1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-18815-3 SANS 61378-3:2007Edition 1IEC 61378-3:2006Edition 1SOUTH AFRICAN NATIONAL STANDARD Converter transformers Part 3: Application guid
4、e This national standard is the identical implementation of IEC 61378-3:2006 and is adopted with the permission of the International Electrotechnical Commission. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 intern
5、ational code + 27 12 www.stansa.co.za Standards South Africa SANS 61378-3:2007 Edition 1 IEC 61378-3:2006 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA TC 69, Power electronics and alternative energy conversio
6、n, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This part of SANS 61378 was published in February 2007 . NORME INTERNATIONALECEIIECINTERNATIONAL STANDARD 61378-3Premire ditionFirst edition2006-04Transformateurs de conversion Partie 3:
7、Guide dapplication Converter transformers Part 3: Application guide Pour prix, voir catalogue en vigueur For price, see current catalogue IEC 2006 Droits de reproduction rservs Copyright - all rights reserved Aucune partie de cette publication ne peut tre reproduite ni utilise sous quelque forme que
8、 ce soit et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de lditeur. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in
9、writing from the publisher. International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.ch CODE PRIX PRICE CODE XC Commission Electrotechnique InternationaleInternationa
10、l Electrotechnical Commission SANS 61378-3:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 3 CONTENTS FOREWORD.7 INTRODUCTION.11 1 Scope.17 2 Normative references .17 3 Terms and definitions .19 4 Symbols and abbreviation
11、s.19 5 Rating data.21 6 Winding configurations .21 6.1 General .21 6.2 Industrial applications25 6.3 HVDC applications 33 7 Tappings and impedances HVDC applications.39 7.1 Value of impedance.39 7.2 Variability of impedance 39 8 Insulation aspects and dielectric tests 41 8.1 Hybrid insulation system
12、s41 8.2 Dielectric tests 45 9 Losses53 9.1 General .53 9.2 Thermal tests 75 10 Core and sound aspects.77 10.1 Core77 10.2 Sound .79 11 Transformer specification .83 11.1 General .83 11.2 Technical specification versus functional specifications.85 11.3 HVDC transformer specifications.85 11.4 Notes an
13、d comments on specification items to be provided individually by purchaser and supplier87 11.5 Information to be provided by the supplier .87 11.6 Quality assurance and test programme .95 11.7 Availability and measures to minimize service downtime .95 11.8 Information to be provided by the purchaser
14、 or by the system designer.95 12 Short circuit considerations 113 13 Components .121 13.1 On-load tap-changers121 13.2 Valve-side bushings 123 14 Maintenance.131 14.1 General .131 14.2 Oil .133 14.3 Insulation quality .135 14.4 Tap-changers 145 14.5 Accessories and fittings.147 SANS 61378-3:2007This
15、 s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 5 15 Monitoring 149 15.1 General .149 15.2 Transformer condition assessment in service 149 15.3 Types of monitor .151 15.4 Summary.159 Bibliography161 Figure 1 Bridge connection for
16、 six-pulse arrangement23 Figure 2 Bridge connection for twelve-pulse arrangement 23 Figure 3 Transformer connections star-delta and star-star or alternatively, delta-delta and delta-star to give a 30 electrical degree separation between the valve-side voltages23 Figure 4 15 phase shifting is prefera
17、bly realized by extended delta or zigzag connection. .25 Figure 5 Connection of self-saturated reactors.27 Figure 6 Autotransformer concept for open phases 29 Figure 7 Conventional autotransformer concept for closed phases with coarse and fine regulation for small regulating steps.29 Figure 8 Booste
18、r arrangement for autotransformer concept for closed phases with coarse and fine regulation for small regulating steps.31 Figure 9 Delta connection with tapped windings.31 Figure 10 Two winding design with tapped winding 33 Figure 11 Two basic arrangements of the individual windings of a two-winding
19、 transformer .35 Figure 12 Mutual impedance39 Figure 13 Typical impedance pattern .41 Figure 14 Components of a typical industrial converter transformer insulating system43 Figure 15 Insulation system, equivalent R-C circuit47 Figure 16 Voltage distribution before and immediately after polarity reve
20、rsal .49 Figure 17 AC/DC conversion Simplified sketch51 Figure 18 Leakage fields for a three-winding transformer with closely coupled valve windings .63 Figure 19 Leakage fields for a three-winding transformer with decoupled valve windings .65 Figure 20 Leakage fields for a three winding transformer
21、 with loosely coupled double concentric valve windings .67 Figure 21 Leakage fields for a three winding transformer with loosely coupled double-tier valve windings.69 Figure 22 Short-circuit fault conditions .115 Figure 23 Arrangement of valve bushings 127 Figure 24 Examples of a.c., d.c. and combin
22、ed electric field dispositions adjacent to HVDC bushings and associated electric insulation systems 129 Table 1 Arrangements of two windings.35 SANS 61378-3:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 7 INTERNATIONAL
23、ELECTROTECHNICAL COMMISSION _ CONVERTER TRANSFORMERS Part 3: Application guide FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promot
24、e 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 Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (h
25、ereafter 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. International, governmental and non-governmental organizations liaising with the IEC also p
26、articipate 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 decisions or agreements of IEC on technical matters express, as nearly as possible
27、, 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 international use and are accepted by IEC National Committees in that sense. While
28、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) In order to promote international uniformity, IEC National Committees undertake to
29、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 be clearly indicated in the latter. 5) IEC provides no marking procedure to indicat
30、e its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 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 in
31、dividual 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) and expenses arising out of the publication, use of, or reliance upo
32、n, 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 elements
33、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 61378-3 has been prepared by IEC technical committee 14: Power transformers. The text of this standard is based on the following do
34、cuments: FDIS Report on voting 14/529/FDIS 14/534/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. SANS 61378-3:2007This s tanda
35、rd may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 9 IEC 61378 consists of the following parts, under the general title Converter transformers: Part 1: Transformers for industrial applications Part 2: Transformers for HVDC applications Part
36、 3: Application guide The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed
37、; withdrawn; replaced by a revised edition, or amended. SANS 61378-3:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 11 INTRODUCTION 0 General IEC 61378 is written in three parts: Part 1 applies to transformers associated
38、 with general “Industrial“ converter uses. (Copper making, aluminium smelting and the electrolysis of certain gases). Part 2 applies to transformers required for HVDC applications. Part 3 is this application guide which contains the topic headings described in 0.2 to 0.12. IEC 61378-1 applies to con
39、verter transformers used in “industrial applications” and applies to transformers that supply electrolysis applications for aluminium smelting, copper refining and the production of certain gases. It also applies to electrical drives as used in rolling mill and ship propulsion systems. It does not a
40、pply to electrical drives in traction applications that are mounted on board locomotives but does apply to converter applications associated with static traction systems. In addition, there is a wide range of smaller rating converter duties to which Part 1 and the present part of IEC 61378 are equal
41、ly applicable. IEC 61378-2 covers converter transformers used in “HVDC Applications”. There are two types of HVDC power transmission systems known generically as “back to back” and “transmission” schemes. The operation and evaluation of transformers operating within these two systems are covered by
42、Part 2 and the present part of IEC 61378. 0.1 Rating data (Clause 5) In both IEC 61378-1 and IEC 61378-2, the method of rating converter transformers is different to that used historically. In the traditional method, the r.m.s. value of current was used in defining the nameplate rating of the transf
43、ormer. IEC 61378 has introduced a fundamental change in the method of defining the rating of transformers. The concept of using the fundamental components of voltage and current as the basis for the transformer nameplate rating is explained. The nameplate rating derived from these fundamental compon
44、ents becomes the basis for the guaranteed impedances and losses. 0.2 Winding configurations (Clause 6) There are a large number of winding connections and configurations that are specific to converter transformers for both industrial and HVDC applications. They have been developed over many years. T
45、he operating characteristics of the various rectifier connections are mostly covered in IEC 60146. In the present part of IEC 61378, the connections are discussed in so far as they affect the construction and some operational aspects of the transformer. The use of regulating schemes is common in ind
46、ustrial applications. The present part of IEC 61378 covers the principles for a number of these schemes. SANS 61378-3:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61378-3 IEC:2006 13 0.3 Tappings and impedances (Clause 7) The impedance
47、 of transformers for HVDC applications requires special attention and design solutions. The requirements primarily concern the limitation of the impedance variability over the whole tapping range, the limitation of the impedance difference between transformers and in some applications, the impedance
48、 difference between star and delta windings. This document discusses these requirements and their practical aspects. In general, the tapping range in converter transformers is wider than in conventional transformers. The impact of the wider tapping range on the transformer and the tap-changer is dis
49、cussed in this document. 0.4 Insulation aspects and dielectric tests (Clause 8) Two aspects are covered in this Clause. First, the increasing use of “hybrid” insulation systems in transformers for industrial applications. Secondly, the ability of transformer insulation structures of HVDC transformers when tested with d.c. voltage and in service. The basic principles, the methods of testing and the test voltage
