1、Overhead transmission lines Design criteriaBS IEC 60826:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis British Standard is the UK implementation of IEC 60826:2017.The UK participation in its preparation was entrusted to TechnicalCommittee P
2、EL/11, Overhead Lines.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2017.Pub
3、lished by BSI Standards Limited 2017ISBN 978 0 580 75509 5ICS 29.240.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2017.Amendments/corrigenda issu
4、ed since publicationDate Text affectedBRITISH STANDARDBS IEC 60826:2017IEC 60826 Edition 4.0 2017-02 INTERNATIONAL STANDARD Overhead transmission lines Design criteria INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.240.20 ISBN 978-2-8322-3884-4 Registered trademark of the International Electrotech
5、nical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colourinsideBS IEC 60826:2017 2 IEC 60826:2017 IEC 2017 CONTENTS FOREWORD . 7 1 Scope 9 2 Normative references 9 3 Terms, definitions, symbols and abbreviations . 9 3.1 Terms and definitions 9 3.2
6、Symbols and abbreviations . 12 4 General . 15 4.1 Objective 15 4.2 System design 15 4.3 System reliability . 16 5 General design criteria 16 5.1 Methodology . 16 5.1.1 General . 16 5.1.2 Reliability requirements . 17 5.1.3 Security requirements 19 5.1.4 Safety requirements. 19 5.2 Load-strength requ
7、irements 19 5.2.1 Climatic loads 19 5.2.2 Design requirements for the system . 20 5.2.3 Design formula for each component . 21 6 Loadings 22 6.1 Description . 22 6.2 Climatic loads, wind and associated temperatures 22 6.2.1 General . 22 6.2.2 Field of application 22 6.2.3 Terrain roughness . 23 6.2.
8、4 Reference wind speed VR. 23 6.2.5 Assessment of meteorological measurements 24 6.2.6 Determination from gradient wind velocities . 25 6.2.7 Combination of wind speed and temperatures 25 6.2.8 Number of supports subjected in wind action, effect of length of line . 26 6.2.9 Unit action of the wind s
9、peed on any line component or element . 26 6.2.10 Evaluation of wind loads on line components and elements . 27 6.3 Climatic loads, ice without wind 34 6.3.1 Description 34 6.3.2 Ice data . 34 6.3.3 Evaluation of yearly maximum ice load by means of meteorological data analysis . 35 6.3.4 Reference l
10、imit ice load . 36 6.3.5 Temperature during icing . 37 6.3.6 Loads on support . 37 6.4 Climatic loads, combined wind and ice loadings 39 6.4.1 General . 39 6.4.2 Combined probabilities Principle proposed . 39 6.4.3 Determination of ice load . 40 6.4.4 Determination of coincident temperature 40 BS IE
11、C 60826:2017IEC 60826:2017 IEC 2017 3 6.4.5 Determination of wind speed associated with icing conditions 40 6.4.6 Drag coefficients of ice-covered conductors . 41 6.4.7 Determination of loads on supports 42 6.5 Loads for construction and maintenance (safety loads) . 43 6.5.1 General . 43 6.5.2 Erect
12、ion of supports . 43 6.5.3 Construction stringing and sagging 44 6.5.4 Maintenance loads . 44 6.6 Loads for failure containment (security requirements) . 45 6.6.1 General . 45 6.6.2 Security requirements 45 6.6.3 Security related loads Torsional, longitudinal and additional security measures. 45 7 S
13、trength of components and limit states 47 7.1 General . 47 7.2 General formulas for the strength of components 47 7.2.1 General . 47 7.2.2 Values of strength factor N48 7.2.3 General basis for strength coordination . 49 7.2.4 Strength factor Srelated to the coordination of strength 50 7.2.5 Methods
14、for calculating strength coordination factors S. 50 7.3 Data related to the calculation of components . 51 7.3.1 Limit states for line components 51 7.3.2 Strength data of line components 54 7.3.3 Support design strength . 55 7.3.4 Foundation design strength . 56 7.3.5 Conductor and ground wire desi
15、gn criteria . 56 7.3.6 Insulator string design criteria 56 Annex A (informative) Technical information Strength of line components 58 A.1 Calculation of characteristic strength 58 Annex B (informative) Formulas of curves and figures . 60 B.1 General . 60 B.2 Formula for Gc Figure 4 . 60 B.3 Formula
16、for GL Figure 5 . 60 B.4 Formula for Gt Figure 6 60 B.5 Formula for Cxt Figure 8 (flat-sided members) . 60 B.6 Formula for Cxt Figure 9 (round-sided members) . 61 B.7 Formulas for Cxtc Figure 10 . 61 Annex C (informative) Atmospheric icing 62 C.1 General . 62 C.2 Precipitation icing . 62 C.2.1 Freez
17、ing rain . 62 C.2.2 Wet snow. 62 C.3 Dry ice 63 C.4 In-cloud icing 63 C.5 Physical properties of ice 64 C.6 Meteorological parameters controlling ice accretion 64 C.7 Terrain influences . 65 BS IEC 60826:2017 4 IEC 60826:2017 IEC 2017 C.7.1 In-cloud icing . 65 C.7.2 Precipitation icing 65 C.8 Guidel
18、ines for the implementation of an ice observation program 65 C.9 Ice data 67 C.9.1 Influence of height and conductor diameter 67 C.9.2 The effect of icing on structures . 67 C.10 Combined wind and ice loadings . 67 C.10.1 Combined probabilities 67 C.10.2 Drag coefficients of ice-covered conductors .
19、 68 Annex D (informative) Application of statistical distribution functions to load and strength of overhead lines . 69 Annex E (informative) Effect of span variation on load-strength relationship Calculation of span use factor . 71 E.1 General . 71 E.2 Effect of use factor on load reduction and its
20、 calculation . 72 Annex F (normative) Conductor tension limits 73 F.1 General . 73 F.2 Limits for lines with short spans 74 F.3 Recommended conductor limit tensions 74 F.3.1 Initial tension limit 74 F.3.2 Maximum final tension limit 75 F.4 Benefits from reducing conductor tensions 75 Annex G (inform
21、ative) Methods of calculation for wind speed up effects due to local topography 76 G.1 Application 76 G.2 Notes on application . 77 Bibliography 79 Figure 1 Diagram of a transmission line . 16 Figure 2 Transmission line design methodology . 17 Figure 3 Relationship between meteorological wind veloci
22、ties at a height of 10 m depending on terrain category and on averaging period 25 Figure 4 Combined wind factor Gcfor conductors for various terrain categories and heights above ground . 28 Figure 5 Span factor GL. 28 Figure 6 Combined wind factor Gt applicable to supports and insulator strings . 30
23、 Figure 7 Definition of the angle of incidence of wind 31 Figure 8 Drag coefficient Cxtfor lattice supports made of flat sided members 32 Figure 9 Drag coefficient Cxtfor lattice supports made of rounded members 32 Figure 10 Drag coefficient Cxtc of cylindrical elementshaving a large diameter . 33 F
24、igure 11 Factor Kdrelated to the conductor diameter . 36 Figure 12 Factor Khrelated to the conductor height . 37 a) Single circuit support 38 b) Double circuit support . 38 Figure 13 Typical support types . 38 Figure 14 Equivalent cylindrical shape of ice deposit . 42 Figure 15 Simulated longitudina
25、l conductor load (case of a single circuit support) . 46 BS IEC 60826:2017IEC 60826:2017 IEC 2017 5 Figure 16 Diagram of limit states of line components . 47 Figure C.1 Type of accreted in-cloud icing as a function of wind speed and temperature 64 Figure C.2 Strategy flow chart for utilizing meteoro
26、logical data, icing models and field measurements of ice loads 66 Figure G.1 Diagram of typical topographical cross-section . 77 Table 1 Reliability levels for transmission lines 18 Table 2 Default Tfactors for adjustment of climatic loads in relation to return period T versus 50 years . 20 Table 3
27、Design requirements for the system 21 Table 4 Classification of terrain categories . 23 Table 5 Factors describing wind action depending on terrain category . 24 Table 6 Correction factor of dynamic reference wind pressure q0due to altitude and temperatures 27 Table 7 Drag coefficient of polygonal p
28、ole sections 34 Table 8 Drag coefficient of structures having a triangular section . 34 Table 9 Statistical parameters of ice loads . 36 Table 10 Non-uniform ice loading conditions 39 Table 11 Return period of combined ice and wind load 40 Table 12 Drag coefficients of ice-covered conductors 41 Tabl
29、e 13 Additional security measures . 47 Table 14 Number of supports subjected to maximum load intensity during any single occurrence of a climatic event . 48 Table 15 Strength factor N related to the number N of components or elements subjected to the critical load intensity 49 Table 16 Values of S2.
30、 50 Table 17 Typical strength coordination of line components 50 Table 18 Damage and failure limits of supports 52 Table 19 Damage and failure limits of foundations . 53 Table 20 Damage and failure limits of conductors and ground wires 53 Table 21 Damage and failure limit of interface components 54
31、Table 22 Default values for strength coefficients of variation (COV) 55 Table 23 u factors for log-normal distribution function for e = 10 % . 55 Table 24 Value of quality factor Q for lattice towers . 56 Table A.1 Values of ue associated to exclusion limits . 59 Table C.1 Physical properties of ice
32、 . 64 Table C.2 Meteorological parameters controlling ice accretion . 64 Table C.3 Approximate values of ice weights on lattice structures 67 Table C.4 Combined wind and ice loading conditions . 68 Table C.5 Drag coefficients and density of ice-covered conductors 68 Table D.1 Parameters C1and C2of G
33、umbel distribution 69 Table D.2 Ratios of x / x for a Gumbel distribution function, T return period in years of loading event, n number of years with observations, vxcoefficient of variation 70 Table E.1 Use factor coefficient u. 72 BS IEC 60826:2017 6 IEC 60826:2017 IEC 2017 Table F.1 Variation of
34、conductor sag with catenary parameter C 74 Table F.2 Conductor tensioning recommended catenary parameter limits . 75 Table G. 1 Values of and 77 BS IEC 60826:2017IEC 60826:2017 IEC 2017 7 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ OVERHEAD TRANSMISSION LINES DESIGN CRITERIA FOREWORD 1) The Internat
35、ional Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electron
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42、as, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents includ
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44、ce upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the ele
45、ments of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 60826 has been prepared by IEC technical committee 11: Overhead lines. This fourth edition cancels and replaces the third edi
46、tion published in 2003. It constitutes a technical revision. The main technical changes with regard to the previous edition are as follows: This standard has been further simplified by removing many informative annexes and theoretical details that can now be found in CIGRE Technical Brochure 178 and
47、 referred to as needed in the text of the standard. Many revisions have also been made that reflect the users experience in the application of this standard, together with information about amplification of wind speed due to escarpments. The annexes dealing with icing data have also been updated usi
48、ng new work by CIGRE. BS IEC 60826:2017 8 IEC 60826:2017 IEC 2017 The text of this standard is based on the following documents: FDIS Report on voting 11/251/FDIS 11/252/RVD Full information on the voting for the approval of this International Standard can be found in the report on voting indicated
49、in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that the contents of this document will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific document. At this date, the document will be reconfirmed, withdrawn, rep
