1、g44g40g40g40g3g54g87g71g3g23g22g22g140g16g21g19g19g28g3g11g53g72g89g76g86g76g82g81g3g82g73g3g44g40g40g40g3g54g87g71g3g23g22g22g16g20g28g26g23g12g44g40g40g40g3g53g72g70g82g80g80g72g81g71g72g71g3g51g85g68g70g87g76g70g72g3g73g82g85g44g81g86g88g79g68g87g76g82g81g3g55g72g86g87g76g81g74g3g82g73g3g36g38g3g
2、40g79g72g70g87g85g76g70g48g68g70g75g76g81g72g85g92g3g90g76g87g75g3g43g76g74g75g3g57g82g79g87g68g74g72g3g68g87g3g57g72g85g92g47g82g90g3g41g85g72g84g88g72g81g70g92g44g40g40g40g3g51g82g90g72g85g3g9g3g40g81g72g85g74g92g3g54g82g70g76g72g87g92g3g54g83g82g81g86g82g85g72g71g3g69g92g3g87g75g72g40g79g72g70g87
3、g85g76g70g3g48g68g70g75g76g81g72g85g92g3g38g82g80g80g76g87g87g72g72g44g40g40g40g22g3g51g68g85g78g3g36g89g72g81g88g72g3g49g72g90g3g60g82g85g78g15g3g49g60g3g20g19g19g20g25g16g24g28g28g26g15g3g56g54g36g3g3g21g23g3g41g72g69g85g88g68g85g92g3g21g19g20g19g23g22g22g55g48IEEE Std 433-2009 (Revision of IEEE S
4、td 433-1974) IEEE Recommended Practice for Insulation Testing of AC Electric Machinery with High Voltage at Very Low Frequency Sponsor Electric Machinery Committee of the IEEE Power +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be
5、 obtained through the Copyright Clearance Center. Introduction This introduction is not part of IEEE Std 433-2009, IEEE Recommended Practice for Insulation Testing of AC Electric Machinery with High Voltage at Very Low Frequency. Voltage withstand tests, particularly in the field, are generally carr
6、ied out with dc power sources, because in terms of weight, size, and cost they have a decided advantage. However the dc test data obtained on ac machines have a serious disadvantage in that the dc breakdown mechanism differs appreciably from that which occurs under ac conditions. In practice, it is
7、found that the dc breakdown strength is substantially higher than the ac breakdown strength. The dc breakdown process is principally an electronic conduction mechanism, with the free electrons injected into the insulation from either sharp points or the electrodes (where high field enhancement is cr
8、eated) or at space charge build-up sites within the dielectric. In contradistinction, the ac breakdown process involves a thermally controlled-type mechanism and results directly either from the thermal losses associated with the dielectric losses or from the partial discharge (PD) induced heating a
9、nd physical erosion mechanism at the sites where repeated discharges can take place. Both of these are frequency- and voltage-dependent effects; also note that the dissipation factor at a given insulation site is determined by the dielectric losses of both the solid insulation and the power loss con
10、tribution from the repetitive PD pulses. Evidently, it is more meaningful to evaluate the insulating systems of ac machines using ac voltage sources. For tests in the field, such ac voltage sources must be readily transportable, low weight, moderate size, and requiring lower amounts of power. This i
11、s accomplished by making use of low-frequency ac power supplies, which were first introduced in the 1950s for the purpose of high-potential testing and insulation resistance and capacitance measurements (see Bhimani B3, B4).aAlthough since that time, the low-frequency source equipment has undergone
12、substantial improvements, some uncertainties remain when it is attempted to relate the test data obtained at low frequencies to that at power frequencies. This becomes particularly apparent when one considers the dissipation factor and PD measurements at low frequencies with respect to those at the
13、power frequency. The dissipation factor may be expressed by the quotient, /, where represents the conductivity, represents the real permittivity (dielectric constant) of the dielectric, and is the frequency term. At power frequencies under constant ambient temperature, the conductivity is more or le
14、ss constant and governed by the conduction losses of free-charge carriers. Since is also relatively constant, then as the frequency is first decreased , the dissipation factor will exhibit an increase with falling frequency, . Once the falling frequency enters the space charge polarization region ov
15、er the lower frequencies, the conductivity will commence increasing, thereby further augmenting the value of the dissipation factor. As a consequence, the low-frequency value of the dissipation factor will be substantially higher than that at the power frequencies (see Engineering Dielectrics, Vol.
16、IIB, Electrical Properties of Solid Insulating Materials: Measurement Techniques B5). When diagnostic measurements are carried out in terms of the dissipation factor to determine the dielectric loss behavior of an insulating system, it must be borne in mind that the measured tan value is an indicato
17、r of the total loss in the insulating system. The PD contribution can be calculated in terms of the PD pulse-phase distribution at a given applied voltage and frequency or be measured using the pulse charge-voltage parallelogram technique (see Engineering Dielectrics, Vol. I, Corona Measurement and
18、Interpretation B6). The dielectric loss component in the solid insulation of the ac machine can then be determined by subtracting the dissipation factor value due to the PD loss from that resulting from that of the overall insulation system loss. a The numbers in brackets correspond to those of the
19、bibliography in Annex C. iv Copyright 2010 IEEE. All rights reserved. The PD intensity at power frequencies is substantially greater than at 0.1 Hz, because there are more discharges occurring per unit time, i.e., per 1 s, at 60 Hz. However, it is most remarkable that studies, which have been carrie
20、d out over an extended frequency range, indicate that as the frequency of the power source is reduced, the total PD pulse charge transfer per cycle is augmented as the number of PD pulses per cycle exhibits an increase with falling frequency (see Bartnikas and Morin B2 and Radu et al. B18. It is lik
21、ely that the observed behavior is due to the change in the rate of dielectric surface charging and discharging within the cavities. Nevertheless, the total PD energy dissipated over a 1 s period at the power frequency is appreciably higher than that at 0.1 Hz; if the ac breakdown strength at 60 Hz i
22、s a result of thermal instability and degradation caused by PDs, then it will be lower than that at 0.1 Hz, which in turn will be still lower than the dc breakdown strength. Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance w
23、ith the provisions of this standard does not imply compliance to any applicable regulatory requirements. Implementers of the standard are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that i
24、s not in compliance with applicable laws, and these documents may not be construed as doing so. Copyrights This document is copyrighted by the IEEE. It is made available for a wide variety of both public and private uses. These include both use, by reference, in laws and regulations, and use in priv
25、ate self-regulation, standardization, and the promotion of engineering practices and methods. By making this document available for use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to this document. Updating of IEEE documents Users of IEEE sta
26、ndards should be aware that these documents may be superseded at any time by the issuance of new editions or may be amended from time to time through the issuance of amendments, corrigenda, or errata. An official IEEE document at any point in time consists of the current edition of the document toge
27、ther with any amendments, corrigenda, or errata then in effect. In order to determine whether a given document is the current edition and whether it has been amended through the issuance of amendments, corrigenda, or errata, visit the IEEE Standards Association web site at http:/ieeexplore.ieee.org/
28、xpl/standards.jsp, or contact the IEEE at the address listed previously. For more information about the IEEE Standards Association or the IEEE standards 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 accesse
29、d at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. v Copyright 2010 IEEE. All rights reserved. vi Copyright 2010 IEEE. All rights reserved. Interpretations Current interpretations can be accessed at
30、 the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this recommended practice may require use of subject matter covered by patent rights. By publication of this recommended practice, no position is taken
31、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 inquiries into the legal validity or scope of Patents Claims or determining whether any lice
32、nsing 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 recommended practice are expressly advised that determination of the validity of any patent rights, and the risk of in
33、fringement 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 submitted to the IEEE-SA Standards Board for approval, the Insulation Testing of AC Electric Machinery with
34、 High Voltage at Very Low Frequency Working Group had the following membership: Howard Sedding, Chair Stefano G. Bomben, Vice Chair Sabir Azizi Ray Bartnikas Martin Baur Kevin Becker William Chen Sudhakar Cherukupalli Douglas Conley Alfredo Contin Shawn Filliben George Gao Jim Grant Vince Green Bal
35、Gupta Guy Halldorson Gary Heuston Jeff Hubrig Lou Little Bill McDermid Beant Nindra Lori Rux Mladin Sasic Joe Williams Chuck Wilson Karim Younsi Hugh Zhu Deceased vii Copyright 2010 IEEE. All rights reserved. The following members of the individual balloting committee voted on this recommended pract
36、ice. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman Michael Adams Ali Al Awazi Paul Barnhart David Baron Martin Baur William Bloethe Stuart Borlase Steven Brockschink Chris Brooks Andrew Brown Thomas Callsen Antonio Cardoso Weijen Chen Danila Chernetsov Tommy
37、Cooper John Crouse Jorge Fernandez Daher Matthew Davis Gary L. Donner Donald Dunn Gary Engmann Randall Groves Ajit Gwal Steve Hamilton Gary Heuston David Horvath Joseph L. Koepfinger Jim Kulchisky Saumen Kundu William Lockley G. Luri Omar Mazzoni William McDermid Nigel McQuin G. Harold Miller Kimber
38、ly Mosley Michael S. Newman Lorraine Padden Iulian Profir Michael Roberts Dinesh Sankarakurup Bartien Sayogo Gregory Stone Meredith Stranges S. Thamilarasan Martin Von Herrmann Joe Watson Chuck Wilson James Wilson Hugh Zhu Ahmed Zobaa When the IEEE-SA Standards Board approved this recommended practi
39、ce on 9 December 2009, it had the following membership: Robert M. Grow, Chair Thomas Prevost, Vice Chair Steve M. Mills, Past Chair Judith Gorman, Secretary John Barr Karen Bartleson Victor Berman Ted Burse Richard DeBlasio Andy Drozd Mark Epstein Alexander Gelman Jim Hughes Richard H. Hulett Young
40、Kyun Kim Joseph L. Koepfinger* John Kulick David J. Law Ted Olsen Glenn Parsons Ronald C. Petersen Narayanan Ramachandran Jon Walter Rosdahl Sam Sciacca *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Howard L. Wolfman, TAB Representative Michael Janezic,
41、 NIST Representative Satish Aggarwal, NRC Representative Lisa Perry IEEE Standards Program Manager, Document Development Soo H. Kim IEEE Standards Program Manager, Technical Program Development viii Copyright 2010 IEEE. All rights reserved. Contents 1. Overview 1 1.1 Scope . 1 1.2 Purpose 1 1.3 Back
42、ground 2 2. Normative references 2 3. Definitions 3 4. Preparations for test 4 4.1 General 4 4.2 Air-cooled machines 4 4.3 Hydrogen-cooled machines . 5 4.4 Liquid-cooled stator (armature) windings . 5 4.5 Oil-cooled machines 5 4.6 Isolation of the winding from cables and auxiliary equipment 5 4.7 Se
43、ctionalizing the winding 6 4.8 Equipment clearances and area isolation . 6 4.9 Grounding precautions. 6 5. General test considerations . 7 5.1 Possibility of failure to pass test 7 5.2 Condition of winding . 7 5.3 Test voltage determination 7 6. Test equipment . 8 6.1 Equipment specifications . 8 6.
44、2 Instrumentation 8 6.3 Protection of equipment and test specimen . 8 6.4 Power source to the very low frequency test equipment . 8 6.5 Operation check . 8 6.6 Ground connections . 9 6.7 High-voltage test connections 9 7. Test procedure 9 7.1 Overpotential tests . 9 7.2 Diagnostic tests 9 8. Test re
45、sults 10 8.1 Interpretation . 10 8.2 Suggested test record . 10 8.3 Record comments regarding 10 ix Copyright 2010 IEEE. All rights reserved. Annex A (informative) Information on testing . 11 Annex B (informative) Glossary 16 Annex C (informative) Bibliography 17 IEEE Recommended Practice for Insula
46、tion Testing of AC Electric Machinery with High Voltage at Very Low Frequency IMPORTANT NOTICE: This standard is not intended to ensure safety, security, health, or environmental protection in all circumstances. Implementers of the standard are responsible for determining appropriate safety, securit
47、y, environmental, and health practices or regulatory requirements. This IEEE document is made available for use subject 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”
48、or “Important Notices and Disclaimers Concerning IEEE Documents.” They can also be obtained on request from IEEE or viewed at http:/standards.ieee.org/IPR/disclaimers.html. 1. Overview 1.1 Scope This document describes very low frequency (VLF) testing of ac electric machines. It covers acceptance te
49、sting of new machines in the factory or on-site after erection. Also covered is the routine maintenance testing of machines that have been in service. In order to facilitate communication and comparison among investigators, this document recommends that the VLF used be 0.1 Hz 10%. 1.2 Purpose The purposes of this recommended practice are as follows: a) To provide a uniform procedure for testing the stator (armature) insulation of ac electric machines with VLF voltage, in order to obtain consistent results b) To recommend constants for rela
