IEC TS 60034-25:2004

TECHNICAL IEC
SPECIFICATION TS 60034-25
First edition
2004-04
Rotating electrical machines –
Part 25:
Guide for the design and performance
of cage induction motors specifically designed
for converter supply
Reference number
IEC/TS 60034-25:2004(E)
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TECHNICAL IEC
SPECIFICATION TS 60034-25
First edition
2004-04
Rotating electrical machines –
Part 25:
Guide for the design and performance
of cage induction motors specifically designed
for converter supply
 IEC 2004  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale X

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – TS 60034-25  IEC:2004(E)

CONTENTS
FOREWORD.5

INTRODUCTION.7

1 Scope.8

2 Normative references .8

3 Terms and definitions .9

4 System characteristics.10

4.1 General .10
4.2 System information.10
4.3 Torque/speed considerations.10
4.3.1 General .10
4.3.2 Torque/speed capability.11
4.3.3 Voltage/speed characteristics .12
4.3.4 Limiting factors on torque/speed capability .12
4.3.5 Resonant speed bands .13
4.3.6 Duty cycles.13
4.4 Converter control types .13
4.4.1 General .13
4.4.2 Converter type considerations .14
4.5 Converter output voltage generation.15
4.5.1 Pulse Width Modulation (PWM) .15
4.5.2 Hysteresis (sliding mode) .15
4.5.3 Influence of switching frequency.16
4.5.4 Multi-level converters .17
4.6 Motor requirements .17
5 Losses and their effects.19
5.1 General .19
5.2 Losses in motors supplied from voltage-source converters .19
5.3 Location of the extra losses and ways to reduce them .20
5.4 Converter features to reduce the motor losses .20
5.5 Temperature and life expectancy.21
5.6 Determination of motor efficiency .21

6 Noise, vibration and oscillating torques .21
6.1 Noise and vibration in an induction motor supplied from a converter.21
6.1.1 General .21
6.1.2 Changes in noise emission due to changes in speed .22
6.1.3 Magnetically excited noise.23
6.1.4 Torsional oscillation.23
6.2 Sound power level determination and limits .24
6.2.1 Methods of measurement .24
6.2.2 Test conditions .24
6.2.3 Sound power level limits.24
6.3 Vibration level determination and limits .24
6.3.1 Method of measurement .24
6.3.2 Test conditions .25
6.3.3 Vibration level limits .25

TS 60034-25  IEC:2004(E) – 3 –

7 Motor insulation electrical stresses .25

7.1 General .25

7.2 Causes.25

7.3 Winding electrical stress.27

7.4 Insulation stress limitation .29

7.5 Responsibilities .29

7.6 Converter characteristics.30

7.7 Methods of reduction of voltage stress .30

7.8 Motor choice .31

8 Bearing currents .31
8.1 Sources of bearing currents in converter-fed motors.31
8.1.1 General .31
8.1.2 Magnetic asymmetry.31
8.1.3 Electrostatic buildup .32
8.1.4 High frequency voltages .32
8.2 Generation of high frequency bearing currents .32
8.2.1 General .32
8.2.2 Circulating current .33
8.2.3 Shaft grounding current .33
8.2.4 Capacitive discharge current .33
8.3 Common-mode circuit.33
8.3.1 General .33
8.3.2 System common-mode current flow .33
8.4 Stray capacitances .34
8.4.1 General .34
8.4.2 Major component of capacitance .34
8.4.3 Other capacitances.35
8.5 Consequences of excessive bearing currents .35
8.6 Preventing high frequency bearing current damage .36
8.6.1 Basic approaches .36
8.6.2 Other preventive measures.36
9 Installation.38
9.1 Grounding, bonding and cabling .38
9.1.1 General .38
9.1.2 Grounding .38

9.1.3 Bonding of motors .39
9.1.4 Motor power cables .39
9.2 Reactors and filters .44
9.2.1 General .44
9.2.2 Output reactors.44
9.2.3 Voltage limiting filter (dv/dt filter) .44
9.2.4 Sinusoidal filter.44
9.2.5 Motor termination unit.44

Annex A (informative) Converter output spectra.46

Bibliography.48

– 4 – TS 60034-25  IEC:2004(E)

Figure 1 – Component parts of a PDS.7

Figure 2 – Torque/speed capability .11

Figure 3 – Converter output current .11

Figure 4 – Converter output voltage .12

Figure 5 – Effects of switching frequency on motor and converter losses .16

Figure 6 – Effects of switching frequency on acoustic noise.16

Figure 7 – Effects of switching frequency on torque ripple .17

Figure 8 – Example of measured losses W, as a function of frequency f and suppl
...