IEC TS 60034-25:2007

TECHNICAL IEC
SPECIFICATION TS 60034-25
Second edition
2007-03
Rotating electrical machines –
Part 25:
Guidance for the design and performance of a.c.
motors specifically designed for converter supply
Reference number
IEC/TS 60034-25:2007(E)
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TECHNICAL IEC
SPECIFICATION TS 60034-25
Second edition
2007-03
Rotating electrical machines –
Part 25:
Guidance for the design and performance of a.c.
motors specifically designed for converter supply
© IEC 2007 ⎯ 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.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
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– 2 – TS 60034-25 © IEC:2007(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.9
2 Normative references .9
3 Terms and definitions .10
4 System characteristics.11
4.1 General .11
4.2 System information.11
4.3 Torque/speed considerations.12
4.4 Motor requirements .16
5 Losses and their effects (for induction motors fed from U-converters).18
5.1 General .18
5.2 Location of the additional losses due to converter supply and ways to
reduce them .18
5.3 Converter features to reduce the motor losses .18
5.4 Use of filters to reduce additional motor losses due to converter supply .20
5.5 Temperature and life expectancy.20
5.6 Determination of motor efficiency .21
6 Noise, vibration and torsional oscillation.21
6.1 Noise .21
6.2 Vibration (excluding torsional oscillation).24
6.3 Torsional oscillation .25
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 .31
7.8 Motor choice .31
8 Bearing currents .32
8.1 Sources of bearing currents in converter-fed motors.32
8.2 Generation of high-frequency bearing currents .32
8.3 Common mode circuit.34
8.4 Stray capacitances .34
8.5 Consequences of excessive bearing currents .36
8.6 Preventing high-frequency bearing current damage.36
8.7 Additional considerations for motors fed by high voltage U-converters .38
8.8 Bearing current protection for motors fed by high-voltage current-source
converters (I-converters) .39
9 Installation.39
9.1 Earthing, bonding and cabling .39
9.2 Reactors and filters .45
9.3 Integral motors (integrated motor and drive modules).46

TS 60034-25 © IEC:2007(E) – 3 –
10 Additional considerations for permanent magnet (PM) synchronous motors fed by
U-converters.47
10.1 System characteristics .47
10.2 Losses and their effects .47
10.3 Noise, vibration and torsional oscillation.47
10.4 Motor insulation electrical stresses.47
10.5 Bearing currents.48
10.6 Particular aspects of permanent magnets .48
11 Additional considerations for cage induction motors fed by high voltage U-
converters .48
11.1 General .48
11.2 System characteristics .48
11.3 Losses and their effects .50
11.4 Noise, vibration and torsional oscillation.50
11.5 Motor insulation electrical stresses.51
11.6 Bearing currents.53
12 Additional considerations for synchronous motors fed U-converters.53
12.1 System characteristics .53
12.2 Losses and their effects .53
12.3 Noise, vibration and torsional oscillation.53
12.4 Motor insulation electrical stresses.53
12.5 Bearing currents.53
13 Additional considerations for cage induction motors fed by block-type I-converters .54
13.1 System characteristics .54
13.2 Losses and their effects .55
13.3 Noise, vibration and torsional oscillation.55
13.4 Motor insulation electrical stresses.56
13.5 Bearing currents.56
13.6 Additional considerations for six-phase cage induction motors .56
14 Additional considerations for synchronous motors fed by LCI .56
14.1 System characteristics .56
14.2 Losses and their effects .58
14.3 Noise, vibration and torsional oscillation.58
14.4 Motor insulation electrical stresses.58
14.5 Bearing currents.58
15 Additional considerations for pulsed I-converters (PWM CSI) feeding induction
motors .58
15.1 System characteristics .58
15.2 Losses and their effects .59
15.3 Noise, vibration and torsional oscillation.59
15.4 Motor insulation electrical stresses.59
15.5 Bearing currents.59
16 Other motor/converter systems.60
16.1 Drives supplied by cyclo-converters .60
16.2 Wound rotor induction (asynchronous) machines supplied by I-converters in
the rotor circuit .61
16.3 Wound rotor induction (asynchronous) machines supplied by U-converters in
the rotor circuit .61

– 4 – TS 60034-25 © IEC:2007(E)
Annex A (normative) Converter characteristics .63
Annex B (informative) Converter output spectra.67
Annex C (informative) Noise increments due to converter supply .70
Bibliography.71
Figure 1 – Torque/speed capability .13
Figure 2 – Converter output current .13
Figure 3 – Converter output voltage/frequency characteristics .15
Figure 4 – Example of measured
...