1、IEEE Std C57.110-2008(Revision ofIEEE Std C57.110-1998)IEEE Recommended Practice forEstablishing Liquid-Filled and Dry-Type Power and DistributionTransformer Capability WhenSupplying Nonsinusoidal LoadCurrentsIEEE3 Park Avenue New York, NY 10016-5997, USA15 August 2008 IEEE Power Engineering Society
2、Sponsored by theTransformers CommitteeC57.110TMIEEE Std C57.110TM-2008 (Revision of IEEE Std C57.110-1998) IEEE Recommended Practice for Establishing Liquid-Filled and Dry- Type Power and Distribution Transformer Capability When Supplying Nonsinusoidal Load Currents Sponsor Transformers Committee of
3、 the IEEE Power Engineering Society Approved 27 March 2008 IEEE-SA Standards Board Abstract: This recommended practice provides calculation methods to conservatively evaluate the feasibility for an existing installed dry-type or liquid-filled transformer, to supply nonsinusoidal load currents as a p
4、ortion of the total load. This recommended practice also provides necessary application information to assist in properly specifying a new transformer expected to carry a load, a portion of which is composed of nonsinusoidal load currents. A number of examples illustrating these methods and calculat
5、ions are presented. Reference annexes provide a comparison of the document calculations to calculations found in other industry standards. Suggested temperature rise calculation methods are detailed for reference purposes. Keywords: accuracy, current transformer, instrument transformer, primary wind
6、ing, rated secondary voltage, routine tests, secondary winding, type tests, voltage transformer The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright 2008 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. P
7、ublished 15 August 2008. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. iv Copyright 200
8、8 IEEE. All rights reserved. Introduction (This introduction is not part of IEEE Std C57.110-2008, IEEE Recommended Practice for Establishing Liquid-Filled and Dry-Type Power and Distribution Transformer Capability When Supplying Nonsinusoidal Load Currents.) The widespread use of static rectificati
9、on equipment in industrial loads on small and medium power dry-type and liquid-filled transformers has resulted in a dramatic increase in the harmonic content of the load current of these transformers. It has become common for the harmonic factor of the current to exceed 0.05 per-unit, which is the
10、limit specified for “usual service conditions” in IEEE Std C57.12.00TMand IEEE Std C57.12.01TM. The higher harmonic content in the load current of these transformers causes higher eddy current loss in the windings and the structural parts linked by the transformer leakage flux and, consequently, hig
11、her operating temperatures. Users of this document should also recognize that liquid-filled transformers may have different load limitations than dry-type transformers and that the harmonic loading practices should treat the two types of transformers differently when necessary. This recommended prac
12、tice provides guidance for the conservative loading of transformers carrying nonsinusoidal load currents such that overheating is avoided. The intent of this document is to provide simple methods of calculating these effects on either a new transformer or an existing transformer. More specifically,
13、it is expected that this recommended practice would be used for the following situations: a) A new transformer required to carry some nonsinusoidal load currents, but will not be entirely devoted to a rectifier load. b) An existing transformer not originally specified for supplying nonsinusoidal loa
14、d currents, but is now required to supply a load, a portion of which is nonsinusoidal. Two methods are described in this recommended practice. The first method is intended to illustrate calculations by those with access to detailed information on loss density distribution within each of the transfor
15、mer windings. The second method is less accurate and is intended for use by those with access to transformer-certified test report data only. It is anticipated that the first method will emphasize the information necessary to specify a new transformer and show how this information is used by transfo
16、rmer design engineers, whereas the second method will be employed primarily by users. This recommended practice will provide methods for conservatively evaluating the feasibility of applying nonsinusoidal load currents to existing transformers and will clarify the requirements for specifying new tra
17、nsformers to supply nonsinusoidal loads. New transformers that are intended to supply loads with high harmonic content must be specified with a harmonic current distribution. The designer cannot “assume” nor can the user expect the designer to use “standard” or “typical” current distribution tables.
18、 If the harmonic content of the load is unknown, then both the user and the transformer designer are at risk and reasonable steps should be taken to ensure a conservative design for the application. Guidelines on how this information is used to develop proper transformer sizing is provided in this d
19、ocument, but appropriate calculations specific to the type of transformer design are the responsibility of the designer. Approximate calculation techniques that provide conservative results are provided for the typical user who has much less information than the transformer designer. v Copyright 200
20、8 IEEE. All rights reserved. Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance with the provisions of this standard does not imply compliance to any applicable regulatory requirements. Implementers of the standard are respons
21、ible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that is not in compliance with applicable laws, and these documents may not be construed as doing so. Copyrights This document is copyrighted by the IE
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24、ough the issuance of amendments, corrigenda, or errata. An official IEEE document at any point in time consists of the current edition of the document together with any amendments, corrigenda, or errata then in effect. In order to determine whether a given document is the current edition and whether
25、 it has been amended through the issuance of amendments, corrigenda, or errata, visit the IEEE Standards Association Web site at http:/ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE at the address listed previously. For more information about the IEEE Standards Association or the IEEE st
26、andards development process, visit the IEEE-SA Web site at http:/standards.ieee.org. Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:/ standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata perio
27、dically. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. vi Copyright 2008 IEEE. All rights reserved. Patents Attention is called to the possibility that implementation of this standard may require use of subject
28、 matter covered by patent rights. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE is not responsible for identifying Essential Patent Claims for which a license may be required, for conducting inqu
29、iries into the legal validity or scope of Patents Claims or determining whether any licensing terms or conditions provided in connection with submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory. Users of this standard are expressly advised
30、 that determination of the validity of any patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Further information may be obtained from the IEEE Standards Association. Participants At the time this recommended practice was completed, the C57.110 Working
31、Group had the following membership: Richard P. Marek, Chair N. Kent Haggerty, Vice Chair Nelson Alfonso Carl Bush Derek Foster Ramsis Girgis Philip Hopkinson Mike Iman Charles Johnson Sheldon Kennedy Timothy Lewis Walter Morehart Martin Navarro Hasse Nordman Dhiru Patel Mahesh Sampat Subhas Sarkar J
32、ohn SullivanThe following members of the balloting committee voted on this recommended practice. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman I. Antweiler Adam Bagby David Barnard Wallace Binder Thomas Bishop Thomas Blackburn Chris Brooks Carl Bush Thomas Ca
33、llsen Stephen Conrad Tommy Cooper Alan Darwin Dieter Dohnal Donald Dunn Gary Engmann Joseph Foldi Bruce Forsyth Marcel Fortin Saurabh Ghosh Jalal Gohari Edwin Goodwin Randall Groves N. Kent Haggerty Kenneth S. Hanus Roger Hayes Gary Heuston James Huddleston Charles Johnson Lars Juhlin Gael Kennedy S
34、heldon Kennedy Joseph L. Koepfinger Jim Kulchisky Saumen Kundu John Lackey Chung-Yiu Lam Stephen Lambert Lisardo Lourido G. Luri Keith N. Malmedal Richard P. Marek J. Dennis Marlow John W. Matthews Omar Mazzoni Jerry Murphy Joe Nims J. Patton Christopher Petrola Ugo Piovan Alvaro Portillo Iulian Pro
35、fir Michael Roberts Charles Rogers Oleg Roizman Dinesh Pranathy Sankarakurup Bartien Sayogo Devki Sharma Hyeong Sim Tarkeshwar Singh James E. Smith Jerry Smith Steve Snyder John Sullivan S. Thamilarasan John Vergis James Wilson William Wimmer Waldemar Ziomek vii Copyright 2008 IEEE. All rights reser
36、ved. When the IEEE-SA Standards Board approved this recommended practice on 27 March 2008, it had the following membership: Robert M. Grow, Chair Thomas A. Prevost, Vice Chair Steve M. Mills, Past Chair Judith Gorman, SecretaryVictor Berman Richard DeBlasio Andrew Drozd Mark Epstein Alex Gelman Will
37、iam R. Goldbach Arnold M. Greenspan Kenneth S. Hanus James Hughes Richard H. Hulett Young Kyun Kim Joseph L. Koepfinger* John Kulick David J. Law Glenn Parsons Ronald C. Petersen Narayanan Ramachandran Jon Rosdahl Anne-Marie Sahazizian Malcolm V. Thaden Howard L. Wolfman Don Wright *Member Emeritus
38、Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Michael H. Kelley, NIST Representative Lorraine Patsco IEEE Standards Program Manager, Document Development Matthew J. Ceglia IEEE Standards Program Manager, Technical Program Developme
39、nt viii Copyright 2008 IEEE. All rights reserved. Contents 1. Overview 1 1.1 Scope . 1 1.2 Purpose 1 2. Normative references 2 3. General considerations . 2 3.1 Transformer losses. 2 3.2 Transformer capability equivalent. 3 3.3 Basic data. 4 3.4 Transformer per-unit losses . 4 3.5 Transformer losses
40、 at measured currents. 5 3.6 Harmonic loss factorPT for winding eddy currents 7 3.7 Harmonic loss factor for other stray losses 10 4. Design considerations for new transformer specification. 12 4.1 Harmonic current filtering . 12 4.2 Impact on the neutral . 12 4.3 Power factor correction equipment 1
41、2 4.4 Electrostatic ground shields. 13 4.5 Design consideration outside the windings 13 4.6 Harmonic spectrum analysis 13 4.7 Design consideration in the windings 13 5. Recommended procedures for evaluating the load capability of existing transformersPT . 14 5.1 Transformer capability equivalent cal
42、culation using design eddy-current loss data 14 5.2 Transformer capability equivalent calculation using data available from certified test report 22 5.3 Typical calculations for dry-type transformers 24 5.4 Typical calculations for liquid-filled transformers 27 5.5 Neutral bus capability for nonsinu
43、soidal load currents that include third harmonic components . 30 Annex A (informative) Bibliography . 31 Annex B (informative) Comparison of UL K-factor definition and IEEE C57.110 harmonic loss factor definition 33 B.1 UL Definition of K-factor. 33 B.2 Relationship between K-factor and harmonic los
44、s factor 33 B.3 Example calculations 35 Annex C (informative) Temperature rise testing procedures 36 C.1 Preferred method of performing a temperature rise testPT 36 C.2 Alternative simulated load temperature rise testing proceduresPT 36 Annex D (informative) Tutorial discussion of transformer losses
45、 and the effect of harmonic currents on these losses . 42 1 Copyright 2008 IEEE. All rights reserved. IEEE Recommended Practice for Establishing Liquid-Filled and Dry- Type Power and Distribution Transformer Capability When Supplying Nonsinusoidal Load Currents IMPORTANT NOTICE: This standard is not
46、 intended to assure safety, security, health, or environmental protection in all circumstances. Implementers of the standard are responsible for determining appropriate safety, security, environmental, and health practices or regulatory requirements. This IEEE document is made available for use subj
47、ect to important notices and legal disclaimers. These notices and disclaimers appear in all publications containing this document and may be found under the heading “Important Notice” or “Important Notices and Disclaimers Concerning IEEE Documents.” They can also be obtained on request from IEEE or
48、viewed at http:/standards.ieee.org/IPR/disclaimers.html. 1. Overview 1.1 Scope This recommended practice applies only to two winding transformers covered by IEEE Std C57.12.00, IEEE Std C57.12.01, and NEMA ST20.1It does not apply to rectifier transformers. 1.2 Purpose The purpose of this document is
49、 to establish uniform methods for determining the capability of transformers to supply nonsinusoidal load currents of known characteristics. 1Information on references can be found in Clause 2. IEEE Std C57.110-2008 IEEE Recommended Practice for Establishing Liquid-Filled and Dry-Type Power and Distribution Transformer Capability When Supplying Nonsinusoidal Load Currents 2 Copyright 2008 IEEE. All rights reserved. 2. Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cit
