1、BSI Standards Publication Short-circuit currents Calculation of effects Part 2: Examples of calculation PD IEC/TR 60865-2:2015National foreword This Published Document is the UK implementation of IEC/TR 60865-2:2015. It supersedes PD 6575-2:1995 which is withdrawn. The UK participation in its prepar
2、ation was entrusted to Technical Committee PEL/73, Short circuit currents. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct
3、 application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 84957 2 ICS 17.220.01; 29.020; 29.240.20 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Sta
4、ndards Policy and Strategy Committee on 31 May 2015. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TR 60865-2:2015IEC TR 60865-2 Edition 2.0 2015-04 TECHNICAL REPORT Short-circuit currents Calculation of effects Part 2: Examples of calculation INTERNATIO
5、NAL ELECTROTECHNICAL COMMISSION ICS 17.220.01; 29.240.20 ISBN 978-2-8322-2551-6 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. 2 IEC TR 60865-2:2015 IEC 2015 CONTENTS FOREWORD . 5 1 Scope 7 2
6、 Normative references . 7 3 Symbols and units 7 4 Example 1 Mechanical effects on a 10 kV arrangement with single rigid conductors . 8 4.1 General . 8 4.2 Data 9 4.3 Normal load case: Conductor stress and forces on the supports caused by dead load 9 4.4 Exceptional load case: Effects of short-circui
7、t currents 10 4.4.1 Maximum force on the central main conductor 10 4.4.2 Conductor stress and forces on the supports 11 4.5 Conclusions 13 5 Example 2 Mechanical effects on a 10 kV arrangement with multiple rigid conductors . 14 5.1 General . 14 5.2 Data (additional to the data of Example 1) . 14 5.
8、3 Normal load case: Conductor stress and forces on the supports caused by dead load 15 5.4 Exceptional load case: Effects of short-circuit currents 15 5.4.1 Maximum forces on the conductors 15 5.4.2 Conductor stress and forces on the supports 16 5.5 Conclusions 20 6 Example 3. Mechanical effects on
9、a high-voltage arrangement with rigid conductors . 20 6.1 General . 20 6.2 Data 21 6.3 Normal load case: Conductor stress and forces on the supports caused by dead load 22 6.4 Exceptional load case: Effects of short-circuit currents 23 6.4.1 Maximum force on the central main conductor 23 6.4.2 Condu
10、ctor stress and forces on the supports 23 6.4.3 Conclusions . 29 7 Example 4. Mechanical effects on a 110 kV arrangement with slack conductors 30 7.1 General . 30 7.2 Data 31 7.3 Electromagnetic load and characteristic parameters 32 7.4 Tensile force F t,dduring short-circuit caused by swing out . 3
11、4 7.5 Dynamic conductor sag at midspan . 35 7.6 Tensile force F f,dafter short-circuit caused by drop . 36 7.7 Horizontal span displacement b hand minimum air clearance a min. 36 7.8 Conclusions 36 8 Example 5. Mechanical effects on strained conductors 37 8.1 General . 37 8.2 Common data . 37 8.3 Ce
12、ntre-line distance between sub-conductors a s= 0,1 m . 38 PD IEC/TR 60865-2:2015 IEC TR 60865-2:2015 IEC 2015 3 8.3.1 Electromagnetic load and characteristic parameters . 38 8.3.2 Tensile force F t,dduring short-circuit caused by swing out . 41 8.3.3 Dynamic conductor sag at midspan 41 8.3.4 Tensile
13、 force F f,dafter short-circuit caused by drop . 42 8.3.5 Horizontal span displacement b hand minimum air clearance a min. 43 8.3.6 Pinch force F pi,d43 8.3.7 Conclusions . 43 8.4 Centre-line distance between sub-conductors a s= 0,4 m . 44 8.4.1 Preliminary remarks . 44 8.4.2 Characteristic dimensio
14、ns and parameters . 44 8.4.3 Pinch force F pi,d45 8.4.4 Conclusions . 47 9 Example 6 Mechanical effects on strained conductors with dropper in the middle of the span 47 9.1 General . 47 9.2 Common data . 48 9.3 Plane of the dropper parallel to the main conductors 48 9.3.1 General . 48 9.3.2 Current
15、flow along the whole length of the main conductor span . 49 9.3.3 Current flow along half of the length of the main conductor and along the dropper 57 9.4 Plane of the dropper perpendicular to the main conductors 64 9.4.1 General . 64 9.4.2 Current flow along the whole length of the main conductor s
16、pan . 64 9.4.3 Current flow along half of the length of the main conductor and along the dropper 69 10 Example 7 Mechanical effects on vertical main conductors (droppers) . 77 10.1 General . 77 10.2 Data 77 10.3 Short-circuit tensile force and maximum horizontal displacement . 78 10.4 Pinch force 78
17、 10.4.1 Static tensile force regarding droppers . 78 10.4.2 Characteristic dimensions and parameters . 79 10.4.3 Pinch force F pi,d80 10.5 Conclusions 81 11 Example 8 Thermal effect on bare conductors . 81 11.1 General . 81 11.2 Data 81 11.3 Calculations 82 11.4 Conclusion 82 Bibliography 83 Figure
18、1 Conductor arrangement 8 Figure 2 Position of the sub-conductors and connecting pieces . 14 Figure 3 Two-span arrangement with tubular conductors. 21 Figure 4 Arrangement with slack conductors . 31 Figure 5 Arrangement with strained conductors 37 Figure 6 Arrangement with strained conductors and dr
19、oppers in midspan. Plane of the droppers parallel to the main conductors . 47 PD IEC/TR 60865-2:2015 4 IEC TR 60865-2:2015 IEC 2015 Figure 7 Possible arrangement of perpendicular droppers in three-phase system and two-line system . 64 Figure 8 Arrangement with strained conductors 77 PD IEC/TR 60865-
20、2:2015 IEC TR 60865-2:2015 IEC 2015 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SHORT-CIRCUIT CURRENTS CALCULATION OF EFFECTS Part 2: Examples of calculation FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national elec
21、trotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifi
22、cations, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. Internatio
23、nal, governmental and non- governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal
24、decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for i
25、nternational use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) I
26、n order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall b
27、e clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certifica
28、tion 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 including individual experts and members of its technical committees and IEC National Committees for any personal injury,
29、 property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cite
30、d 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 elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifyin
31、g any or all such patent rights. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a technical report when it has collected data of a different kind from that which is normally published as an International
32、Standard, for example “state of the art“. IEC TR 60865-2, which is a technical report, has been prepared by IEC technical committee 73: Short-circuit currents. This second edition cancels and replaces the first edition published in 1994. This edition constitutes a technical revision. This edition in
33、cludes the following significant technical changes with respect to the previous edition. a) The determinations for auto reclosure together with rigid conductors have been revised. PD IEC/TR 60865-2:2015 6 IEC TR 60865-2:2015 IEC 2015 b) The configurations in cases of flexible conductor arrangements
34、have been changed. c) The influence of mid-span droppers to the span has been included. d) For vertical cable-connection the displacement and the tensile force onto the lower fixing point may be calculated now. e) Additional recommendations for foundation loads due to tensile forces have been added.
35、 f) The subclause for determination of the thermal equivalent short-circuits current has been deleted (is part of IEC 60909-0:2001 now). g) The standard IEC 60865-1:2011 has been reorganized and some of the symbols have been changed to follow the conceptual characteristic of international standards.
36、 The text of this technical report is based on the following documents: Enquiry draft Report on voting 73/168/DTR 73/173/RVC Full information on the voting for the approval of this technical report can be found in the report on voting indicated in the above table. This publication has been drafted i
37、n accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 60865 series, published under the general title Short-circuit currents Calculations of effects, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged unti
38、l the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingual version of this publication may be issued at a later d
39、ate. PD IEC/TR 60865-2:2015 IEC TR 60865-2:2015 IEC 2015 7 SHORT-CIRCUIT CURRENTS CALCULATION OF EFFECTS Part 2: Examples of calculation 1 Scope The object of this part of IEC 60865, which is a Technical Report, is to show the application of procedures for the calculation of mechanical and thermal e
40、ffects due to short circuits as presented in IEC 60865-1. Thus, this technical report is an addition to IEC 60865-1. It does not, however, change the basis for standardized procedures given in that publication. The following points should particularly be noted: a) The examples in this Technical Repo
41、rt illustrate how to make the calculations according to IEC 60865-1 in a simplified and easy-to-follow manner. They are not intended as a check for computer programs. b) The numbers in parentheses at the end of the equations refer to the equations in IEC 60865-1:2011. c) The system voltages are refe
42、rred to as nominal voltages. d) The results are rounded to three significant digits. e) Short-circuit effects appear as exceptional load in addition to the mechanical loads of the normal operation of a switchgear. In the following examples with rigid conductors, a possible static preloading is there
43、fore calculated too. Depending on whether it concerns the load of the normal operation or the load during the short-circuit different safety factors come to use. The height of these factors has been chosen typically and is recommended for the use. However, other safety factors may be necessary depen
44、ding on the safety concept. 2 Normative references IEC 60865-1:2011, Short-Circuit Currents Calculation of Effects Part 1: Definitions and calculation methods IEC 60909-0:2001, Short-circuit currents in three-phase AC systems Part 0: Calculation of currents 3 Symbols and units For symbols and units,
45、 reference is made to IEC 60865-1:2011. In addition, the following symbols are used: F str,kDead load (characteristic value) N F str,dDead load (design value) N F st,r,dForce on support of rigid conductors (design value) due to dead load N h S , h IHeight of the substructure, insulator m H sHorizont
46、al component of the force at the lower fixing point of one sub- conductor of a dropper N PD IEC/TR 60865-2:2015 8 IEC TR 60865-2:2015 IEC 2015 J st,mSecond moment of main conductor area with respect to the direction of the dead load m 4I kSteady-state short-circuit current (r.m.s) according to IEC 6
47、0909-0 A l effEffective length of a span m l fForm factor of a span m l hExtend of one head armature and clamp m m, n Factor for heat effect of the d.c. component and a.c. component 1 M S,d , M I,dBending moment on the bottom on the substructure, insulator (design value) Nm V sVertical component of
48、the force at the upper fixing point of one sub- conductor of a dropper N W st,mSection modulus of main conductor with respect to the direction of the dead load m 3g FPartial safety factor for action 1 g MPartial safety factor for material property 1 st,m,dBending stress caused by the dead load (desi
49、gn value) N/m 2 st,m,kBending stress caused by the dead load (characteristic value) N/m 24 Example 1 Mechanical effects on a 10 kV arrangement with single rigid conductors 4.1 General The basis for the calculation in this example is a three-phase 10 kV busbar with one conductor per phase. The conductors are continuous beams with equidistant simple supports. The conductor arrangement is shown in Figure 1. According to IEC 61936-1 1 1 , the calculation is done for the
