ou 60 Hz, c'est-à-dire: - les courants durant deux courts-circuits monophasés simultanés séparés à la terre dans les réseaux à neutre isolé ou mis à la terre par une bobine d'extinction; - les courants de court-circuit partiels s'écoulant à travers la terre, dans le cas d'un seul court-circuit monophasé à la terre dans les réseaux à neutre mis à la terre directement ou par une faible impédance. Les courants calculés suivant ces procédures sont utilisés pour la détermination des tensions induites ou des tensions de contact ou de pas, et de la montée du potentiel de terre d'un poste (groupe de production, poste), ainsi que les pylônes des lignes aériennes. Des procédures de calcul des facteurs de réduction des lignes aériennes avec un ou deux câbles de garde sont fournies. Cette édition constitue une révision technique. Les modifications principales par rapport à l'édition précédente sont les suivantes: - De nouvelles procédures sont fournies pour le calcul des facteurs de réduction des gaines ou des écrans, ainsi que pour la répartition du courant par la terre et les gaines ou les écrans des câbles à trois conducteurs ou de trois câbles monoconducteurs avec gaines ou écrans non magnétiques métalliques mis à la terre à chaque extrémité; - Les informations pour le calcul du facteur de réduction pour lignes aériennes avec câbles de garde sont corrigées et fournies en un nouvel Article 7; - Un nouvel Article 8 est introduit pour le calcul de la répartition du courant et du facteur de réduction des câbles avec gaine ou écran métallique, mis à la terre à chaque extrémité; - Les nouvelles Annexes C et D donnent des exemples pour le calcul des facteurs de réduction et de la répartition du courant dans le cas de câbles avec gaine ou écran métallique, mis à la terre à chaque extrémité. Cette publication doit être lue conjointement avec la CE I 60909-0:2001. NEW! La CEI 60909-3:2009 est également disponible sous forme de IEC Standards+ 60909-3:2009 qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.

Kratkostični toki v trofaznih izmeničnih sistemih - 3. del Toki med dvema ločenima sočasnima kratkima stikoma linijski-ozemljitveni vodnik in delnim kratkostičnim tokom, ki teče skozi ozemljitev (IEC 60909-3:2009))

Ta del IEC 60909 določa postopke za izračunavanje perspektivnih tokov kratkega stika z neuravnovešenim kratkim stikom v visoko-napetostnih trofaznih izmeničnih sistemih, ki delujejo pri nominalni frekvenci 50 Hz ali 60 Hz, to so.: a) toki med dvema ločenima sočasnima kratkima stikoma linijsko-ozemljitvenega vodnika v nevtralno izoliranih ali resonančnih ozemljenih nevtralnih sistemih; b) tokovi delnega kratkega stika, ki tečejo skozi zemljo v primeru enega linijsko-ozemljitvenega kratkega stika v nevtralnih sistemih, ki so trdno ozemljenih ali ozemljeni z nizko impedanco. Tokovi, izračunani s temi postopki, se uporabljajo, kadar se ugotavlja inducirana napetost ali dotik ali korak napetosti in dvig zemeljskega potenciala na centrali(električne centrale ali pod-centrale) in stolpih z nadzemnimi linijami. Podani so postopki za izračunavanje pretvornih faktorjev nadzemnih linij z eno ali dvema zemeljskima linijama. Ta standard ne zajema: a) tokov kratkega stika, ki so bili namenoma narejeni pod nadzorovanimi okoliščinami v centralah za preskušanje kratkih stikov ali b) tokov kratkega stika v električnih napeljavah na krovu ladij ali letal ali c) enojnih linijskih-ozemljitvenih napačnih tokov v izoliranih ali resonančno ozemljenih sistemih.  Cilj tega standarda je vzpostaviti praktične ter kratke in jedrnate postopke za izračunavanje linijskih-ozemljitvenih tokov kratkega stika med dvema ločenima sočasnima kratkima stikoma linijsko-ozemljitvenega vodnika in delnega kratkostičnega toka, ki teče skozi ozemljitev, ozemljenimi žicami nadzemnih linij in tulce ali ščite kablov, kar vodi do razumnih rezultatov z zadostno natančnostjo.  V ta namen so tokovi kratkega stika določeni z upoštevanjem enakovrednega vira napetosti na lokaciji kratkega stika, kjer so ostali viri napetosti nastavljenimi na nič.  Upornost ozemljenih omrežij v centralah ali koračnih uporih nadzemnih linijskih stolpov je zanemarljiva pri izračunavanju tokov kratkega stika na lokaciji kratkega stika. Ta standard je dodatek k IEC 60909-0. Splošne definicije, simboli in predpostavke izračunov se nanašajo na to objavo. V tem standardu so določene samo posebne postavke. Izračunavanje tokov kratkega stika, osnovano na nazivnih podatkih električne opreme in topoloških ureditev sistema, ima to prednost, da je izvedljivo tako za obstoječe sisteme kot za sisteme na stopnji načrtovanja.  Postopek je primeren da določanje ročnih metod ali digitalnih izračunov. To ne izključuje uporabe posebnih metod, na primer super-pozicijske metode, nastavljene za posebne okoliščine, če zagotavljajo vsaj enako natančnost. Kot je navedeno v IEC 60909-0, se tokovi kratkega stika in njihovi parametri lahko določijo s sistemskimi preskusi.

General Information

• Status: Published
• Publication Date: 11-Mar-2010
• Withdrawal Date: 28-Feb-2013
• ICS: 17.220.01 - Electricity. Magnetism. General aspects
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: CLC/SR 73 - Short-circuit currents
• Drafting Committee: IEC/TC 73 - IEC_TC_73
• Parallel Committee: IEC/TC 73 - IEC_TC_73
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 12-Mar-2010
• Completion Date: 12-Mar-2010
• Ref Project: SIST EN 60909-3:2010 - Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through earth (IEC 60909-3:2009)

Relations

• Replaces: EN 60909-3:2003 - Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through earth
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2010
1DGRPHãþD
SIST EN 60909-3:2004
.UDWNRVWLþQLWRNLYWURID]QLKL]PHQLþQLKVLVWHPLKGHO7RNLPHGGYHPDORþHQLPD
VRþDVQLPDNUDWNLPDVWLNRPDOLQLMVNLR]HPOMLWYHQLYRGQLNLQGHOQLPNUDWNRVWLþQLP
WRNRPNLWHþHVNR]LR]HPOMLWHY,(&
Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate
simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through
earth (IEC 60909-3:2009)
Kurzschlussströme in Drehstromnetzen - Teil 3: Ströme bei Doppelerdkurzschluss und
Teilkurzschlussströme über Erde (IEC 60909-3:2009)
Courants de court-circuit dans les réseaux triphasés à courant alternatif - Partie 3:
Courants durant deux court-circuits monophasés simultanés séparés à la terre et
courants de court-circuit partiels s'écoulant à travers la terre (CEI 60909-3:2009)
Ta slovenski standard je istoveten z: EN 60909-3:2010
ICS:
17.220.01 Elektrika. Magnetizem. Electricity. Magnetism.
Splošni vidiki General aspects
29.240.20 Daljnovodi Power transmission and
distribution lines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60909-3
NORME EUROPÉENNE
March 2010
EUROPÄISCHE NORM
ICS 17.220.01; 29.240.20 Supersedes EN 60909-3:2003

English version
Short-circuit currents in three-phase a.c systems -
Part 3: Currents during two separate simultaneous line-to-earth
short-circuits and partial short-circuit currents flowing through earth
(IEC 60909-3:2009)
Courants de court-circuit dans les réseaux Kurzschlussströme in Drehstromnetzen -
triphasés à courant alternatif - Teil 3: Ströme bei Doppelerdkurzschluss
Partie 3: Courants durant deux und Teilkurzschlussströme über Erde
courts-circuits monophasés simultanés (IEC 60909-3:2009)
séparés à la terre et courants
de court-circuit partiels s'écoulant
à travers la terre
(CEI 60909-3:2009)
This European Standard was approved by CENELEC on 2010-03-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60909-3:2010 E
Foreword
The text of document 73/148/FDIS, future edition 3 of IEC 60909-3, prepared by IEC TC 73, Short-circuit
currents, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 60909-3 on 2010-03-01.
This standard is to be used in conjunction with EN 60909-0:2001.
This European Standard supersedes EN 60909-3:2003.
The main changes with respect to EN 60909-3:2003 are listed below:
– New procedures are introduced for the calculation of reduction factors of the sheaths or shields and in
addition the current distribution through earth and the sheaths or shields of three-core cables or of
three single-core cables with metallic non-magnetic sheaths or shields earthed at both ends;
– The information for the calculation of the reduction factor of overhead lines with earth wires are
corrected and given in the new Clause 7;
– A new Clause 8 is introduced for the calculation of current distribution and reduction factor of three-
core cables with metallic sheath or shield earthed at both ends;
– The new Annexes C and D provide examples for the calculation of reduction factors and current
distribution in case of cables with metallic sheath and shield earthed at both ends.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2010-12-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-03-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60909-3:2009 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60909-3:2010
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60909-0 2001 Short-circuit currents in three-phase a.c. EN 60909-0 2001
systems -
Part 0: Calculation of currents

IEC/TR 60909-2 2008 Short-circuit currents in three-phase a.c. - -
systems -
Part 2: Data of electrical equipment for
short-circuit current calculations

IEC 60909-3 ®
Edition 3.0 2009-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Short-circuit currents in three-phase AC systems –
Part 3: Currents during two separate simultaneous line-to-earth short circuits
and partial short-circuit currents flowing through earth

Courants de court-circuit dans les réseaux triphasés à courant alternatif –
Partie 3: Courants durant deux courts-circuits monophasés simultanés séparés
à la terre et courants de court-circuit partiels s'écoulant à travers la terre

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XA
CODE PRIX
ICS 17.220.01; 29.240.20 ISBN 2-8318-1027-8
– 2 – 60909-3 © IEC:2009
CONTENTS
FOREWORD.5
1 Scope and object.7
2 Normative references .8
3 Terms and definitions .8
4 Symbols .10
5 Calculation of currents during two separate simultaneous line-to-earth short
circuits .12
5.1 Initial symmetrical short-circuit current .12
5.1.1 Determination of M and M .12
(1) (2)
5.1.2 Simple cases of two separate simultaneous line-to-earth short
circuits.13
5.2 Peak short-circuit current, symmetrical short circuit breaking current and
steady-state short-circuit current .13
5.3 Distribution of the currents during two separate simultaneous line-to-earth
short circuits.14
6 Calculation of partial short-circuit currents flowing through earth in case of an
unbalanced short circuit.14
6.1 General .14
6.2 Line-to-earth short circuit inside a station .15
6.3 Line-to-earth short circuit outside a station.16
6.4 Line-to-earth short circuit in the vicinity of a station.18
6.4.1 Earth potential U at the tower n outside station B .19
ETn
6.4.2 Earth potential of station B during a line-to earth short circuit at the
tower n .19
7 Reduction factor for overhead lines with earth wires .20
8 Calculation of current distribution and reduction factor in case of cables with
metallic sheath or shield earthed at both ends.21
8.1 Overview .21
8.2 Three-core cable .22
8.2.1 Line-to-earth short circuit in station B .22
8.2.2 Line-to-earth short circuit on the cable between station A and
station B .23
8.3 Three single-core cables .26
8.3.1 Line-to-earth short circuit in station B .26
8.3.2 Line-to-earth short circuit on the cable between station A and
station B .26
Annex A (informative) Example for the calculation of two separate simultaneous line-
to-earth short-circuit currents.30
Annex B (informative) Examples for the calculation of partial short-circuit currents
through earth .33
Annex C (informative) Example for the calculation of the reduction factor r and the
current distribution through earth in case of a three-core cable .43
Annex D (informative) Example for the calculation of the reduction factor r and the
current distribution through earth in case of three single-core cables .48

60909-3 © IEC:2009 – 3 –
Figure 1 – Driving point impedance Z of an infinite chain, composed of the earth wire
P
'
impedance Z =Zd and the footing resistance R of the towers, with equal
T
QQ T
distances d between the towers.9
T
Figure 2 – Driving point impedance Z of a finite chain with n towers, composed of the
Pn
'
earth wire impedance Z =Z d , the footing resistance R of the towers, with equal
T
Q Q T
distances d between the towers and the earthing impedance Z of station B from
T EB
Equation (29) .10
Figure 3 – Characterisation of two separate simultaneous line-to earth short circuits
"
and the currents I .12
kEE
Figure 4 – Partial short-circuit currents in case of a line-to-earth short circuit inside
station B .
Figure 5 – Partial short-circuit currents in case of a line-to-earth short circuit at a
tower T of an overhead line .16
Figure 6 – Distribution of the total current to earth I .17
ETtot
Figure 7 – Partial short–circuit currents in the case of a line-to-earth short circuit at a
tower n of an overhead line in the vicinity of station B .18
Figure 8 – Reduction factor r for overhead lines with non-magnetic earth wires
depending on soil resistivity ρ .21
Figure 9 – Reduction factor of three-core power cables .23
Figure 10 – Reduction factors for three single-core power cables .27
Figure A.1 – Two separate simultaneous line-to-earth short circuits on a single fed
overhead line (see Table 1) .
...