1、Rotating electrical machinery Natural graphite brush for slip-ring in wound rotor-typeinduction motor ApplicationinformationPD IEC/TR 63021:2016BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis Published Document is the UK implementation of IEC/TR
2、 63021:2016.The UK participation in its preparation was entrusted to TechnicalCommittee PEL/2, Rotating electrical machinery.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa
3、contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 91409 6ICS 29.160.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under th
4、e authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate Text affectedPUBLISHED DOCUMENTPD IEC/TR 63021:2016IEC TR 63021 Edition 1.0 2016-09 TECHNICALREPORT Rotating electrical machinery Natural graphite brush for slip-ring in
5、wound rotor-type induction motor Application information INTERNATIONALELECTROTECHNICALCOMMISSION ICS 29.160.01 ISBN 978-2-8322-3602-4 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. PD IEC/TR
6、63021:2016 2 IEC TR 63021:2016 IEC 2016 CONTENTS FOREWORD . 3 INTRODUCTION . 5 1 Scope . 6 2 Normative references. 6 3 Terms and definitions . 6 4 General remarks . 7 5 General conditions of brush and slip-ring for stability in the operation of a wound rotor-type induction motor . . 7 5.1 Fire-spark
7、 7 5.2 Life . 7 5.3 Temperature . 8 5.4 Dust diffusion 8 5.5 Noise 8 6 Operating characteristics of natural graphite brush for slip-ring in a wound rotor-type induction motor . 8 6.1 Current density . 8 6.2 Vibration absorbing ability . . 8 6.3 Temperature . 8 6.4 Brushs pressure . . 9 7 Testing met
8、hod . 9 8 Application result . 9 8.1 Fire-spark 9 8.2 Wear and life of brush . 9 8.3 Life of slip-ring 9 8.4 Environmental pollution . 9 8.4.1 Dust diffusion by wear of brush . 9 8.4.2 Pollution by noise . 10 8.5 Economic profit . . 10 8.5.1 Brush price . 10 8.5.2 Brush life . 10 8.5.3 No accident d
9、ue to dust diffusion and slip-rings life . 10 Annex A (informative) Data from practical application. 11 Bibliography . 12 Table 1 Typical kinds of brushes 7 Table 2 NG-brushs bulk density, electric resistivity and current density compared with the copper brush . 8 Table 3 Comparison of properties fo
10、r the assessment of vibration absorbing ability . . 8 Table 4 Wear and life of brush . 9 Table 5 Comparison of wear of NG-brush and copper brush . . 9 Table A.1 Data from practical application 11 PD IEC/TR 63021:2016IEC TR 63021:2016 IEC 2016 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ROTATING EL
11、ECTRICAL MACHINERY Natural graphite brush for slip-ring in wound rotor-type induction motor Application information FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committ
12、ees). The object of IEC is to promote internationalco-operation on all questions concerning standardization in the electrical and electronic fields. To this end and inaddition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,Publicly Available S
13、pecifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Theirpreparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt withmay participate in this preparatory work. International, governmental and non-governmental organizatio
14、ns liaisingwith the IEC also participate in this preparation. IEC collaborates closely with the International Organization forStandardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters e
15、xpress, as nearly as possible, an internationalconsensus of opinion on the relevant subjects since each technical committee has representation from allinterested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC NationalCommit
16、tees in that sense. While all reasonable efforts are made to ensure that the technical content of IECPublications is accurate, IEC cannot be held responsible for the way in which they are used or for anymisinterpretation by any end user. 4) In order to promote international uniformity, IEC National
17、Committees undertake to apply IEC Publicationstransparently to the maximum extent possible in their national and regional publications. Any divergence betweenany IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not pr
18、ovide any attestation of conformity. Independent certification bodies provide conformityassessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for anyservices carried out by independent certification bodies. 6) All users should ensure that they have the lat
19、est edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts andmembers of its technical committees and IEC National Committees for any personal injury, property damage orother damage of any nature whatsoever, wheth
20、er direct or indirect, or for costs (including legal fees) and expensesarising out of the publication, use of, or reliance upon, 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 isindis
21、pensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patentrights. IEC shall not be held responsible for identifying any or all such patent rights. The main task of IEC technical com
22、mittees is to prepare International Standards. However, atechnical committee may propose the publication of a Technical Report when it has collecteddata of a different kind from that which is normally published as an International Standard, forexample “state of the art“. IEC TR 63021, which is a Tec
23、hnical Report, has been prepared by IEC technical committee 2:Rotating machinery. The text of this Technical Report is based on the following documents: Enquiry draft Report on voting 2/1794/DTR 2/1823A/RVC Full information on the voting for the approval of this Technical Report can be found in the
24、reporton voting indicated in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. PD IEC/TR 63021:2016 4 IEC TR 63021:2016 IEC 2016 The committee has decided that the contents of this document will remain unchanged until thestability date indicated on th
25、e IEC website under “http:/webstore.iec.ch“ in the data related tothe specific document. At this date, the document will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingual version of this publication may be issued at a later date. PD IEC/TR 63021:2016IEC TR 63021:2016
26、IEC 2016 5 INTRODUCTION This Technical Report has been prepared after considering implications of the withdrawal ofIEC PAS 62072:2005 and its potential conversion into an International Standard, and afteranalysing practical information obtained through the application of natural graphite (NG) brushf
27、or slip-ring in wound-rotor type induction motor, compared with copper brush. Practical values obtained through the application of NG-brushes into slip-rings in various kindsof wound rotor-type induction motor are given in Annex A. PD IEC/TR 63021:2016 6 IEC TR 63021:2016 IEC 2016 ROTATING ELECTRICA
28、L MACHINERY Natural graphite brush for slip-ring in wound rotor-type induction motor Application information 1 Scope This document presents technical characteristics, application results and practical informationon NG-brush for slip-ring obtained through the application of NG-brush in various kinds
29、ofwound rotor-type induction motor (large-size water pump, belt conveyer, lift, winder motor,grinding mill and crusher in coal or ore mine; crane, rolling mill, compressor and winder motor forboring in oil or gas facility). 2 Normative references The following documents are referred to in the text i
30、n such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.For undated references, the latest edition of the referenced document (including anyamendments) applies. IEC 60413, Test procedures for determining physical p
31、roperties of brush materials for electricalmachines IEC 60773, Test methods and apparatus for measurement of the operational characteristics ofbrushes 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases f
32、or use in standardization at the followingaddresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp 3.1 fire-spark glittering phenomenon observed macroscopically between the brush and slip-ring during theoperation of a woun
33、d rotor-type induction motor 3.2 life critical time since the brushes have been installed into the wound rotor-type induction motorand started to operate until the brush and the slip-ring can no longer contribute to the motorsoperation 3.3 dust diffusion phenomenon whereby fine powders, caused by we
34、ar of the brush, diffuse in air during theoperation of a wound rotor-type induction motor PD IEC/TR 63021:2016IEC TR 63021:2016 IEC 2016 7 3.4 noise acoustic signal of high intensity caused between the brush and slip-ring among the acousticsignals of several wavelengths made during the operation of
35、a wound rotor-type inductionmotor 3.5 vibration absorbing ability ability of the brush to absorb or decrease electromagnetic and mechanical vibrations causedduring the operation of a wound rotor-type induction motor 4 General remarks Generally, it is traditional to use the metal grade brush includin
36、g copper brush for the woundrotor-type induction motor. The metal grade brush, including copper brushes, can usually damage the slip-ring by thefire-spark during operation. The dust generated by the wear of the copper brush can be thecause of accidents and also contaminates the environment. Compared
37、 with the formerly usedcopper brush, the NG-brush shows high operating characteristics when it is used for theslip-ring of a wound rotor-type induction motor. There is nearly no fire-spark between theNG-brush and slip-ring and no environmental pollution due to reduced wear. It also hassufficient abi
38、lity of electromotion. Table 1 shows the size and quantity of typical NG-brushes that are used for wound rotor-typeinduction motors of various powers. Table 1 Typical kinds of brushes No. Denomination Size Quantity (for a motor) Power mm kW 1 motor for elevator 253260 36 180 2 motor for compressor 2
39、53260 9 to 18 75 3 motor for winder 253260 9 to 18 250 4 motor for boring 253260 6 to 36 1 600 to 3 000 5 motor for grinding mill 253260 18 120 to 250 6 motor for crusher 253260 18 120 to 250 5 General conditions of brush and slip-ring for stability in the operation of awound rotor-type induction mo
40、tor 5.1 Fire-spark Fire-spark causes damage to the surface of the slip-ring. In severe conditions, it bursts out andbecomes the cause of accidents or explosions. 5.2 Life The life of the brush and the slip-ring are the main conditions for the motors normal operation.The life of the brush is decided
41、by its wear. The life of the slip-ring is also mutually related tothe physical characteristics of the brush. PD IEC/TR 63021:2016 8 IEC TR 63021:2016 IEC 2016 5.3 Temperature The proper temperature of the brush is a function of the brush current density, the coefficient offriction and the air flow i
42、n the area of the brush and slip-ring. 5.4 Dust diffusion The dust caused by the wear of the brush lowers the insulation resistance of the motor windingand contaminates the atmosphere around the motor. Dust diffusion can be characterized by thewear of brush. 5.5 Noise The rotor vibration can be cont
43、rolled with the vibration absorbing ability of the brush.The vibration absorbing ability is mutually related to the bulk density of brush. 6 Operating characteristics of natural graphite brush for slip-ring in a woundrotor-type induction motor 6.1 Current density Natural graphite brush for slip-ring
44、 in a wound rotor-type induction motor is three to four timeslighter than copper brush. Table 2 NG-brushs bulk density, electric resistivity and current densitycompared with the copper brush Property NG-brush Copper brush Bulk density, g/cm31,35 4,5 to 5,5 Electric resistivity, m 5 to15 0,05 to 3 Cu
45、rrent density, A/cm25 to 25 10 to 25 Table 2 shows that the electric resistivity of the NG-brush is 100 times higher than that of thecopper brush, but that the current density is nearly equal. 6.2 Vibration absorbing ability The higher the porosity and the lower the friction coefficient of the brush
46、, the more the vibrationcaused by the operation of the wound rotor-type induction motor decreases. See Table 3. Table 3 Comparison of properties for the assessment of vibration absorbing ability Property NG-brush Copper brush Porosity, % 43 1 to 2 Friction coefficient 0,12 2 Since the coefficient of
47、 friction of the NG-brush is 16 times lower than that of the copper brushand its porosity is 43 times higher than that of the copper brush, the NG-brush has the highervibration absorbing ability. 6.3 Temperature Permissible temperature of NG-brush during its operation is 80 . PD IEC/TR 63021:2016IEC
48、 TR 63021:2016 IEC 2016 9 6.4 Brushs pressure Copper brushs pressure is usually above 20 kPa to 40 kPa. NG-brush, however, hascharacteristics sufficient to operate in a range of 9 kPa to 10 kPa. 7 Testing method The test method on the physical properties and operating characteristics of NG-brush isp
49、erformed in accordance with IEC 60413 and IEC 60773. 8 Application result 8.1 Fire-spark Theres nearly no fire-spark between brush and slip-ring, because of the lighter weight andcurrent density of NG-brush. 8.2 Wear and life of brush Table 4 Wear and life of brush Brushs weight before testing (g) Brushs wear after testing (g) Life (year) Testing period(h) copper NG copper NG copper NG 288 64,8 22,5 0,6 0,8 10 1 000 Based on the consideration of
