SIST-TS CLC IEC/TS 60034-25:2024

SLOVENSKI STANDARD
01-oktober-2024
Električni rotacijski stroji - 25. del: Smernice za konstrukcijo in karakteristike
asinhronskih motorjev s kratkostično kletko, posebej narejenih za napajanje s
pretvornikom (IEC/TS 60034-25:2022)
Rotating electrical machines - Part 25: AC electrical machines used in power drive
systems - Application guide (IEC/TS 60034-25:2022)
Drehende elektrische Maschinen - Teil 25: Wechselstrommaschinen zur Verwendung in
Antriebssystemen - Anwendungsleitfaden (IEC/TS 60034-25:2022)
Machines électriques tournantes - Partie 25: Machines électriques à courant alternatif
utilisées dans les systèmes d'entraînement de puissance - Guide d'application(IEC/TS
60034-25:2022)
Ta slovenski standard je istoveten z: CLC IEC/TS 60034-25:2024
ICS:
29.160.01 Rotacijski stroji na splošno Rotating machinery in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION CLC IEC/TS 60034-25

SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION February 2024
ICS 29.160.01 Supersedes CLC/TS 60034-17:2004; CLC/TS 60034-
25:2008
English Version
Rotating electrical machines - Part 25: AC electrical machines
used in power drive systems - Application guide
(IEC/TS 60034-25:2022)
Machines électriques tournantes - Partie 25: Machines Drehende elektrische Maschinen - Teil 25:
électriques à courant alternatif utilisées dans les systèmes Wechselstrommaschinen zur Verwendung in
d'entraînement de puissance - Guide d'application Antriebssystemen - Anwendungsleitfaden
(IEC/TS 60034-25:2022) (IEC/TS 60034-25:2022)
This Technical Specification was approved by CENELEC on 2024-01-22.

CENELEC members are required to announce 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, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC IEC/TS 60034-25:2024 E

European foreword
This document (CLC IEC/TS 60034-25:2024) consists of the text of IEC/TS 60034-25:2022 prepared by
IEC/TC 2 "Rotating machinery".
This document supersedes CLC/TS 60034-17:2004 and CLC/TS 60034-25:2008 and all of their
amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Technical Specification IEC/TS 60034-25:2022 was approved by CENELEC
as a European Technical Specification without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 61800-2:2021 NOTE Approved as EN IEC 61800-2:2021 (not modified)
IEC/TR 61800-6 NOTE Approved as CLC/TR 61800-6
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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 amendments) applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60034-1 2022 Rotating electrical machines - Part 1: Rating EN IEC 60034-1 —
and performance
IEC 60034-2-1 - Rotating electrical machines - Part 2-1: EN 60034-2-1 -
Standard methods for determining losses
and efficiency from tests (excluding
machines for traction vehicles)
IEC 60034-2-2 - Rotating electrical machines - Part 2-2: EN 60034-2-2 -
Specific methods for determining separate
losses of large machines from tests -
Supplement to IEC 60034-2-1
IEC 60034-2-3 - Rotating electrical machines - Part 2-3: EN IEC 60034-2-3 -
Specific test methods for determining
losses and efficiency of converter-fed AC
motors
IEC 60034-6 - Rotating electrical machines - Part 6: EN 60034-6 -
Methods of cooling (IC Code)
IEC 60034-9 2021 Rotating electrical machines - Part 9: Noise EN IEC 60034-9 —
limits
IEC 60034-12 - Rotating electrical machines - Part 12: EN 60034-12 -
Starting performance of single-speed three-
phase cage induction motors
IEC 60034-14 2018 Rotating electrical machines - Part 14:
EN IEC 60034-14 2018
Mechanical vibration of certain machines
with shaft heights 56 mm and higher -
Measurement, evaluation and limits of
vibration severity
To be published. Stage at the time of publication: FprEN IEC 60034-1:2021.
To be published. Stage at the time of publication: FprEN IEC 60034-9:2021.
Publication Year Title EN/HD Year
Rotating electrical machines - Part 18-41:
IEC 60034-18-41 2014 EN 60034-18-41 2014
Partial discharge free electrical insulation
systems (Type I) used in rotating electrical
machines fed from voltage converters -
Qualification and quality control tests
+ A1 2019 + A1 2019
Rotating electrical machines - Part 18-42:
IEC 60034-18-42 2017 EN 60034-18-42 2017
Partial discharge resistant electrical
insulation systems (Type II) used in rotating
electrical machines fed from voltage
converters - Qualification tests
+ A1 2020 + A1 2020
IEC 60079 series Explosive atmospheres EN IEC 60079 series
IEC 60079-7 - Explosive atmospheres - Part 7: Equipment EN 60079-7 -
protection by increased safety "e"
IEC/TR 61000-5-1 - Electromagnetic compatibility (EMC) - Part - -
5: Installation and mitigation guidelines -
Section 1: General considerations - Basic
EMC publication
IEC/TR 61000-5-2 - Electromagnetic compatibility (EMC) - Part - -
5: Installation and mitigation guidelines -
Section 2: Earthing and cabling
IEC 61800-3 - Adjustable speed electrical power drive EN IEC 61800-3 -
systems - Part 3: EMC requirements and
specific test methods for PDS and machine
tools
IEC 61800-5-1 - Adjustable speed electrical power drive
EN IEC 61800-5-1 -
systems - Part 5-1: Safety requirements -
Electrical, thermal and energy
IEC/TS 61800-8 2010 Adjustable speed electrical power drive - -
systems - Part 8: Specification of voltage on
the power interface
IEC/TS 62578 2015 Power electronics systems and equipment -
- -
Operation conditions and characteristics of
active infeed converter (AIC) applications
including design recommendations for their
emission values below 150 kHz
IEC TS 60034-25 ®
Edition 4.0 2022-06
TECHNICAL
SPECIFICATION
colour
inside
Rotating electrical machines –

Part 25: AC electrical machines used in power drive systems – Application guide

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.160.01 ISBN 978-2-8322-2003-0

– 2 – IEC TS 60034-25:2022 © IEC 2022
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms and definitions . 13
4 System characteristics . 16
4.1 General . 16
4.2 System information . 16
4.3 Torque/speed considerations . 16
4.3.1 General . 16
4.3.2 Torque/speed capability . 17
4.3.3 Electrical machine rating. 18
4.3.4 Limiting factors on torque/speed capability . 18
4.3.5 Safe operating speed, over-speed capability and over-speed test . 19
4.3.6 Cooling arrangement . 19
4.3.7 Voltage/frequency characteristics . 20
4.3.8 Resonant speed bands . 20
4.3.9 Duty cycles . 21
4.4 Electrical machine requirements . 21
5 Losses and their effects (for induction electrical machines fed from voltage source
converters) . 24
5.1 General . 24
5.2 Location of the additional losses due to converter supply and ways to reduce
them . 25
5.3 Converter features to reduce the electrical machine losses . 26
5.3.1 Reduction of fundamental losses . 26
5.3.2 Reduction of additional losses due to converter supply . 26
5.4 Use of filters to reduce additional electrical machine losses due to converter
supply . 27
5.5 Temperature influence on life expectancy . 27
5.6 Determination of electrical machine efficiency . 28
6 Acoustic noise, vibration and torsional oscillation . 28
6.1 Acoustic noise . 28
6.1.1 General . 28
6.1.2 Changes in noise emission due to changes in speed . 28
6.1.3 Magnetically excited noise . 29
6.1.4 Sound power level determination and limits . 31
6.2 Vibration (excluding torsional oscillation) . 31
6.2.1 General . 31
6.2.2 Vibration level determination and limits . 32
6.3 Torsional oscillation . 32
7 Electrical machine insulation electrical stresses . 33
7.1 General . 33
7.2 Causes . 33
7.3 Winding electrical stress . 35
7.4 Limits and responsibility . 36

IEC TS 60034-25:2022 © IEC 2022 – 3 –
7.4.1 Electrical machines design for low voltage (≤ 1 000 V) . 36
7.4.2 Electrical machines designed for medium and high voltage (> 1 000 V) . 37
7.5 Methods of reduction of voltage stress . 37
7.6 Insulation stress limitation . 38
8 Bearing currents . 39
8.1 Sources of bearing currents in converter-fed electrical motors . 39
8.1.1 General . 39
8.1.2 Circulating currents due to magnetic asymmetry . 39
8.1.3 Electrostatic build-up . 39
8.1.4 High-frequency effects in converter operation . 39
8.2 Generation of high-frequency bearing currents . 41
8.2.1 Common mode voltage . 41
8.2.2 Motor HF equivalent circuit and the resulting bearing current types . 42
8.2.3 Circulating current . 44
8.2.4 Rotor ground current . 44
8.2.5 Electrostatic Discharge Machining (EDM) currents . 45
8.3 Consequences of excessive bearing currents. 46
8.4 Preventing high-frequency bearing current damage . 50
8.4.1 Basic approaches . 50
8.4.2 Other preventive measures . 51
8.4.3 Other factors and features influencing the bearing currents . 54
8.5 Additional considerations for electrical motors fed by high voltage source
converters . 54
8.5.1 General . 54
8.5.2 Bearing protection of cage induction, brushless synchronous and
permanent magnet electrical motors . 54
8.5.3 Bearing protection for slip-ring electrical motors and for synchronous

electrical motors with brush excitation . 54
8.6 Bearing current protection for electrical motors fed by high-voltage current
source converters . 55
9 Installation . 55
9.1 Earthing, bonding and cabling . 55
9.1.1 General . 55
9.1.2 Earthing . 55
9.1.3 Bonding of electrical machines . 55
9.1.4 Electrical machine power cables for high switching frequency
converters . 56
9.2 Reactors and filters . 61
9.2.1 General . 61
9.2.2 Output reactors . 61
9.2.3 Voltage limiting filter (du/dt filter) . 61
9.2.4 Sinusoidal filter . 61
9.2.5 Electrical machine termination unit . 61
9.3 Power factor correction . 62
9.4 Integral electrical machines (integrated electrical machine and drive
modules) . 63
10 Additional considerations for permanent magnet (PM) synchronous electrical
machines fed by voltage source converters . 63
10.1 System characteristics . 63
10.2 Losses and their effects . 63

– 4 – IEC TS 60034-25:2022 © IEC 2022
10.3 Noise, vibration and torsional oscillation . 64
10.4 Electrical machine insulation electrical stresses . 64
10.5 Bearing currents . 64
10.6 Particular aspects of permanent magnets . 64
11 Additional considerations for cage induction electrical machines fed by high

voltage source converters . 64
11.1 General . 64
11.2 System characteristics . 65
11.3 Losses and their effects . 66
11.3.1 Additional losses in the stator and rotor winding . 66
11.3.2 Measurement of additional losses . 66
11.4 Noise, vibration and torsional oscillation . 66
11.5 Electrical machine insulation electrical stresses . 67
11.5.1 General . 67
11.5.2 Electrical machine terminal overvoltage . 67
11.5.3 Stator winding voltage stresses in converter applications. 67
11.6 Bearing currents . 69
12 Additional considerations for synchronous electrical machines fed by voltage
source converters . 69
12.1 System characteristics . 69
12.2 Losses and their effects . 69
12.3 Noise, vibration and torsional oscillation . 69
12.4 Electrical machine insulation electrical stresses . 69
12.5 Bearing currents . 70
13 Additional considerations for cage induction electrical machines fed by block-type

current source converters . 70
13.1 System characteristics (see Figure 35 and Figure 36) . 70
13.2 Losses and their effects . 71
13.3 Noise, vibration and torsional oscillation . 73
13.4 Electrical machine insulation electrical stresses . 73
13.5 Bearing currents . 73
13.6 Additional considerations for six-phase cage induction electrical machines . 74
14 Additional considerations for synchronous electrical machines fed by LCI . 74
14.1 System characteristics . 74
14.2 Losses and their effects . 75
14.3 Noise, vibration and torsional oscillation . 75
14.4 Electrical machine insulation electrical stresses . 75
14.5 Bearing currents . 75
15 Additional considerations for cage induction electrical machines fed by pulsed

current source converters (PWM CSI) . 76
15.1 System characteristics (see Figure 39) . 76
15.2 Losses and their effects . 77
15.3 Noise, vibration and torsional oscillation . 77
15.4 Electrical machine insulation electrical stresses . 77
15.5 Bearing currents . 77
16 Wound rotor induction (asynchronous) electrical machines supplied by voltage
source converters in the rotor circuit . 77
16.1 System characteristics . 77
16.2 Losses and their effects . 77

IEC TS 60034-25:2022 © IEC 2022 – 5 –
16.3 Noise, vibration and torsional oscillation . 78
16.4 Electrical machine insulation electrical stresses . 78
16.5 Bearing currents . 78
17 Other electrical machine/converter systems . 78
17.1 Drives supplied by cyclo-converters . 78
17.2 Wound rotor induction (asynchronous) electrical machines supplied by
current source converters in the rotor circuit . 80
18 Special consideration for standard fixed-speed induction electrical machines in the
scope of IEC 60034-12 when fed from voltage source converter and motor

requirements to be considered a converter capable motor . 80
18.1 General . 80
18.2 Torque derating during converter operation . 82
18.2.1 General . 82
18.2.2 Self-cooled motors . 83
18.2.3 Non self-cooled motors . 84
18.3 Losses and their effects . 84
18.4 Noise, vibrations and torsional oscillation . 84
18.5 Electrical machine insulation electrical stresses . 84
18.5.1 General . 84
18.5.2 Converter capable motor . 85
18.6 Bearing currents in converter capable motors . 85
18.7 Speed range mechanical limits. 86
18.7.1 General . 86
18.7.2 Maximum speed . 86
18.7.3 Minimum speed . 86
18.8 Overload torque capability . 87
18.9 Excess overload current limits . 87
18.9.1 General . 87
18.9.2 Converter capable motor . 87
18.10 Volts/Hz ratio and voltage boost. 87
18.11 Resonance. 87
18.12 Hazardous area operation . 87
18.12.1 General . 87
18.12.2 Converter capable motor . 88
18.13 Unusual service conditions . 89
18.13.1 Converter capable motors . 89
18.13.2 Unusual converter-fed applications . 89
19 Additional considerations for synchronous reluctance electrical machine fed by
voltage source converters . 89
19.1 System characteristics . 89
19.2 Losses and their effects . 89
19.3 Noise, vibration and torsional oscillation . 89
19.4 Electrical machine insulation electrical stresses . 89
19.5 Bearing currents . 89
19.6 Particular aspects of synchronous reluctance electrical machines . 90
Annex A (informative) Converter characteristics . 91
A.1 Converter control types . 91
A.1.1 General . 91
A.1.2 Converter type considerations . 92

– 6 – IEC TS 60034-25:2022 © IEC 2022
A.2 Converter output voltage generation (for voltage source converters) . 92
A.2.1 Pulse width modulation (PWM) . 92
A.2.2 Hysteresis (sliding mode) . 93
A.2.3 Influence of switching frequency . 93
A.2.4 Multi-level converters. 94
A.2.5 Parallel converter operation . 95
Annex B (informative) Output characteristics of 2 level voltage source converter
spectra . 96
Annex C (informative) Voltages to be expected at the power interface between

converter and electrical machine . 100
Annex D (informative) Speed and harmonic capability of converter capable induction
motor . 104
D.1 General . 104
D.2 Harmonic capability of converter capable motors . 104
D.3 Speed capability and derating in variable torque application . 105
D.4 Speed capability and derating in a constant torque application . 105
Bibliography . 107

Figure 1 – Torque/speed capability . 17
Figure 2 – Current required by motor . 18
Figure 3 – Examples of possible converter output voltage/frequency characteristics . 20
Figure 4 – Example for the dependence of the electrical machine losses caused by
harmonics P related to the losses P at operating frequency f , on the switching
h, f1 1
frequency f in case of 2 level voltage source converter supply . 25
s
Figure 5 – Example of measured losses P as a function of frequency f and supply type . 26
L
Figure 6 – Additional losses ∆P of an electrical machine (same electrical machine as
L
Figure 5) due to converter supply, as a function of pulse frequency f , at 50 Hz
p
rotational frequency . 27
Figure 7 – Relative fan noise as a function of fan speed . 29
Figure 8 – Vibration modes of the stator core . 30
Figure 9 – Typical surges at the terminals of an electrical machine fed from a PWM
converter . 33
Figure 10 – Typical voltage surges on one phase at the converter and at the electrical
machine terminals (2 ms/division) . 34
Figure 11 – Individual short rise-time surge from Figure 10 (1 μs/division) . 34
Figure 12 – Definition of the rise-time t of the voltage pulse at the electrical machine
r
terminals . 35
Figure 13 – First turn voltage as a function of the rise-time . 36
Figure 14 – Discharge pulse occurring as a result of converter generated voltage surge
at electrical machine terminals (100 ns/division) . 38
Figure 15 – Classification of bearing currents . 39
Figure 16 – Parasitic impedances to earth of drive system components . 40
Figure 17 – Common mode voltage a) determination b) waveform example . 41
Figure 18 – HF equivalent circuit diagram (a) of a motor (b) geometrical representation
of capacitances . 42
Figure 19 – Graphical representation of the different high frequency bearing current
types in the drive unit highlighting the involved physical components . 43

IEC TS 60034-25:2022 © IEC 2022 – 7 –
Figure 20 – Principle of circulating currents formation . 44
Figure 21 – Rotor ground current principle . 45
Figure 22 – Example of measured EDM-current pulses for a 400 V and 500 kW
induction motor in converter operation . 46
Figure 23 – Photographs of damaged motor bearings . 47
Figure 24 – Bonding strap from electrical machine terminal box to electrical machine
frame . 56
Figure 25 – Examples of shielded electrical machine cables and connections . 57
Figure 26 – Parallel symmetrical cabling of high-power converter and electrical
machine . 58
Figure 27 – Converter connections with 360º HF cable glands showing the Faraday
cage . 59
Figure 28 – Electrical machine end termination with 360º connection . 59
Figure 29 – Cable shield connection . 60
Figure 30 – Characteristics of preventative measures . 62
Figure 31 – Schematic of typical three-level converter . 65
Figure 32 – Output voltage and current from typical three-level converter . 65
Figure 33 – Typical first turn voltage ∆U (as a percentage of the line-to-ground voltage)
as a function of du/dt . 67
Figure 34 – Medium-voltage and high-voltage form-wound coil insulating and voltage
stress control materials . 68
Figure 35 – Schematic of block-type current source converter . 70
Figure 36 – Current and voltage waveforms of block-type current source converter . 70
Figure 37 – Influence of converter supply on the losses of a cage induction electrical
machine (frame size 315 M, design N) with rated values of torque and speed . 72
Figure 38 – Schematic and voltage and current waveforms for a synchronous electrical
machine supplied from a current source converter . 74
Figure 39 – Schematic of pulsed current source converter . 76
Figure 40 – Voltages and currents of pulsed current source converter . 76
Figure 41 – Schematic of cyclo-converter . 78
Figure 42 – Voltage and current waveforms of a cyclo-converter . 79
Figure 43 – Diagram comparing converter capable motor to converter duty motor . 81
Figure 44 – Fundamental voltage U as a function of operating frequency f . 82
1 1
Figure 45 – Torque derating factor for cage induction electrical machines of design N,
IC 411 (self-circulating cooling) as a function of operating frequency f (example) . 83
Figure A.1 – Effects of switching frequency on electrical machine and converter losses. 93
Figure A.2 – Effects of switching frequency on acoustic noise . 94
Figure A.3 – Effects of switching frequency on torque ripple . 94
Figure B.1 – Waveform of line-to-line voltage U for voltage source converter supply
LL
with switching frequency f = 30 × f (example) . 96
s 1
Figure B.2 – Typical output voltage frequency spectra for a constant frequency PWM
control versus hysteresis control . 97
Figure B.3 – Typical output voltage frequency spectra for random frequency PWM
versus hysteresis control . 97
Figure B.4 – Typical output voltage frequency spectra for a two-phase modulated
control versus hysteresis modulation . 98

– 8 – IEC TS 60034-25:2022 © IEC 2022
Figure B.5 – Typical time characteristics of electrical machine current for a Constant
frequency PWM control versus hysteresis control . 98
Figure B.6 – Typical time characteristics of electrical machine current for a two-phase

modulated control versus hysteresis modulation . 99
Figure C.1 – Example of typical voltage curves and parameters of a two level inverter
versus time at the electrical machine terminals (phase to phase voltage; taken from
IEC TS 61800-8) . 100
Figure D.1 – Derating curve for harmonic voltages . 105
Figure D.2 – Torque capability at reduced speeds due to the effects of reduced cooling

(applyies to 50 Hz or 60 Hz design N) . 106

Table 1 – Significant factors affecting torque/speed capability . 19
Table 2 – Electrical machine design considerations . 22
Table 3 – Electrical machine parameters for the tuning of the converter . 23
Table 4 – Operating voltage at the terminals in units of U where the electrical
N
machines may operate reliably without special agreements between manufacturers and
system integrators . 37
Table 5 – Different grades of roller bearing damages . 48
Table 6 – Effectiveness of bearing current counter measures . 52

IEC TS 60034-25:2022 © IEC 2022 – 9 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 25: AC electrical machines used in power drive systems –
Application guide
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (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, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; a
...