ISO 21782-6:2019

Electrically propelled road vehicles - Test specification for electric propulsion components - Part 6: Operating load testing of motor and inverter

This document specifies operating load tests and test criteria for motor and inverter designed as a voltage class B electric propulsion system for electrically propelled road vehicles.

Véhicules routiers à propulsion électrique — Spécification d'essai pour les composants de propulsion électrique — Partie 6: Test de charge de fonctionnement du moteur et du variateur

General Information

• Status: Published
• Publication Date: 28-Aug-2019
• ICS: 43.120 - Electric road vehicles
• Technical Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Drafting Committee: ISO/TC 22/SC 37/WG 4 - Systems and components connected to electric propulsion systems
• Current Stage: 9060 - Close of review
• Completion Date: 04-Mar-2030

Overview

ISO 21782-6:2019 - "Electrically propelled road vehicles - Test specification for electric propulsion components - Part 6: Operating load testing of motor and inverter" specifies operating-load tests and acceptance criteria for motors and inverters designed as a voltage class B electric propulsion system for electrically propelled road vehicles. The standard defines endurance and verification tests that evaluate mechanical and electrical robustness under repeated high-load and transient conditions, and it links to general definitions and test conditions in ISO 21782-1:2019.

Key topics and technical requirements

• Scope and linkage

  • Applies to motor and inverter components of voltage class B propulsion systems.
  • Normative references include ISO 21782-1 for general test conditions and definitions.

• Motor operation endurance tests

  • High acceleration/deceleration endurance test: evaluates fatigue on bearings, end rings, shaft key, rotor fixture, rotor, and position sensor by repeating intermittent maximum speed cycles. Cycle counts are ranked (C → S) - e.g., C = 100 000 cycles (bidirectional), S = 500 000 (bidirectional); single-direction rankings are higher (C = 200 000, S = 1 000 000). Pre/post-energizing measurements and optional disassembly criteria (back-EMF ±5%, position sensor ±5° electrical, torque ±5%) are specified.
  • Maximum torque endurance test: stresses components under intermittent maximum torque at constant speed. Ranks and cycle counts are provided (C = 300 000 up to S = 2 000 000). Temperature control to saturation during permissible continuous load is required.

• Inverter operation endurance tests

  • Cyclic test: verifies inverter endurance under repeated load transients (details and test parameters defined in the standard).

• Rotor breakdown strength verification

  • Spin test and other verification methods to confirm rotor mechanical integrity.

• Measurements & acceptance criteria

  • Key measurable criteria include back-EMF, torque–speed characteristics, position sensor waveform, vibration, and post-test physical inspection (bearings, end ring, shaft key, rotor, adhesives).

• Test reporting

  • Test report contents and an informative annex template are included.

Practical applications and users

• Who uses it: OEMs, propulsion component suppliers, independent test laboratories, validation and reliability engineers, and procurement teams specifying component durability.
• Typical uses: component qualification, supplier benchmarking, durability ranking, validation during design iteration, and contractual verification for motor and inverter acceptance.

Related standards

• ISO 21782-1:2019 - General test conditions and definitions for testing electric propulsion components (normative reference).
• Other parts of the ISO 21782 series address complementary test specifications for propulsion components.

Keywords: ISO 21782-6:2019, electrically propelled road vehicles, motor/inverter testing, operating load testing, endurance test, high acceleration test, maximum torque endurance, spin test, voltage class B.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21782-6
First edition
2019-08
Electrically propelled road vehicles —
Test specification for electric
propulsion components —
Part 6:
Operating load testing of motor and
inverter
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Tests and requirements . 1
4.1 Operation endurance tests of motor . 1
4.1.1 High acceleration/deceleration endurance test . 1
4.1.2 Maximum torque endurance test . 6
4.1.3 Over speed test .10
4.2 Operation endurance test of inverter .14
4.2.1 Cyclic test .14
4.3 Breakdown strength verification test of rotor .17
4.3.1 Spin test .17
5 Test report .18
Annex A (informative) Test report .19
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO , also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO /IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO /IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO 's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO /TC 22, Road Vehicles, Subcommittee SC 37,
Electrically propelled vehicles.
A list of all parts in the ISO 21782 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 21782-6:2019(E)
Electrically propelled road vehicles — Test specification
for electric propulsion components —
Part 6:
Operating load testing of motor and inverter
1 Scope
This document specifies operating load tests and test criteria for motor and inverter designed as a
voltage class B electric propulsion system for electrically propelled road vehicles.
2 Normative references
The following documents are referred to in the text 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.
ISO 21782-1:2019, Electrically propelled road vehicles — Test specification for components for electric
propulsion — Part 1: General test conditions and definitions
3 Terms and definitions
For the purposes of this document, the terms, definitions and abbreviated terms given in
ISO 21782-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Tests and requirements
4.1 Operation endurance tests of motor
4.1.1 High acceleration/deceleration endurance test
4.1.1.1 General
The purpose of this test is to evaluate and rank the strength for the components – bearing, end ring,
motor shaft key, rotor fixture, rotor, and position sensor – which are affected by mechanical fatigue by
repeating the intermittent maximum speed of motor. The test is set considering repeated operations
at the upper specification limits of the motor. Unless otherwise, the test method can be decided by the
supplier and customer.
4.1.1.2 Test diagram
The test diagram is shown in Figure 1. The test motor is operated by opposing dynamometer on the
motor test bench.
Key
1 DUT
2 motor
3 dynamometer
4 torque/speed detector
5 torque/speed meter
6 motor torque (in Nm)
-1
7 motor speed (in min )
Figure 1 — Diagram for high acceleration/deceleration endurance test of motor
4.1.1.3 Test conditions
Test conditions are shown in Table 1.
Table 1 — Conditions for high acceleration/deceleration endurance test of motor
Test conditions Value Remark
Ambient Room temperature (RT) and humidity as defined
conditions in ISO 21782-1:2019, 5.4.
Coolant temperature Maximum temperature for unlimited operating — In case of liquid
capability cooling
— Ethylene glycol and
propylene glycol as
example of coolant
Coolant f low Liquid Minimum flow rate for unlimited operating
rate capability
Air Minimum flow rate for unlimited operating
capability
4.1.1.4 Test procedure
The test pattern is shown in Figure 2. Rotation in clockwise and counter-clockwise direction is repeated
at the maximum speed of the motor specifications. The load is no load.
The number of cycles shall be decided by agreement between the supplier and customer referring to
Table 2 or Table 3.
2 © ISO 2019 – All rights reserved

a) Test pattern for motor with bidirectional rotation
b) Test pattern for motor with single directional rotation
Key
t time (in s)
-1
n motor speed (in min )
-1
n maximum speed (in min )
m
s 1 cycle
t holding time (in s)
Figure 2 — High acceleration/deceleration endurance test pattern for motor
The acceleration rate in Figure 2 is equivalent to that of the targeted vehicle and is decided between
the supplier and customer. The time "t " at the maximum speed and zero speed shall be reduced to
a technically possible minimum (e.g. 1 s). In case of a motor with single directional rotation, only the
positive speed shall be considered as shown in Figure 2 b).
This test aims to evaluate mechanical endurance. Endurance is displayed according to the rank in
Table 2 in case of a motor with bidirectional rotation, and in Table 3 in case of a motor with single
directional rotation.
Table 2 — Number of cycles in high acceleration/deceleration endurance test for motor with
bidirectional rotation
Ranks Number of cycles
S 500 000
A 300 000
B 200 000
C 100 000
Table 3 — Number of cycles in high acceleration/deceleration endurance test for motor with
single directional rotation
Ranks Number of cycles
S 1 000 000
A 600 000
B 400 000
C 200 000
4.1.1.5 Test requirements
4.1.1.5.1 General
The cyclic test shall be started from C rank which is listed in Table 2 and Table 3 with the motor phases
open. Confirmation by energizing and disassembling shall be conducted after the high acceleration/
deceleration endurance test, in order to analyse and confirm that changes before and after energizing
are within the respective criteria listed in Table 4. If it is confirmed by agreement between the supplier
and customer that this motor is clearly of a higher proof than C rank, continue cyclic test to the next
upper rank. If the target cycle has been achieved, disassembling shall be conducted and the criteria
for disassembling are listed in Table 5. If failure has occurred during a cyclic test, the motor shall be
disassembled and analysed by agreement between the supplier and customer. The rank of the motor
shall be decided based on the results of energizing and post-test analysis. If changes before and after
energizing are not within the criteria listed in Table 5 or any failure or anomaly occurs post-test
analysis, the motor shall belong to a lower rank.
4.1.1.5.2 Energizing
Before conducting this test, the data of the test listed in Table 4 shall be obtained in order to be able to
compare the data before and after this test.
— Back electromotive force (back-EMF) measurement
The back-EMF of the motor is measured at the 10 % of maximum speed driven externally. They
shall be within ±5 % difference before and after the test.
NOTE If the type of DUT is different from a permanent magnet motor, this measurement can be omitted.
— Measurement of origin position and waveform of position sensor
The difference in the back-EMF waveform of the reference phase and the origin position of the
position sensor at the 10 % of maximum speed driven externally shall be measured. They shall be
within ±5° difference in electrical angle before and after the test.
— Torque – speed characteristics
The motor torque, motor input voltage, inverter output current, and motor speed shall be measured
using the load test bench at the operating point "a" and "c" of ISO 21782-1:2019, Figure 1. The
difference in torque before and after the test shall be within ±5 %.
4 © ISO 2019 – All rights reserved

— Measurement of vibration
The generated vibrations of the motor during acceleration by the inverter to the maximum speed
shall be measured. The acceleration rate shall be adequately slow. The vibration data before and
after the test shall be compared to determine if there has been no significant increase. The changes
in the vibration values shall be judged by an agreement between the supplier and customer.
Criteria of energizing is shown in Table 4.
Table 4 — Criteria of energizing
Measurement items Condition Criteria
Back-EMF 10 % of maximum speed Within ±5 % difference before
and after the test
Origin position and waveform Specified speed Within ±5° difference in electri-
of position sensor cal angle before and after the test
Torque - speed characteristics Operating point "a" and "c" Within ±5 % difference in the
torque before and after the test
Vibration During acceleration to the max- No significant increase
imum speed by inverter
(acceleration rate: adequately
slow)
4.1.1.5.3 Disassembling
The motor shall be disassembled, and each part shall be investigated. The items and criteria are shown
in Table 5.
Differences which adversely affect motor performance shall not occur after disassembling. Details of
criteria shall be agreed by the supplier and customer.
NOTE Disassembling is optional and is agreed by the supplier and customer in case of abnormalities in the
non-destructive examinations.
Table 5 — Criteria of disassembling
Parts/places Details of investigation Criteria
Bearing Transferred side scratch, grease degra- Scratch not leading to noise
dation, creep
Grease degradation < reference value
No creep
End ring Deformation, crack No large deformation
No crack
Motor shaft key Deformation, wear No large deformation
No large wear
Rotor fixture Peeling off of adhesive deformation No peeling
(magnet, cage, etc.)
Outer circumference of Deformation, wear No large deformation
rotor
No large wear
(According to external size)
Position sensor Deviation of position (number of poles Allowable thrust displacement
is also indicated)
Allowable concentricity
4.1.2 Maximum torque endurance test
4.1.2.1 General
The purpose of this test is to evaluate and rank the strength for the components – motor shaft key, rotor
fixture, shaft tightening part, and stator fixtures – which are affected by mechanical fatigue by repeating
the intermittent maximum torque of the motor. The test is set considering repeated operations at the
upper specification limits of the motor. The test method can be decided by the supplier and customer.
4.1.2.2 Test diagram
The test diagram is shown in Figure 3. The test motor shall be operated at constant speed at the rated
voltage outlined in ISO 21782-1 on the motor test bench.
Key
1 DUT 7 motor torque (in Nm)
-1
2 motor 8 motor speed (in min )
3 inverter 9 power meter
4 load 10 motor input current (in A)
5 torque/speed detector 11 thermometer
6 torque/speed meter 12 motor temperature (in °C)
Figure 3 — Diagram for maximum torque endurance test of motor
4.1.2.3 Test conditions
Test conditions are shown in Table 6.
Table 6 — Conditions for maximum torque endurance test of motor
Test conditions Value Remark
Ambient RT and humidity as defined in ISO 21782-
conditions 1:2019, 5.4.
Coolant temperature Maximum temperature for unlimited operating — In case of liquid
capability cooling
— Ethylene glycol and
propylene glycol as
example of coolant
6 © ISO 2019 – All rights reserved

Table 6 (continued)
Test conditions Value Remark
Coolant flow Liquid Minimum flow rate for unlimited operating
rate capability
Air Minimum flow rate for unlimited operating
capability
4.1.2.4 Test procedure
The test pattern is shown in Figure 4. The constant speed shall be set between operating point "d"
and "a" of ISO 21782-1:2019, Figure 1. The motor torque shall be operated on M and –M as shown
t=2 t=2
in Figure 4. Time parameter t , t and t in Figure 4 shall be as listed in Table 7. The tests shall be
1 2 3
conducted by repeating the number of cycles according to the corresponding rank shown in Table 8.
The temperature of each part of the motor shall be controlled so that they are substantially equal to the
saturation temperature during operation at permissible continuous load as shown in Figure 5.
NOTE To protect the torque meter, the test can be performed without it, after setting up the maximum
torque. In that case, torque meter can be replaced by power meter to measure motor input currents.
Key
t time (in s)
M torque (in Nm)
M maximum motoring torque for duration of t = 2 (in Nm)
t=2 0
-M maximum regenerating torque for duration of t = 2 (in Nm)
t=2 0
s 1 cycle
t , t , t time parameter
1 2 3
Figure 4 — Maximum torque endurance pattern for motor
Table 7 — Description of time parameter in Figure 4
Time
Requirements
parameters
t This shall be reduced to technically possible minimum.
t This should be shorter than 1 s.
t This shall be controlled so that the average output power becomes the same as the per-
missible continuous load of the motor.
Key
t time (in s)
M torque (in Nm)
T temperature (in °C)
M maximum motoring torque for duration of t = 2 (in Nm)
t=2 0
-M maximum regenerating torque for duration of t = 2 (in Nm)
t=2 0
T saturation temperature during rated output power operation (in °C)
s
1 motor torque
2 temperature of motor
Figure 5 — Long time span view of Figure 4
Table 8 — Number of cycles in maximum torque endurance test for motor
Ranks Number of cycles
S 2 000 000
A 1 000 000
B 500 000
C 300 000
8 © ISO 2019 – All rights reserved

4.1.2.5 Test requirements
4.1.2.5.1 General
The cyclic test shall be started from C rank which is listed in Table 8. Confirmation by energizing and
disassembling
...