1、Rotating electrical machinery Natural graphite brush for slip-ring in wound rotor-type induction motor Application information PD IEC/TR 63021:2016 BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National foreword This Published Document is the UK implementation of
2、IEC/TR 63021:2016. The UK participation in its preparation was entrusted to Technical Committee PEL/2, Rotating electrical machinery. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary prov
3、isions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 91409 6 ICS 29.160.01 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was
4、published under the authority of the Standards Policy and Strategy Committee on 30 September 2016. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TR 63021:2016IEC TR 63021 Edition 1.0 2016-09 TECHNICAL REPORT Rotating electrical machinery Natural graphite
5、 brush for slip-ring in wound rotor-type induction motor Application information INTERNATIONAL ELECTROTECHNICAL COMMISSION 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 authoriz
6、ed distributor. PD IEC/TR 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
7、 motor . . 7 5.1 Fire-spark 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 p
8、ressure . . 9 7 Testing method . 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 li
9、fe . 10 8.5.3 No accident due 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
10、Comparison of properties for 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 ELECTROTECHNIC
11、AL COMMISSION _ ROTATING ELECTRICAL 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 comprising all national electrotechnical comm
12、ittees (IEC National Committees). The object of IEC is to promote 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, Technica
13、l Reports, Publicly Available Specifications (PAS) and Guides (hereafter 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
14、 and non-governmental organizations liaising with the IEC also participate 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 agree
15、ments of IEC on technical matters express, as nearly as possible, 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 a
16、nd are accepted by IEC National Committees in that sense. While 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
17、 international uniformity, IEC National Committees undertake to 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 indicate
18、d in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) Al
19、l 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 individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage o
20、r 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 upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publicat
21、ion. 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 of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such
22、patent rights. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a Technical Report when it has collected data of a different kind from that which is normally published as an International Standard, for exam
23、ple “state of the art“. IEC TR 63021, which is a Technical 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 a
24、pproval of this Technical Report can be found in the report on 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 re
25、main unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the 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
26、 at a later date. PD IEC/TR 63021:2016IEC TR 63021:2016 IEC 2016 5 INTRODUCTION This Technical Report has been prepared after considering implications of the withdrawal of IEC PAS 62072:2005 and its potential conversion into an International Standard, and after analysing practical information obtain
27、ed through the application of natural graphite (NG) brush for 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 kinds of wound rotor-type induction motor are given in Annex A. PD IEC/T
28、R 63021:2016 6 IEC TR 63021:2016 IEC 2016 ROTATING ELECTRICAL 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 information on NG-brush for slip-ring o
29、btained through the application of NG-brush in various kinds of wound 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 for boring in oil or gas facility). 2 Normative
30、references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendme
31、nts) applies. IEC 60413, Test procedures for determining physical properties of brush materials for electrical machines IEC 60773, Test methods and apparatus for measurement of the operational characteristics of brushes 3 Terms and definitions For the purposes of this document, the following terms a
32、nd definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: 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 macrosc
33、opically between the brush and slip-ring during the operation of a wound rotor-type induction motor 3.2 life critical time since the brushes have been installed into the wound rotor-type induction motor and started to operate until the brush and the slip-ring can no longer contribute to the motors o
34、peration 3.3 dust diffusion phenomenon whereby fine powders, caused by wear of the brush, diffuse in air during the operation 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 amon
35、g the acoustic signals of several wavelengths made during the operation of a wound rotor-type induction motor 3.5 vibration absorbing ability ability of the brush to absorb or decrease electromagnetic and mechanical vibrations caused during the operation of a wound rotor-type induction motor 4 Gener
36、al remarks Generally, it is traditional to use the metal grade brush including copper brush for the wound rotor-type induction motor. The metal grade brush, including copper brushes, can usually damage the slip-ring by the fire-spark during operation. The dust generated by the wear of the copper bru
37、sh can be the cause of accidents and also contaminates the environment. Compared with the formerly used copper brush, the NG-brush shows high operating characteristics when it is used for the slip-ring of a wound rotor-type induction motor. There is nearly no fire-spark between the NG-brush and slip
38、-ring and no environmental pollution due to reduced wear. It also has sufficient ability of electromotion. Table 1 shows the size and quantity of typical NG-brushes that are used for wound rotor-type induction motors of various powers. Table 1 Typical kinds of brushes No. Denomination Size Quantity
39、(for a motor) Power mm kW 1 motor for elevator 253260 36 180 2 motor for compressor 253260 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
40、 brush and slip-ring for stability in the operation of a wound rotor-type induction motor 5.1 F ire-spark Fire-spark causes damage to the surface of the slip-ring. In severe conditions, it bursts out and becomes the cause of accidents or explosions. 5.2 Life The life of the brush and the slip-ring a
41、re the main conditions for the motors normal operation. The life of the brush is decided by its wear. The life of the slip-ring is also mutually related to the 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
42、 is a function of the brush current density, the coefficient of friction and the air flow in the area of the brush and slip-ring. 5.4 D ust diffusion The dust caused by the wear of the brush lowers the insulation resistance of the motor winding and contaminates the atmosphere around the motor. Dust
43、diffusion can be characterized by the wear of brush. 5.5 Noise The rotor vibration can be controlled 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-rin
44、g in a wound rotor-type induction motor 6.1 Current density Natural graphite brush for slip-ring in a wound rotor-type induction motor is three to four times lighter than copper brush. Table 2 NG-brushs bulk density, electric resistivity and current density compared with the copper brush Property NG
45、-brush Copper brush Bulk density, g/cm 31,35 4,5 to 5,5 Electric resistivity, m 5 to15 0,05 to 3 Current density, A/cm 25 to 25 10 to 25 Table 2 shows that the electric resistivity of the NG-brush is 100 times higher than that of the copper brush, but that the current density is nearly equal. 6.2 V
46、ibration absorbing ability The higher the porosity and the lower the friction coefficient of the brush, the more the vibration caused 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 Pr
47、operty NG-brush Copper brush Porosity, % 43 1 to 2 Friction coefficient 0,12 2 Since the coefficient of friction of the NG-brush is 16 times lower than that of the copper brush and its porosity is 43 times higher than that of the copper brush, the NG-brush has the higher vibration absorbing ability.
48、 6.3 T emperature Permissible temperature of NG-brush during its operation is 80 . PD IEC/TR 63021:2016IEC TR 63021:2016 IEC 2016 9 6.4 B rushs pressure Copper brushs pressure is usually above 20 kPa to 40 kPa. NG-brush, however, has characteristics sufficient to operate in a range of 9 kPa to 10 kP
49、a. 7 Testing method The test method on the physical properties and operating characteristics of NG-brush is performed in accordance with IEC 60413 and IEC 60773. 8 Application result 8.1 F ire-spark Theres nearly no fire-spark between brush and slip-ring, because of the lighter weight and current 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) Testi
