1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58fed from converters Application guideICS 29.160Rotating electrical machines Part 17: Cage induction
2、 motors when DRAFT FOR DEVELOPMENTDD IEC/TS 60034-17:2006DD IEC/TS 60034-17:2006This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 BSI 2006ISBN 0 580 48663 Xcomments will be welcomed. These should be sent to the Secretary of BS
3、I Technical Committee PEL/2, Rotating electrical machines, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text.A list of organizations represented on this committee can b
4、e obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facil
5、ity of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Summary of pagesThis document comprises a front cover, an inside front cover, the IEC/TS title
6、 page, pages 2 to 19 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA review of this Draft for Development will be carried out not later than 2 years after its publication.Notif
7、ication of the start of the review period, with a request for the submission of comments from users of this Draft for Development, will be made in an announcement in the appropriate issue of Update Standards. According to the replies received, the responsible BSI Committee will judge whether the Dra
8、ft for Development can be converted into a British Standard or what other action should be taken.Observations which it is felt should receive attention before the official call for National forewordThis Draft for Development reproduces verbatim IEC/TS 60034-17:2006. It supersedes DD IEC/TS 60034-17:
9、2002 which is withdrawn.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so that information and experience of its practical application
10、can be obtained.IECTECHNICAL SPECIFICATION TS 60034-17Fourth edition2006-05Rotating electrical machines Part 17: Cage induction motors when fed from converters Application guide Reference number CEI/IEC/TS 60034-17:2006 DD IEC/TS 60034-17:2006CONTENTS INTRODUCTION.31 Scope.4 2 Normative references4
11、3 Characteristics of the motor 4 4 Frequency spectrum of voltage and/or currents .5 5 Losses caused by harmonics 7 6 Torque derating during converter operation .10 7 Oscillating torques 11 8 Magnetically excited noise 12 9 Service life of the insulation system 13 10 Bearing currents .15 11 Installat
12、ion (cabling, grounding, bonding) 18 12 Maximum safe operating speed.18 13 Power factor correction.19 Figure 1 Waveform of phase current iphasein delta connection for current source converter supply (idealized example).5 Figure 2 Waveform of line-to-line voltage uLLfor voltage source converter suppl
13、y with switching frequency fs= 30 f1(example) 6 Figure 3 Example for the dependence of the motor losses caused by harmonics Ph, related to the losses Pf1at operating frequency f1, on the switching frequency fsin case of voltage source converter supply 7 Figure 4 Influence of converter supply on the
14、losses of a cage induction motor (frame size 315 M, design N) with rated values of torque and speed 9 Figure 5 Fundamental voltage U1as a function of operating frequency f110 Figure 6 Torque derating factor for cage induction motors of design N, IC 0141 (self-circulating cooling) for current source
15、converter supply as a function of operating frequency f1(example)11 Figure 7 Limiting curve of admissible impulse voltage LL(including voltage reflection and damping) at the motor terminals as a function of the rise time tr14 Figure 8 Definition of the peak rise time trof the voltage at the motor te
16、rminals14 Figure 9 Ring flux including shaft voltage and resulting circulating current icirc.15 Figure 10 Common mode circuit model and bearing voltage ubrg.17 2 DD IEC/TS 60034-17DD IEC/TS 60034-17:2006INTRODUCTION The performance characteristics and operating data for drives with converter-fed cag
17、e induc-tion motors are influenced by the complete drive system, comprising supply system, converter, induction motor, mechanical shafting and control equipment. Each of these components exists in numerous technical variations. Any values quoted in this technical specification are thus indicative on
18、ly. In view of the complex technical interrelations within the system and the variety of operating conditions, it is beyond the scope and object of this technical specification to specify numerical or limiting values for all the quantities which are of importance for the design of the drive. To an i
19、ncreasing extent, it is practice that drives consist of components produced by different manufacturers. The object of this technical specification is to explain and quantify, as far as possible, the criteria for the selection of components and their influence on the performance characteristics of th
20、e drive. The technical specification deals with motors within the scope of IEC 60034-12, i.e. low-voltage series-fabricated three-phase cage induction motors, which are designed originally for mains supply, covering the design N or design H requirements. Motors which are specifically designed for co
21、nverter supply are covered by IEC 60034-25. 3 DD IEC/TS 60034-17:2006ROTATING ELECTRICAL MACHINES Part 17: Cage induction motors when fed from converters Application guide 1 Scope This technical specification deals with the steady-state operation of cage induction motors within the scope of IEC 6003
22、4-12, when fed from converters. It covers the operation over the whole speed setting range, but does not deal with starting or transient phenomena. Only indirect type converters are dealt with. This type comprises converters with impressed direct current in the intermediate circuit (current source c
23、onverters) and converters with impressed d.c. voltage (voltage source converters), either of the block type or the pulse controlled type, without restriction on pulse number, pulse width or switching frequency. For the purposes of this technical specification, a converter may include any type of ele
24、ctronic switching device, for example transistors (bipolar or MOSfet), IGBTs, thyristors, GTO-thyristors, etc. with analog or digital control electronics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the
25、edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60034-1, Rotating electrical machines Part 1: Rating and performance IEC 60034-12, Rotating electrical machines Part 12: Starting performance of single-speed three-pha
26、se cage induction motors IEC 60034-25, Rotating electrical machines Part 25: Guide for the design and performance of cage induction motors specifically designed for converter supply 3 Characteristics of the motor The output current of a current source converter passes through the stator winding of t
27、he motor during the commutating period. Therefore, a knowledge of the motor equivalent circuit is important for the design of the commutating circuits. In the case of voltage source converters, a knowledge of the motor equivalent circuit is normally not important for the design of the commutating ci
28、rcuit, but the harmonic impedances of the motor greatly influence the losses caused by harmonics. 4 DD IEC/TS 60034-17DD IEC/TS 60034-17:2006The above conditions are relevant for the basic operation capability of the drive. If details are required of the additional torques (in particular oscillating
29、 torques) and of the additional losses, which occur during converter operation, then a knowledge of the equivalent circuit parameters of the motor covering the harmonic spectrum will be necessary. Due to the existing design variants of cage induction motors with design N (e.g. copper deep-bar rotors
30、 and aluminium double-cage rotors are used) and due to the wide frequency range of the most important harmonics (band width from 0 kHz up to 30 kHz), a generally valid motor equivalent circuit cannot be specified. As a rule, it is not admissible to use the quantities from the equivalent circuit for
31、steady-state operation at power frequency (e.g. with leakage inductances for normal running) in order to calculate torques and losses due to harmonics. The motor manufacturer may provide appropriate values of the equivalent circuit only if the frequency spectrum of currents and/or voltages generated
32、 by the converter is known. 4 Frequency spectrum of voltage and/or currents With respect to the necessary torque derating and to the oscillating torques excited by harmonics, it is important to know the frequency spectra of motor voltages (in case of voltage source converters) or motor currents (in
33、case of current source converters). Figure 1 shows the typical waveform of the motor phase current in the case of a current source converter drive. The produced harmonics are of the order n = 5; 7; 11; 13. The relative harmonic content is influenced by the commutating time interval which may differ
34、in different drives. t iphase60 120 240 300 180 360 IEC 784/06 Figure 1 Waveform of phase current iphasein delta connection for current source converter supply (idealized example) 5 DD IEC/TS 60034-17:2006Figure 2 shows the typical waveform of the motor line-to-line voltage for operation with a volt
35、age source converter with pulse width modulation (PWM converter). t uLL 60 120 240 300 360 180 IEC 785/06 Figure 2 Waveform of line-to-line voltage uLLfor voltage source converter supply with switching frequency fs= 30 f1(example) In the case of voltage source converters a variety of modulation type
36、s is in use. Hence it is not possible to make global statements on the effects of the harmonics. For definite statements, the harmonic content of the converter output voltage must be known and its consequences on the motor shall be studied. Converters using carrier modulation, together with synchron
37、ised and asynchronous pulse patterns, as applied in many cases, produce the frequencies: 11ssfkfkf = where ks= 1, 2, 3,. and k1= 1, 2, 4, 5, 7. are multiplying factors of the switching frequency fsand of the operating frequency f1, respectively. The formula is valid also in the case of converters wi
38、th space-phasor modulation. Converters with carrierless modulation, where no pre-determined switching frequency is existent, are also in practical use. In this case, the frequency spectrum of the output voltage is characterised by broadband random noise without spikes at specific frequencies. With p
39、ulse controlled converters, the content of harmonics with low frequencies can be kept low, while the dominant harmonics (which are near the switching frequency) will occur at relatively large frequency values, not having much effect due to the motor winding inductances. In 7.2.1 of IEC 60034-1 the p
40、ermissible harmonic content of the supply voltage of cage induction motors is expressed by one single numerical value called the harmonic voltage factor (HVF). However, this factor is not applicable for converter power supplies. 6 DD IEC/TS 60034-17DD IEC/TS 60034-17:20065 Losses caused by harmonics
41、 Harmonics of voltage and current in a cage induction motor supplied from a converter cause additional iron and winding losses in the stator and the rotor. In the case of motors supplied by voltage source converters, the additional iron losses cannot be neglected. They depend on the amplitudes of th
42、e phase voltage harmonics, but they are nearly independent on its frequency. The harmonic currents, which are responsible for the winding losses, are limited by the leakage reactances. Although the harmonic currents are small, the winding losses cannot be ignored because of the current displacement
43、(skin effect) due to the high frequencies. This statement applies to both form-wound and random-wound windings. Rotors with pronounced current displacement (skin effect) are especially sensitive to these losses. It is verified by many tests, that the total value of the additional losses caused by ha
44、rmonics does not depend on load; they decrease with increasing switching frequency (see Figure 3). This effect is caused by the small additional winding losses at high switching frequencies. 0 0 1 2 3 4 5 6 7 8 9 10 11 fskHzPh0,1 0,2 0,3 0,4 Pf1123 IEC 786/06 1 = Total harmonic losses 2 = Harmonic w
45、inding losses 3 = Harmonic iron losses Figure 3 Example for the dependence of the motor losses caused by harmonics Ph, related to the losses Pf1at operating frequency f1, on the switching frequency fsin case of voltage source converter supply 7 DD IEC/TS 60034-17:2006In the case of motors supplied b
46、y current-source converters, the additional iron losses are nearly negligible with the exception of the so-called commutation losses. The fast change of the leakage fluxes during the commutation interval generates eddy currents in the teeth of stator and rotor. There are no commutation losses in the
47、 case of operation from voltage source converters because the commutation currents do not flow through the motor windings. The additional rotor winding losses play an important role due to the relative high amplitudes of the harmonic currents of low frequency. There is no simple method to calculate
48、the additional losses, and no general statement can be made about their value. Their dependence upon the different physical quantities is very complex. Also, there is a great variety both of converters (e.g. current and voltage source converters with different switching frequencies and pulse pattern
49、s) and of motors (e.g. kind of winding, slot geometry, specific iron loss). The quality of core manufacture is also an important feature. The columns in Figure 4 show, as an example, the calculated loss composition of a specific motor (frame size 315 M; design N) when supplied both from different converters with different harmonic content and from a sinusoidal supply. The example illustrates the relative importance of the different types of losses for the converter syst
