1、BSI Standards PublicationShort-circuit currents in three-phase a.c systemsPart 3: Currents during two separate simultaneous line-to-earth short-circuits and partial short-circuit currents flowing through earthBS EN 60909-3:2010BS EN 60909-3:2010Incorporating corrigendum September 2013BS EN 60909-3:2
2、010 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 60909-3:2010. It isidentical to IEC 60909-3:2009, incorporating corrigendum September 2013.It supersedes BS EN 60909-3:2003 which is withdrawn.The start and finish of text introduced or altered by corrigendum i
3、s indicatedin the text by tags. Text altered by IEC corrigendum September 2013 is indic-ated in the text by .The UK participation in its preparation was entrusted to TechnicalCommittee PEL/73, Short circuit currents.A list of organizations represented on this committee can be obtainedon request to i
4、ts secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 84438 6ICS 17.220.01; 29.020; 29.240.20Compliance with
5、a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 30 April 2010.Amendments/corrigenda issued since publicationDate Text affected31 October 2013 Implementation of IEC corrigendum Se
6、ptember 2013EUROPEAN STANDARD EN 60909-3 NORME EUROPENNE EUROPISCHE NORM March 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: Avenue Marnix 17, B - 1000 Brussel
7、s 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 ICS 17.220.01; 29.240.20 Supersedes EN 60909-3:2003English version Short-circuit currents in three-phase a.c systems - Part 3: Currents during two separate simu
8、ltaneous line-to-earth short-circuits and partial short-circuit currents flowing through earth (IEC 60909-3:2009) Courants de court-circuit dans les rseaux triphass courant alternatif - Partie 3: Courants durant deux courts-circuits monophass simultans spars la terre et courants de court-circuit par
9、tiels scoulant travers la terre (CEI 60909-3:2009) Kurzschlussstrme in Drehstromnetzen - Teil 3: Strme bei Doppelerdkurzschluss und Teilkurzschlussstrme ber Erde (IEC 60909-3:2009) This European Standard was approved by CENELEC on 2010-03-01. CENELEC members are bound to comply with the CEN/CENELEC
10、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 CENEL
11、EC 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.
12、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, Roma
13、nia, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60909-3:2010EN 60909-3:2010 - 2 - 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 approv
14、ed 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
15、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 lin
16、es 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 red
17、uction 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 a
18、ll 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 national standard or by endorsement (dop) 2010-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow
19、) 2013-03-01 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. _ BS EN 60909-3:2010EN 60909-3:2010- 3 - EN 60909-3:2010 Annex ZA (normative) Normative references to
20、 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
21、 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. systems - Part 0: Calculation of currents EN 60909
22、-0 2001 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 - - BS EN 60909-3:2010BS EN 60909-3:2010EN 60909-3:2010 2 60909-3 IEC:2009 CONTENTS 1 Scope and object7 2 Normative references .8 3 Terms and d
23、efinitions .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 )( 1M and )( 2M .12 5.1.2 Simple cases of two separate simultaneous line-to-earth short circuits.13 5.2 Peak
24、 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 circuits14 6 Calculation of partial short-circuit currents flowing through earth in case of an unbalance
25、d short circuit14 6.1 General .14 6.2 Line-to-earth short circuit inside a station 15 6.3 Line-to-earth short circuit outside a station16 6.4 Line-to-earth short circuit in the vicinity of a station.18 6.4.1 Earth potential UETnat the tower n outside station B 19 6.4.2 Earth potential of station B d
26、uring 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 ends21 8.1 Overview .21 8.2 Three-core cable .22 8.2.1 Line-to-e
27、arth short circuit in station B 22 8.2.2 Line-to-earth short circuit on the cable between station A and station B23 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 B26 Annex A (informative
28、) Example for the calculation of two separate simultaneous line-to-earth short-circuit currents30 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 r1and the current distribu
29、tion through earth in case of a three-core cable.43 Annex D (informative) Example for the calculation of the reduction factor r3and the current distribution through earth in case of three single-core cables 48 BS EN 60909-3:2010BS EN 60909-3:201060909-3 IEC:200960909-3 IEC:2009 3 Figure 1 Driving po
30、int impedance ZPof an infinite chain, composed of the earth wire impedance QQZ Zd=Tand the footing resistance RTof the towers, with equal distances dTbetween the towers.9 Figure 2 Driving point impedance ZPnof a finite chain with n towers, composed of the earth wire impedance TQQdZZ = , the footing
31、resistance RTof the towers, with equal distances dTbetween the towers and the earthing impedance ZEBof station B from Equation (29)10 Figure 3 Characterisation of two separate simultaneous line-to earth short circuits and the currents “kEEI .12 Figure 4 Partial short-circuit currents in case of a li
32、ne-to-earth short circuit inside station B .15 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 ETtotI 17 Figure 7 Partial shortcircuit currents in the case of a line-to-earth shor
33、t 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 .21 Figure 9 Reduction factor of three-core power cables 23 Figure 10 Reduction factors for three single-core power c
34、ables .27 Figure A.1 Two separate simultaneous line-to-earth short circuits on a single fed overhead line (see Table 1) 30 Figure B.1 Line-to-earth short circuit inside station B System diagram for stations A, B and C 34 Figure B.2 Line-to-earth short circuit inside station B Positive-, negative- an
35、d zero-sequence systems with connections at the short-circuit location F within station B.34 Figure B.3 Line-to-earth short circuit outside stations B and C at the tower T of an overhead line System diagram for stations A, B and C .36 Figure B.4 Line-to-earth short circuit outside stations B and C a
36、t the tower T of an overhead line Positive-, negative- and zero-sequence systems with connections at the short-circuit location F.37 Figure B.5 Earth potentials uETn= UEtn /UETwith UET= 1,912 kV and uEBn= UEbn /UEB with UEB= 0,972 kV, if the line-to-earth short circuit occurs at the towers n = 1, 2,
37、 3, . in the vicinity of station B42 Figure C.1 Example for the calculation of the cable reduction factor and the current distribution through earth in a 10-kV-network, Un= 10 kV; c = 1,1; f = 50 Hz 44 Figure C.2 Short-circuit currents and partial short-circuit currents through earth for the example
38、 in Figure C.1.45 Figure C.3 Example for the calculation of current distribution in a 10-kV-network with a short circuit on the cable between A and B (data given in C.2.1 and Figure C.1).46 Figure C.4 Line-to-earth short-circuit currents, partial currents in the shield and partial currents through e
39、arth47 Figure D.1 Example for the calculation of the reduction factor and the current distribution in case of three single-core cables and a line-to-earth short circuit in station B .49 Figure D.2 Positive-, negative- and zero-sequence system of the network in Figure D.1 with connections at the shor
40、t-circuit location (station B) .50 Figure D.3 Current distribution for the network in Figure D.1, depending on the length, , of the single-core cables between the stations A and B51 BS EN 60909-3:2010BS EN 60909-3:201060909-3 IEC:2009 4 60909-3 IEC:2009 Figure D.4 Example for the calculation of the
41、reduction factors 3r and the current distribution in case of three single-core cables and a line-to-earth short circuit between the stations A and B .52 Figure D.5 Positive-, negative- and zero-sequence system of the network in Figure D.4 with connections at the short-circuit location (anywhere betw
42、een the stations A and B) 52 Figure D.6 Current distribution for the cable in Figure D.4 depending on A, REF.54 Figure D.7 Current distribution for the cable in Figure D.4 depending on A, REF= 5 56 Table 1 Calculation of initial line-to-earth short-circuit currents in simple cases 13 Table 2 Resisti
43、vity of the soil and equivalent earth penetration depth 20 Table C.1 Results for the example in Figure C.1 45 Table C.2 Results for the example in Figure C.3, km5=l .47 Table C.3 Results for the example in Figure C.3, km10=l .47 BS EN 60909-3:2010BS EN 60909-3:201060909-3 IEC:200960909-3 IEC:2009 7
44、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 1 Scope and object This part of IEC 60909 specifies procedures for calculation of the prospective short-circuit cur
45、rents with an unbalanced short circuit in high-voltage three-phase a.c. systems operating at nominal frequency 50 Hz or 60 Hz, i. e.: a) currents during two separate simultaneous line-to-earth short circuits in isolated neutral or resonant earthed neutral systems; b) partial short-circuit currents f
46、lowing 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
47、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. The standard does not cover: a) short-circuit currents deliberately created under controlled conditions as in short circuit testing stations, or
48、b) short-circuit currents in the electrical installations on board ships or aeroplanes, or c) single line-to-earth fault currents in isolated or resonant earthed systems. The object of this standard is to establish practical and concise procedures for the calculation of line-to-earth short-circuit c
49、urrents during two separate simultaneous line-to-earth short circuits and partial short-circuit currents through earth, earth wires of overhead lines and sheaths or shields of cables leading to conservative results with sufficient accuracy. For this purpose, the short-circuit currents are determined by considering an equivalent voltage source at the short-circuit location with all other voltage sources set to zero. Resista
