1、BRITISH STANDARD BS EN 60071-2:1997 IEC 71-2:1996 Insulation co-ordination Part 2: Application guide The European Standard EN60071-2:1997 has the status of a British Standard ICS 29.080.01BSEN 60071-2:1997 This British Standard, having been prepared under the Electrotechnical Sector Board, waspublis
2、hed under the authority of the Standards Boardand comes into effect on 15April1997 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference GEL/28 Draft for comment 90/26440 DC ISBN 0 580 27358 X Committees responsible for this British Standard The preparatio
3、n of this British Standard was entrusted to Technical Committee GEL/28, Insulation co-ordination, upon which the following bodies were represented: Association of Consulting Engineers British Cable Makers Association Electrical and Electronic Insulation Association (BEAMA Ltd.) Electricity Associati
4、on Transmission and Distribution Association (BEAMA Ltd.) Amendments issued since publication Amd. No. Date CommentsBS EN 60071-2:1997 BSI 11-1998 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 60071-2 5 List of references Inside back coverBSEN 6
5、0071-2:1997 ii BSI 11-1998 National foreword This Part of BSEN60071 has been prepared by Technical Committee GEL/28, and is the English language version of EN 60071-2:1997, Insulation co-ordination Part2: Application guide, published by the European Committee for Electrotechnical Standardization (CE
6、NELEC). It is identical with IEC71-2:1996, published by the International Electrotechnical Commission (IEC). It supersedes BS5622-2:1979 which is withdrawn. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their
7、 correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard HD 588.1 S1:1991 BS 923 Guide on high-voltage test techniques (IEC 60-1:1989) Part 1:1990 General EN 60071-1:199
8、5 BS EN 60071 Insulation co-ordination (IEC 71-1:1993) Part 1:1996 Definitions, principles and rules EN 60099-1:1994 BS EN 60099 Surge arresters (IEC 99-1:1991) Part 1:1994 Non-linear resistor type gapped surge arresters for a.c systems EN 60099-4:1993 (IEC99-4:1991) Part 4:1993 Metal-oxide surge ar
9、resters without gaps for a.c. systems EN 60507:1993 BS EN 60507:1993 Artificial pollution tests on high-voltage insulators to be used on a.c. systems (IEC 507:1991) BS 7527 Classification of environmental conditions HD 478.2.3 S1:1990 Part 2: Environmental conditions appearing in nature (IEC 721-2-3
10、:1987) Section 2.3:1991 Air pressure Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 106, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. T
11、his will be indicated in the amendment table on theinside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60071-2 January 1997 ICS 29.080.00 Supersedes HD 450.2 S1:1991 and partly supersedes HD 540.3 S1:1991 Descriptors: Insulation co-ordination, a.c. high-voltage network, voltage s
12、tress, insulation withstand, protective device, co-ordination between stresses and withstand English version Insulation co-ordination Part2: Application guide (IEC 71-2:1996) Coordination de lisolement Partie 2: Guide dapplication (CEI 71-2:1996) Isolationskoordination Teil 2: Anwendungsrichtlinie (
13、IEC 71-2:1996) This European Standard was approved by CENELEC on 1996-10-01. 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 b
14、ibliographical 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 responsib
15、ility 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Neth
16、erlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B 1050 Brussels 1997 CEN
17、ELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref. No. EN 60071-2:1996 EEN60071-2:1997 BSI 11-1998 2 Foreword The text of document 28/115/FDIS, future edition3of IEC71-2, prepared by IECTC28, Insulation co-ordination, was submitted to the IEC-CEN
18、ELEC parallel vote and was approved by CENELEC as EN60071-2 on 1996-10-01. This European Standard supersedes HD 540.2 S1:1991 and, together with EN 60071-1:1995, supersedes HD 540.3 S1:1991. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes
19、designated “informative” are given for information only. In this standard, annexes A and ZA are normative and annexes B to J are informative. Annex ZA has been added by CENELEC. Endorsement notice The text of the International Standard IEC71-2:1996 was approved by CENELEC as a European Standard with
20、out any modification. Contents Page Foreword 2 1 General 5 1.1 Scope 5 1.2 Normative references 5 1.3 List of symbols and definitions 5 2 Representative voltage stresses in service 10 2.1 Origin and classification of voltage stresses 10 2.2 Characteristics of overvoltage protective devices 10 2.3 Re
21、presentative voltages and overvoltages 12 3 Co-ordination withstand voltage 23 3.1 Insulation strength characteristics 23 3.2 Performance criterion 27 3.3 Insulation co-ordination procedures 27 4 Required withstand voltage 34 4.1 General remarks 34 4.2 Atmospheric correction 35 4.3 Safety factors 36
22、 5 Standard withstand voltage and testing procedures 37 5.1 General remarks 37 5.2 Test conversion factors 38 5.3 Determination of insulation withstand by type tests 39 6 Special considerations for overhead lines 42 6.1 General remarks 42 6.2 Insulation co-ordination for operating voltages and tempo
23、rary overvoltages 43 6.3 Insulation co-ordination for slow-front overvoltages 43 6.4 Insulation co-ordination for lightning overvoltages 43 7 Special considerations for substations 44 7.1 General remarks 44 7.2 Insulation co-ordination for overvoltages 45 Annex A (normative) Clearances in air to ass
24、ure a specified impulse withstand voltage installation 47 Annex B (informative) Determination of temporary overvoltages due to earth faults 49 Annex C (informative) Weibull probability distributions 53 latest date by which the ENhas to be implemented at national level by publication of an identical
25、national standard or by endorsement (dop) 1997-09-01 latest date by which the national standards conflicting with the ENhave to be withdrawn (dow) 1997-09-01EN60071-2:1997 BSI 11-1998 3 Page Annex D (informative) Determination of the representative slow-front overvoltage due to line energization and
26、 re-energization 57 Annex E (informative) Transferred overvoltages in transformers 65 Annex F (informative) Lightning overvoltages 71 Annex G (informative) Calculation of air gap breakdown strength from experimental data 78 Annex H (informative) Examples of insulation co-ordination procedure 82 Anne
27、x J (informative) Bibliography 104 Annex ZA (normative) Normative references to international publications with their corresponding European publications 105 Figure 1 Range of 2% slow-front overvoltages at the receiving end due to line energization and re-energization 16 Figure 2 Ratio between the 2
28、% values of slow-front overvoltages phase-to-phase and phase-to-earth 17 Figure 3 Diagram for surge arrester connection to the protected object 22 Figure 4 Distributive discharge probability of self-restoring insulation described on a linear scale 30 Figure 5 Disruptive discharge probability of self
29、-restoring insulation described on a Gaussian scale 31 Figure 6 Evaluation of deterministic co-ordination factor K cd 31 Figure 7 Evaluation of the risk of failure 32 Figure 8 Risk of failure of external insulation for slow-front overvoltages as a function of the statistical co-ordination factor K c
30、s34 Figure 9 Dependence of exponent m on the co-ordination switching impulse withstand voltage 36 Figure 10 Probability P of an equipment to pass the test dependent on the difference K between the actual and the rated impulse withstand voltage 41 Figure 11 Example of a schematic substation layout us
31、ed for the overvoltage stress location (see 7.1) 44 Figure B.1 Earth-fault factor k on a base of X 0 /X 1for R 1 /X 1= R = 0 50 Page Figure B.2 Relationship between R 0 /X 1and X 0 /X 1for constant values of earth-fault factor k where R 1= 0 51 Figure B.3 Relationship between R 0 /X 1et X 0 /X 1for
32、constant values of earth-fault factor k where R 1= 0,5 X 1 51 Figure B.4 Relationship between R 0 /X 1et X 0 /X 1for constant values of earth-fault factor k where R 1= X 1 52 Figure B.5 Relationship between R 0 /X 1et X 0 /X 1for constant values of earth-fault factor k where R 1= 2X 1 52 Figure C.1
33、Conversion chart for the reduction of the withstand voltage due to placing insulation configurations in parallel 57 Figure D.1 Example for bivariate phase-to-phase overvoltage curves with constant probability density and tangents giving the relevant 2% values 62 Figure D.2 Principle of the determina
34、tion of the representative phase-to-phase overvoltage U pre 63 Figure D.3 Schematic phase-phase-earth insulation configuration 64 Figure D.4 Description of the 50% switching impulse flashover voltage of a phase-phase-earth insulation 64 Figure D.5 Inclination angle of the phase-to-phase insulation c
35、haracteristic in range b dependent on the ratio of the phase-phase clearance D to the height Ht above earth 65 Figure E.1 Distributed capacitances of the windings of a transformer and the equivalent circuit describing the windings 70 Figure E.2 Values of factor J describing the effect of the winding
36、 connections on the inductive surge transference 71 Table 1 Recommended creepage distances 29 Table 2 Test conversion factors for range I, to convert required switching impulses withstand voltages to short-duration power-frequency and lightning impulse withstand voltages 39 Table 3 Test conversion f
37、actors for range II to convert required short-duration power-frequency withstand voltages to switching impulse withstand voltages 39 Table 4 Selectivity of test procedures B and C of IEC60-1 41EN60071-2:1997 BSI 11-1998 4 Page Table A.1 Correlation between standard lightning impulse withstand voltag
38、es and minimum air clearances 48 Table A.2 Correlation between standard switching impulse withstand voltages and minimum phase-to-earth air clearances 49 Table A.3 Correlation between standard switching impulse withstand voltages and minimum phase-to-phase air clearances 49 Table C.1 Breakdown volta
39、ge versus cumulative flashover probability Single insulation and 100 parallel insulations 55 Table F.1 Corona damping constant K co73 Table F.2 Factor A for various overhead lines 77 Tableau G.1 Typical gap factors K for switching impulse breakdown phase-to-earth 81 Table G.2 Gap factors for typical
40、 phase-to-phase geometries 82 Table H.1 Summary of minimum requiredwithstand voltages obtained for exampleH.1.1 87 Table H.2 Summary of required withstand voltages obtained for example H.1.2 90 Table H.3 Values related to the insulation co-ordination procedure for example H.3 103EN60071-2:1997 BSI 1
41、1-1998 5 1 General 1.1 Scope This part of IEC71 constitutes an application guide and deals with the selection of insulation levels of equipment or installations for three-phase electrical systems. Its aim is to give guidance for the determination of the rated withstand voltages for ranges I and II o
42、f IEC71-1 and to justify the association of these rated values with the standardized highest voltages for equipment. This association is for insulation co-ordination purposes only. The requirements for human safety are not covered by this application guide. It covers three-phase systems with nominal
43、 voltages above 1kV. The values derived or proposed herein are generally applicable only to such systems. However, the concepts presented are also valid for two-phase or single-phase systems. It covers phase-to-earth, phase-to-phase and longitudinal insulation. This application guide is not intended
44、 to deal with routine tests. These are to be specified by the relevant product committees. The content of this guide strictly follows the flow chart of the insulation co-ordination process presented in Figure 1 of IEC71-1. Clauses2 to5 correspond to the squares in this flow chart and give detailed i
45、nformation on the concepts governing the insulation co-ordination process which leads to the establishment of the required withstand levels. The guide emphasizes the necessity of considering, at the very beginning, all origins, all classes and all types of voltage stresses in service irrespective of
46、 the range of highest voltage for equipment. Only at the end of the process, when the selection of the standard withstand voltages takes place, does the principle of covering a particular service voltage stress by a standard withstand voltage apply. Also, at this final step, the guide refers to the
47、correlation made in IEC71-1 between the standard insulation levels and the highest voltage for equipment. The annexes contain examples and detailed information which explain or support the concepts described in the main text, and the basic analytical techniques used. 1.2 Normative references The fol
48、lowing normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC71. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements based on this part of IEC71 are
49、encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 56:1987, High-voltage alternating-current circuit-breakers. IEC 60-1:1989, High-voltage test techniques Part1: General definitions and test requirements. IEC 71-1:1993, Insulation co-ordination Part1:Definitions, principles and rules. IEC 99-1:1991, Surge arresters
