BS DD CLC TS 60034-24-2011 Rotating electrical machines Online detection and diagnosis of potential failures at the active parts of rotating electrical machines and of bearing curr.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationRotating electrical machinesPart 24: Online detection and diagnosis of potential failures at the active parts of rotating electrical machines and of bearing currents Application

2、guideDD CLC/TS 60034-24:2011National forewordThis Draft for Development is the UK implementation of CLC/TS 60034-24:2011. It is identical to IEC/TS 60034-24:2009.The UK participation in its preparation was entrusted to Technical Committee PEL/2, Rotating electrical machinery.A list of organizations

3、represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011ISBN 978 0 580 63063 7 ICS 29.160.01Compliance with a British Standard cannot

4、confer immunity from legal obligations.This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 31 July 2011.Amendments issued since publicationAmd. No. Date Text affectedDRAFT FOR DEVELOPMENTDD CLC/TS 60034-24:2011TECHNICAL SPECIFICATION CLC/TS

5、60034-24 SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION February 2011 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2011 CENELEC

6、- All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. CLC/TS 60034-24:2011 E ICS 29.160 English version Rotating electrical machines - Part 24: Online detection and diagnosis of potential failures at the active parts of rotating electrical machine

7、s and of bearing currents - Application guide (IEC/TS 60034-24:2009) Machines lectriques tournantes - Partie 24: Dtection et diagnostic en ligne de dfaillances potentielles des parties actives de machines lectriques tournantes et de courants de palier - Guide dapplication (CEI/TS 60034-24:2009) Dreh

8、ende elektrische Maschinen - Teil 24: Erkennung und Diagnose von mglichen Schden an den Aktivteilen drehender elektrischer Maschinen und von Lagerstrmen - Anwendungsleitfaden (IEC/TS 60034-24:2009) This Technical Specification was approved by CENELEC on 2011-01-25. CENELEC members are required to an

9、nounce the existence of this TS in the same way as for an EN and to make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria,

10、Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DD CLC/TS 60034-

11、24:2011CLC/TS 60034-24:2011 Foreword The text of the Technical Specification IEC/TS 60034-24:2009, prepared by IEC TC 2, Rotating machinery, was submitted to the formal vote and was approved by CENELEC as CLC/TS 60034-24 on 2011-01-25. Attention is drawn to the possibility that some of the elements

12、of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following date was fixed: latest date by which the existence of the CLC/TS has to be announced at national level (doa) 2011-07-25 _ Endorsement notic

13、e The text of the Technical Specification IEC/TS 60034-24:2009 was approved by CENELEC as a Technical Specification without any modification. DD CLC/TS 60034-24:2011DD CLC/TS 60034-24:2011DD CLC/TS 60034-24:2011 5 INTRODUCTION Progress in design and technology has resulted in an increasing reliabili

14、ty of rotating electrical machines, but failures could not be eliminated completely. Since the demand for a high availability is permanently increasing, it is essential to detect deficiencies at an early stage and to recognize the origin and identify the severity of the fault in order to estimate th

15、e risk of a continuation of operation. It would be advantageous, if the signals which are obtained by the detection methods presented in this guide, were suitable to distinguish the different failures from each other. By this means, the signal analysis can be used as input data of a complete monitor

16、ing system. The aim of this guide is to present possible tools which are available for the intended purpose and to explain their advantages and disadvantages. The minimum requirements which shall be met by the various sensors will be discussed, whereas the detailed design rules are outside the scope

17、 of this technical specification. This guide deals with the detection of failures at the active parts of multi-phase rotating machines (all kinds of winding faults in stator and rotor, cage deficiencies, eccentricities) and of bearing currents. DD CLC/TS 60034-24:2011 6 TS 60034-24 IEC:2009ROTATING

18、ELECTRICAL MACHINES Part 24: Online detection and diagnosis of potential failures at the active parts of rotating electrical machines and of bearing currents Application guide 1 Scope This part of IEC 60034 is applicable to the on-line detection and diagnosis of failures at the active parts of multi

19、-phase rotating electrical machines (induction and synchronous machines) and of bearing currents. The failure analysis includes: interturn faults; phase-to-phase short-circuits; double earth faults and single earth faults of motors with earth connection of the star-point; static and dynamic eccentri

20、cities; cage imperfection or defects (e.g. broken bars or end-rings); bearing currents. This can be achieved by tools like search coils or other magnetic sensors or partly by the analysis of the terminal voltages and currents. The detection of the following effects is excluded from the scope: vibrat

21、ion (covered by ISO standards, e.g. ISO 10816 and ISO 7919); partial discharge (covered by IEC 60034-27); single earth-faults of motors without earth connection of the star-point; core imperfection. Also excluded are special methods applicable for specific applications only (e.g. turbo generators).

22、2 Normative references There are no normative references in this technical specification. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 distribution factor the factor, related to a distributed winding, which takes into account the reduction

23、 in the generated voltage due to the phase difference between the voltages generated in the coils in different slots IEV 411-38-37 DD CLC/TS 60034-24:2011TS 60034-24 IEC:2009 7 3.2 chording (pitch) factor the factor, related to a distributed winding, which takes into account the reduction in the gen

24、erated voltage, when the winding pitch is not 100 % IEV 411-38-38 3.3 branch factor the factor, related to a distributed winding, which takes into account the reduction in the generated voltage due to the phase difference between the voltages generated in the series-connected branches 4 Basis of the

25、 diagnosis The ability of electrical machines to operate is based on the existence of a magnetic field in the air-gap, which is looping in a cross-sectional area of the laminations of stator and rotor. Flux components in the end-portions of the machine outside the cores are of a parasitic nature. Th

26、erefore available signals suitable for the detection of potential faults originate from the magnetic field in the air-gap, which shall be analyzed in order to distinguish between those components which occur under regular operating conditions and those components which are attributed to a specific f

27、ailure and which do not exist in a healthy machine. Since the winding producing the magnetic field consists of coils distributed symmetrically around the circumference and since the sum of the supplying currents is usually zero, the air-gap field forms also a periodic function along the circumferenc

28、e. The wave of the flux density can be considered as the superposition of a sum of sinusoidally distributed waves, which are characterized by the following features: amplitude, number of pole-pairs, angular velocity, phase-angle, type of wave (rotating or standing). Table 1 shows the composition of

29、the air-gap field in the case of a three-phase cage induction motor, which is equipped with an integral slot winding. The table can easily be extended to be valid also for fractional slot windings. Similar tables can be developed for slip-ring motors and all kinds of synchronous machines. DD CLC/TS

30、60034-24:2011 8 TS 60034-24 IEC:2009Table1Mostimportantmagneticfieldsintheair-gap ofathree-phasecageinductionmotorwith anintegralslotstatorwindingundernormaloperatingandfaultconditions OriginofthefieldStatorfields Rotor fields Itemwindingfields(slotharmonics) type:rotatingffrequency: 1numberofpole p

31、airs:1= p(1+6g1) g1= 0;1;2;.(slotharmonics:1 = p+g1Qs) type: rotatingfrequency: () +spQgf 11r21g2= 0;1;2;numberofpole pairs:2= 1+ g2Qr1 Fie l d s und e r no rma l op e r a t ing co n d i t i o n s saturationfields type:rotatingffrequency:31numberofpole pairs:1= 3ptype: rotatingfrequency: () +spQgf 1

32、3r 21g2= 0;1;2;numberofpole pairs:2= 3p+g2Qr2 Addi tio n a l f i e l d s und e r fa ul t c ond it ion s interturnfaultsphase-to-phasefaultsdoubleearthfaultstype: superposition ofreverse rotatingfieldsof differentamplitudeffrequency: 1numberofpole pairs:1= 1;2;3;.type: superposition ofreverse rotatin

33、gfieldsof differentamplitudefrequency: () +spQgf 11r21g2= 1;2;+positive-sequencefieldsnegative-sequencefieldsnumberofpole pairs:2= 1+ g2Qr3 DD CLC/TS 60034-24:2011TS 60034-24 IEC:2009 9 OriginofthefieldStatorfields Rotor fields Itemeccentricitytype: 2rotatingfieldsffrequency: 11pK(1s) K=0:staticecce

34、ntricityK=1:dynamiceccentricitynumberofpole pairs:1 = p1type: 2rotatingfieldsfrequency: () +spQgpKf 11r 21numberofpole pairs:2= 1+ g2Qrg2= 0;1;2;4 rotorasymmetrytype: superpositionof reverserotatingfieldsof thesameamplitudefrequency: ()+spsf121numberofpole pairs:2= 1;2;3;5 Symbols: f1fundamental fre

35、quencyQsnumberofstatorslotsp numberofpolepairs,Qrnumberofrotorbarsforwhich themotorisdesigned s slipnumberofpole pairsingeneral DD CLC/TS 60034-24:2011 10 TS 60034-24 IEC:20095 Kinds of electrical signal analysis 5.1 General A valuable detection method shall be able to detect failures at an early st

36、age. Therefore signals disclosing a rapid change in the case of small deficiencies, are optimal for the intended purpose. By contrast signals which vary only insignificantly should not be used as the basis of the diagnosis. The signal processing needs the availability of appropriate electronic equip

37、ment. Although the resolution of modern devices is high, signals which do not need excessive precision should be preferred in this respect. 5.2 Stator current/voltage analysis The analysis of the terminal voltages or currents of a rotating machine allows identification of different frequencies, posi

38、tive-, negative-, and zero-sequence components, different amplitudes of the components. In general, all waves of induction in the air-gap field can induce voltages of certain frequencies in the stator winding and can cause currents of the same frequencies. The additional current components which are

39、 generated by a specific failure are superimposed to the supply values during undisturbed operation. All details shall be taken from the relevant table, that is Table 1 in the case of three-phase cage induction motors. Table 1 is worded for one single supply frequency f1. However, in case of a conve

40、rter supplied machine, it is valid for each voltage/frequency component, which is contained in the output spectrum of the converter. Table 1 shows the components of the air-gap field. Whether a specific component induces a voltage in the stator winding, depends on its winding factor for the number o

41、f pole pairs under consideration. The winding factor is the product of the following terms: the distribution factor, the chording factor, the branch factor. The branch factor is not generally known amongst engineers, but of fundamental importance for the problem under consideration. Each symmetrical

42、 three-phase integral slot winding consists of p (in case of a single-layer winding) or 2p (in case of a double-layer winding) identical coil groups (branches), which are distributed symmetrically around the circumference. They can be series-connected or connected to form parallel branches with the

43、maximum number a = 2p. The connecting method considerably influences the branch factor of a specific number of pole pairs. It can be shown that the branch factor is zero for the eccentricity fields = p + 1 and = p 1 for all windings with series-connection of the coil-groups. Consequently both types

44、of eccentricity cannot be detected for such machines by stator current analysis. The branch factor of the harmonic fields according to item 1 to 4 of Table 1 depends also on the individual configuration and in addition on the number of rotor slots. The design of a given case is selected by the manuf

45、acturer of the machine for different reasons (e.g. to suppress unbalanced magnetic pull, to avoid nasty magnetic tones, etc.) and unknown to the user. It is therefore not advisable to use the harmonic rotor fields of items 3 and 4 as the signal for a stator current analysis. DD CLC/TS 60034-24:2011T

46、S 60034-24 IEC:2009 11 The group of winding faults in item 3 marks the most severe deficiencies at the active parts. They all produce magnetic fields of fundamental frequency. Thus winding faults cannot be detected by a frequency analysis of the stator currents. The field waves, produced by winding

47、faults, are of elliptic nature, which means the superposition of two reverse rotating waves, having the same number of poles and the same frequency, but different amplitudes. In principle such failures can be detected by exploring the negative sequence component of the current of fundamental frequen

48、cy. Especially in case of the most dangerous failure, an interturn fault of a high-voltage machine, when the high currents flow in only one of many turns per phase, this component is very small. A negative-sequence component of the current may also be caused by an unavoidable small asymmetry of the

49、supply voltages (a negative sequence component of the voltage results in a negative sequence component of the currents, which is 6 to 10-times higher). Summing up, it is not recommendable to detect winding faults by means of a voltage/current analysis. Reliable detection of cage imperfection or defects (e.g. bro