EN IEC 61788-24-2018 Superconductivity - Part 24 Critical current measurement - Retained critical current after double bending at room temperature of Ag-sheathe.pdf

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1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06SuperconductivityPart 24: Critical current measurement - Retained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wiresBS EN IEC 61788-24:2018EUROPEAN STANDARD NORME EURO

2、PENNE EUROPISCHE NORM EN IEC 61788-24 August 2018 ICS 29.050; 77.040.10; 17.220 English Version Superconductivity - Part 24: Critical current measurement - Retained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wires (IEC 61788-24:2018) Supraconduct

3、ivit - Partie 24: Mesurage du courant critique - Courant critique retenu aprs double flexion temprature ambiante des fils supraconducteurs Bi-2223 avec gaine Ag (IEC 61788-24:2018) Supraleitfhigkeit - Teil 24: Messung des kritischen Stroms - Verbleibender kritischer Strom nach Doppelbiegung bei Raum

4、temperatur in Ag-ummantelten Bi-2223 supraleitenden Drhten (IEC 61788-24:2018) This European Standard was approved by CENELEC on 2018-07-23. 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

5、national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German

6、). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium,

7、Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Swe

8、den, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CENELEC All rights of ex

9、ploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN IEC 61788-24:2018 E National forewordThis British Standard is the UK implementation of EN IEC 61788-24:2018. It is identical to IEC 61788-24:2018.The UK participation in its preparation was entrusted to Techn

10、ical Committee L/-/90, Super Conductivity.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 application. The British Standard

11、s Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0 580 94891 6ICS 77.040.10; 29.050; 17.220Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 A

12、ugust 2018.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN IEC 61788-24:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IEC 61788-24 August 2018 ICS 29.050; 77.040.10; 17.220 English Version Superconductivity - Part 24: Critical current measurement - Re

13、tained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wires (IEC 61788-24:2018) Supraconductivit - Partie 24: Mesurage du courant critique - Courant critique retenu aprs double flexion temprature ambiante des fils supraconducteurs Bi-2223 avec gaine

14、Ag (IEC 61788-24:2018) Supraleitfhigkeit - Teil 24: Messung des kritischen Stroms - Verbleibender kritischer Strom nach Doppelbiegung bei Raumtemperatur in Ag-ummantelten Bi-2223 supraleitenden Drhten (IEC 61788-24:2018) This European Standard was approved by CENELEC on 2018-07-23. CENELEC members a

15、re 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

16、 the CEN-CENELEC Management Centre 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 CEN-CENELEC Mana

17、gement Centre 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ir

18、eland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europ

19、isches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN IEC 61788-24:2018 E BS EN IEC 61788-24:2018EN IEC 61788-24:2018 (E

20、) 2 European foreword The text of document 90/402/FDIS, future edition 1 of IEC 61788-24, prepared by IEC/TC 90 “Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 61788-24:2018. The following dates are fixed: latest date by which the document has to

21、be implemented at national level by publication of an identical national standard or by endorsement (dop) 2019-04-23 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2021-07-23 Attention is drawn to the possibility that some of the elements of this

22、 document may be the subject of patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61788-24:2018 was approved by CENELEC as a European Standard without any modification. In the official ver

23、sion, for Bibliography, the following note has to be added for the standard indicated: IEC 61788-3 NOTE Harmonized as EN 61788-3 BS EN IEC 61788-24:2018EN IEC 61788-24:2018 (E) 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications Th

24、e following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.

25、 NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD Ye

26、ar IEC 60050-815 2015 International Electrotechnical Vocabulary - Part 815: Superconductivity - - BS EN IEC 61788-24:2018This page deliberately left blank 2 IEC 61788-24:2018 IEC 2018 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references 7 3 Terms and definitions 7 4 Principle 8 5

27、Apparatus 8 5.1 General . 8 5.2 Bending mandrel . 8 5.3 Critical current measurement holder . 8 5.4 Critical current measuring system . 9 6 Specimen preparation and set up 9 6.1 Length of specimen . 9 6.2 Mounting of the specimen . 10 7 Measurement procedures 10 7.1 Critical current measurement 10 7

28、.2 Double bending . 10 7.3 Retained critical current after bending . 11 8 Calculation of results . 11 8.1 Critical current criteria. 11 8.2 n-value (optional) 11 9 Test report . 11 9.1 Identification of test specimen . 11 9.2 Report of Icvalues and/or retained Icratio . 12 9.3 Report of Ictest condi

29、tions . 12 Annex A (informative) Additional information relating to Clauses 1 to 9 13 A.1 General . 13 A.2 Measurement condition . 13 A.3 Apparatus measurement holder material . 13 A.4 Specimen preparation . 16 A.5 Measurement procedures 16 A.5.1 Critical current measurement . 16 A.5.2 Bending . 18

30、A.6 Calculation of results 19 A.6.1 Critical current criteria . 19 A.6.2 n-value 19 A.7 Relative standard uncertainty 20 Annex B (informative) Evaluation of combined standard uncertainty for the retained Icafter double bending . 22 B.1 Practice of critical current measurement . 22 B.2 Model equation

31、 . 22 B.3 Operation for the retained Icmeasurement . 23 B.4 Combined standard uncertainty . 23 2 IEC 61788-24:2018 IEC 2018 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references 7 3 Terms and definitions 7 4 Principle 8 5 Apparatus 8 5.1 General . 8 5.2 Bending mandrel . 8 5.3 Crit

32、ical current measurement holder . 8 5.4 Critical current measuring system . 9 6 Specimen preparation and set up 9 6.1 Length of specimen . 9 6.2 Mounting of the specimen . 10 7 Measurement procedures 10 7.1 Critical current measurement 10 7.2 Double bending . 10 7.3 Retained critical current after b

33、ending . 11 8 Calculation of results . 11 8.1 Critical current criteria. 11 8.2 n-value (optional) 11 9 Test report . 11 9.1 Identification of test specimen . 11 9.2 Report of Icvalues and/or retained Icratio . 12 9.3 Report of Ictest conditions . 12 Annex A (informative) Additional information rela

34、ting to Clauses 1 to 9 13 A.1 General . 13 A.2 Measurement condition . 13 A.3 Apparatus measurement holder material . 13 A.4 Specimen preparation . 16 A.5 Measurement procedures 16 A.5.1 Critical current measurement . 16 A.5.2 Bending . 18 A.6 Calculation of results 19 A.6.1 Critical current criteri

35、a . 19 A.6.2 n-value 19 A.7 Relative standard uncertainty 20 Annex B (informative) Evaluation of combined standard uncertainty for the retained Icafter double bending . 22 B.1 Practice of critical current measurement . 22 B.2 Model equation . 22 B.3 Operation for the retained Icmeasurement . 23 B.4

36、Combined standard uncertainty . 23 BS EN IEC 61788-24:2018IEC 61788-24:2018 IEC 2018 3 B.5 Evaluation of standard uncertainty (SU) for each measurand 24 B.5.1 Voltage tap length (L) 24 B.5.2 Voltage (U) 24 B.5.3 Current (I) . 25 B.6 Evaluation of combined standard uncertainty 26 Bibliography 29 Figu

37、re 1 Sample holder 9 Figure 2 Intrinsic U-I characteristic 12 Figure 3 U-I characteristic with a current transfer component . 12 Figure A.1 Measurement configuration for a few hundred ampere class conductor . 15 Figure A.2 Clips . 15 Figure A.3 Additional strain caused by voltage tap wires and solde

38、rs . 16 Figure A.4 Boiling temperature of liquid nitrogen versus atmospheric pressure . 17 Figure A.5 Critical current versus temperature for a typical Bi-2223 wire 18 Figure A.6 Bending process . 19 Figure B.1 U-I diagram 22 Figure B.2 Bending diameter dependence of the retained Icand , where the c

39、alculated curve of Ic/Ic0gives Equation (B.24) 28 Table A.1 Thermal expansion data of Bi-2223 superconductors and selected materials . 14 Table A.2 Average of the degree of retained critical current (Ic/Ic0), their relative standard uncertainty and coefficient of variance 21 Table B.1 Precondition f

40、or evaluating standard uncertainty 22 Table B.2 Partial sum (Equation (B.17) of standard uncertainty as related to the current measurement) . 26 Table B.3 Budget table of standard uncertainty for each component 27 Table B.4 Combined standard uncertainty 27 BS EN IEC 61788-24:2018 4 IEC 61788-24:2018

41、 IEC 2018 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SUPERCONDUCTIVITY Part 24: Critical current measurement Retained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wires FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide

42、 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 electronic fields. To this end and in addition to other activi

43、ties, IEC publishes International Standards, Technical Specifications, 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 d

44、ealt with may participate in this preparatory work. International, 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 determin

45、ed by agreement between the two organizations. 2) The formal 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 Committee

46、s. 3) IEC Publications have the form of recommendations for international 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 the

47、y are used or for any misinterpretation by any end user. 4) In 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 a

48、nd the corresponding national or regional publication shall be 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 resp

49、onsible 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 including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) an