1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationPower transformersPart 2: Temperature rise for liquid-immersed transformersBS EN 60076-2:2011National forewordThis British Standard is the UK implementation of EN 60076-2:2011. I
2、t is identical to IEC 60076-2:2011. It supersedes BS EN 60076-2:1997 which The UK participation in its preparation was entrusted to Technical Committee PEL/14, Power transformers.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does n
3、ot purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011ISBN 978 0 580 60092 0 ICS 29.180Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of th
4、e Standards Policy and Strategy Committee on 31 May 2011.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60076-2:2011will be withdrawn 30 March 2014.EUROPEAN STANDARD EN 60076-2 NORME EUROPENNE EUROPISCHE NORM April 2011 CENELEC European Committee for Electrotechn
5、ical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 6007
6、6-2:2011 E ICS 29.180 Supersedes EN 60076-2:1997English version Power transformers - Part 2: Temperature rise for liquid-immersed transformers (IEC 60076-2:2011) Transformateurs de puissance - Partie 2: Echauffement des transformateurs immergs dans le liquide (CEI 60076-2:2011) Leistungstransformato
7、ren - Teil 2: bertemperaturen fr flssigkeitsgefllte Transformatoren (IEC 60076-2:2011) This European Standard was approved by CENELEC on 2011-03-30. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the stat
8、us 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 CENELEC member. This European Standard exists in three official versions (English, French, German).
9、 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. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cr
10、oatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60076-2:2011
11、EN 60076-2:2011 - 2 - Foreword The text of document 14/669/FDIS, future edition 3 of IEC 60076-2, prepared by IEC TC 14, Power transformers, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60076-2 on 2011-03-30. This European Standard supersedes EN 60076-2:1997. EN 6
12、0076-2:2011 includes the following significant technical changes with respect to EN 60076-2:1997: the standard is applicable only to liquid immersed transformers; the winding hot-spot temperature rise limit was introduced among the prescriptions; the modalities for the temperature rise test were imp
13、roved in relation to the new thermal requirements; five informative annexes were added in order to facilitate the standard application. 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
14、for identifying any or all 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) 2011-12-30 latest date by which the national standards conflicting with the EN h
15、ave to be withdrawn (dow) 2014-03-30 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60076-2:2011 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be add
16、ed for the standards indicated: 2 IEC 60296:2003 NOTE Harmonized as EN 60296:2004 (not modified). 3 IEC 60567:2005 NOTE Harmonized as EN 60567:2005 (not modified). 4 IEC 60599:1999 NOTE Harmonized as EN 60599:1999 (not modified). 5 IEC 60836:2005 NOTE Harmonized as EN 60836:2005 (not modified). 6 IE
17、C 61099:2010 NOTE Harmonized as EN 61099:2010 (not modified). _ BS EN 60076-2:2011- 3 - EN 60076-2:2011 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of t
18、his document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD appli
19、es. Publication Year Title EN/HD Year IEC 60076-1 (mod) - Power transformers - Part 1: General EN 60076-1 - IEC 60076-8 1997 Power transformers - Part 8: Application guide - - IEC 60085 2007 Electrical insulation - Thermal evaluation and designation EN 60085 2008 IEC 61181 2007 Mineral oil-filled el
20、ectrical equipment - Application of dissolved gas analysis (DGA) to factory tests on electrical equipment EN 61181 2007 IEC Guide 115 2007 Application of uncertainty of measurement to conformity assessment activities in the electrotechnical sector - - BS EN 60076-2:2011 2 60076-2 IEC:2011 CONTENTS 1
21、 Scope . . 6 2 Normative references . 6 3 Terms and definitions . 6 4 Cooling methods . 8 4.1 Identification symbols . 8 4.2 Transformers with alternative cooling methods . . 9 5 Normal cooling conditions. 9 5.1 Air-cooled transformers 9 5.2 Water-cooled transformers 10 6 Temperature rise limits . 1
22、0 6.1 General . . 10 6.2 Temperature rise limits at rated power 10 6.3 Modified requirements for special cooling conditions 12 6.3.1 General . 12 6.3.2 Air-cooled transformers 12 6.3.3 Water-cooled transformers . . 13 6.4 Temperature rise during a specified load cycle 13 7 Temperature rise tests 13
23、7.1 General . . 13 7.2 Temperature of the cooling media . 13 7.2.1 Ambient temperature . . 13 7.2.2 Water temperature . 14 7.3 Test methods for temperature rise determination . 14 7.3.1 General . 14 7.3.2 Test by short-circuit method for two winding transformers. . 14 7.3.3 Test modification for par
24、ticular transformers . 15 7.4 Determination of liquid temperatures . 16 7.4.1 Top-liquid temperature . 16 7.4.2 Bottom and average liquid temperatures 17 7.5 Determination of top, average and bottom liquid temperature rises . . 18 7.6 Determination of average winding temperature 18 7.7 Determination
25、 of winding resistance at the instant of shutdown 19 7.8 Determination of average winding temperature rise at the instant of shutdown . . 19 7.9 Determination of the average winding to liquid temperature gradient . 19 7.10 Determination of the hot-spot winding temperature rise . 20 7.10.1 General .
26、20 7.10.2 Determination by calculation . . 20 7.10.3 Direct measurement during the temperature rise test . . 20 7.11 Uncertainties affecting the results of the temperature rise test. . 21 7.12 Dissolved gas-in-oil analysis . . 21 7.13 Corrections. 21 Annex A (informative) Hot-spot winding temperatur
27、e rise determination for OFAF and OFWF cooled transformers based on the top-liquid temperature in tank . 23 Annex B (informative) Methods to estimate the hot-spot winding temperature rises. 25 BS EN 60076-2:201160076-2 IEC:2011 3 Annex C (informative) Techniques used in temperature rise testing of l
28、iquid-immersed transformers . 30 Annex D (informative) Dissolved gases analysis for the detection of local overheating . 39 Annex E (informative) Application of optical fibre sensors for winding hot-spot measurements . . 43 Bibliography . 47 Figure B.1 Temperature rise distribution model for ON cool
29、ing methods . 26 Figure B.2 Value of factor Q as a function of rated power and strand height (W) . . 27 Figure B.3 Typical liquid flow paths in a disk winding with diverting washers 28 Figure C.1 Recommended circuit for transformers with a low resistance winding using two separate direct current sou
30、rces, one for each winding 32 Figure C.2 Alternative recommended circuit using only one direct current source for both windings. . 32 Figure C.3 Average winding temperature variation after shutdown . 33 Figure C.4 Extrapolation of the cooling down curve, using the fitting curve ( )w0wt/TBe ktA t+= .
31、 38 Figure E.1 Optical fibre sensor application for a disk winding of core type transformer . 45 Figure E.2 Optical fibre sensor application for a transposed cable of core type transformer 45 Figure E.3 Modality of optical fibre sensor application in the winding spacer of core type transformer . 46
32、Figure E.4 Optical fibre sensor application for high voltage winding of shell type transformer 46 Table 1 Temperature rise limits . 11 Table 2 Recommended values of temperature rise corrections in case of special service conditions . . 12 Table 3 Exponents for the corrections of temperature rise tes
33、t results . . 22 Table A.1 Hot-spot winding temperature rises for some specific transformers determined from conventional heat run test data combined with calculated hot-spot winding temperature rise, and from direct fibre-optic measurements . 24 Table C.1 Example of cooling down curve calculation s
34、preadsheet 37 Table D.1 Minimum detectable value SDof gases in oil 40 Table D.2 Admissible limits for gas rate increases 41 Table E.1 Minimum recommended number of sensors for three-phase transformers . . 43 Table E.2 Minimum recommended number of sensors for single-phase transformers . 43 BS EN 600
35、76-2:2011 6 60076-2 IEC:2011 POWER TRANSFORMERS Part 2: Temperature rise for liquid-immersed transformers 1 Scope This part of IEC 60076 applies to liquid-immersed transformers, identifies power transformers according to their cooling methods, defines temperature rise limits and gives the methods fo
36、r temperature rise tests. 2 Normative references 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 any amendments) applies.
37、IEC 60076-1, Power transformers Part 1: General IEC 60076-8:1997, Power transformers Part 8: Application guide IEC 60085:2007, Electrical insulation Thermal evaluation and designation IEC 61181:2007, Mineral oil-filled electrical equipment Application of dissolved gas analysis (DGA) to factory tests
38、 on electrical equipment IEC Guide 115:2007, Application of uncertainty of measurement to conformity assessment activities in the electrotechnical sector 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60076-1 and the following apply. 3.1 external co
39、oling medium the medium external to the transformer cooling system (air or water) into which the heat produced by the transformer losses is transferred 3.2 internal cooling medium the liquid in contact with the windings and other transformer parts by means of which the heat produced by the losses is
40、 transferred to the external cooling medium NOTE The liquid can be mineral oil or other natural and synthetic liquid. 3.3 temperature rise the difference between the temperature of the part under consideration (for example, the average winding temperature) and the temperature of the external cooling
41、 medium BS EN 60076-2:201160076-2 IEC:2011 7 3.4 top-liquid temperature othe temperature of the insulating liquid at the top of the tank, representative of top-liquid in the cooling flow stream 3.5 top-liquid temperature rise o the temperature difference between the top-liquid temperature and the ex
42、ternal cooling medium temperature 3.6 bottom-liquid temperature bthe temperature of the insulating liquid as measured at the height of the bottom of the windings or to the liquid flowing from the liquid cooling equipment 3.7 bottom-liquid temperature rise b the difference between the bottom-liquid t
43、emperature and the external cooling medium temperature 3.8 average liquid temperature omthe average temperature of the top-liquid and bottom liquid temperatures 3.9 average liquid temperature rise om the difference between the average liquid temperature and the external cooling medium temperature 3.
44、10 average winding temperature w the winding temperature determined at the end of temperature rise test from the measurement of winding d.c. resistance 3.11 average winding temperature rise w the difference between the average winding temperature and the external cooling medium temperature 3.12 aver
45、age winding gradient gthe difference between the average winding temperature and the average insulating liquid temperature BS EN 60076-2:2011 8 60076-2 IEC:2011 3.13 hot-spot winding temperature hthe hottest temperature of winding conductors in contact with solid insulation or insulating liquid 3.14
46、 hot-spot winding temperature rise h the difference between hot-spot winding temperature and the external cooling medium temperature 3.15 hot-spot factor Ha dimensionless factor to estimate the local increase of the winding gradient due to the increase of additional loss and variation in the liquid
47、flow stream NOTE H factor is obtained by the product of the Q and S factors (see 3.16 and 3.17). 3.16 Q factor a dimensionless factor to estimate the increase of the average winding gradient due to the local increase of the additional loss 3.17 S factor a dimensionless factor to estimate the local i
48、ncrease of the average winding gradient due to the variation in the liquid flow stream 3.18 thermally upgraded paper cellulose-based paper which has been chemically modified to reduce the rate at which the paper decomposes A paper is considered as thermally upgraded if it meets the life criteria of
49、the 50 % retention in tensile strength after 65 000 h in a sealed tube at 110 C or any other time/temperature combination given by the equation: +=273 11000015273 00015he 00065(h)Time (1) NOTE 1 Ageing effects are reduced either by partial elimination of water forming agents or by inhibiting the formation of water through the use of stabilizing agents. NOTE 2 See IEC 60076-7, for an alternative test method base
