ISO 21782-3:2019

INTERNATIONAL ISO
STANDARD 21782-3
First edition
2019-08
Electrically propelled road vehicles —
Test specification for electric
propulsion components —
Part 3:
Performance testing of the motor and
the 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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
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 Abbreviated terms . 1
5 Tests . 1
5.1 Motor test . 1
5.1.1 Measurement of loss and efficiency . 1
5.1.2 Temperature rise test. 4
5.1.3 Torque characteristic test . 5
5.1.4 Cogging torque test . 7
5.2 Inverter test . 9
5.2.1 Measurement of loss, efficiency and conversion rate . 9
5.2.2 Temperature rise test.11
5.3 Chopper test .13
5.3.1 Measurement of loss, efficiency and conversion rate .13
5.3.2 Temperature rise test.16
6 Test reports .17
Annex A (informative) Precautions for measuring motor/inverter loss and efficiency .18
Annex B (informative) Test report .20
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 21782-3:2019(E)
Electrically propelled road vehicles — Test specification
for electric propulsion components —
Part 3:
Performance testing of the motor and the inverter
1 Scope
This document specifies performance tests for the motor and the 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 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.
ISO 21782-1, Electrically propelled road vehicles — Test specification for electric propulsion components
— Part 1: General test conditions and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions 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 Abbreviated terms
For the purposes of this document, the abbreviated terms given in ISO 21782-1 apply.
5 Tests
5.1 Motor test
5.1.1 Measurement of loss and efficiency
5.1.1.1 General
The purpose of this test is to operate the motor under the specified operating conditions and to measure
the loss and efficiency of the motor in order to ensure that the performance is as designed.
5.1.1.2 Test diagram
The test diagram is shown in Figure 1.
Either the two-wattmeter method or the three-wattmeter method may be used for the three-phase
power measurement.
Using the three-wattmeter method is recommended.
Key
1 DUT
2 motor
3 inverter
4 load
5 torque/speed detector
6 spectrum analyser/power meter
7 torque/speed meter
8 motor input current (in A)
9 motor input voltage (in V)
10 motor torque (in Nm)
-1
11 motor speed (in min )
Figure 1 — Diagram for measurement of loss and efficiency of the motor
5.1.1.3 Test conditions
The test conditions are shown in Table 1.
Table 1 — Conditions for measurement of loss and efficiency of the motor
Test conditions Value Remark
Inverter input voltage Rated voltage as defined in ISO 21782-1:2019, 3.22. For the inverter input
voltage tolerance, see
ISO 21782-1:2019, 5.3.
Ambient conditions Room temperature (RT) and humidity as defined in
ISO 21782-1:2019, 5.4.
2 © ISO 2019 – All rights reserved

Table 1 (continued)
Test conditions Value Remark
Coolant temperature Maximum temperature for unlimited operating capability — In case of liquid
cooling
— Ethylene glycol and
propylene glycol as
examples of coolant
— If technically
feasible, the tests
shall be performed at
coolant temperature
of 65 °C. Otherwise
the deviation shall be
documented in the
test report.
Coolant flow Liquid Minimum flow rate for unlimited operating capability
rate
Air Minimum flow rate for unlimited operating capability
Operating point Test points as defined in ISO 21782-1:2019, Figure 1
— "a", "a’", "b", "p " to "p " (optional "e", "e’", "f", "p ’" to "p ’")
1 10 1 10
Switching frequency The frequency shall be agreed between the supplier and
customer.
Operating time — The operating points "a", "a’", "p ", "p ", "p ", "p ", "p ", For regenerative
1 3 5 7 9
"p ": 2 s or 10 s (optional 30 s, 60 s) operating points, the
same operating time
— The operating point "b": 1 800 s
applies as for corre-
sponding motoring
— The operating points "p ", "p ", "p ", "p ": 1 800 s or maxi-
2 4 6 8
operating points.
mum allowable time for temperature protection
5.1.1.4 Test procedure
1) The test motor shall be operated at specified operating points for the operating time defined in
Table 1. Motor input power, output torque and speed shall be recorded. Each average of the last
one second of the records shall be used. See Annex A for information about the input power
measurement.
2) The loss and efficiency shall be calculated by using Formulae (1) and (2):
P
mo
η =×100 (1)
m
P
mi
PP=− P (2)
ml mi mo
where
η is the efficiency of the motor (in %);
m
P is the motor output power (in W);
mo
P is the motor input power (in W);
mi
P is the loss of the motor (in W).
ml
The measurement of regenerate operation may be decided by agreement between the supplier and
customer.
5.1.2 Temperature rise test
5.1.2.1 General
The purpose of this test is to operate the motor under the specified conditions and to measure the
temperature rise in the motor in order to ensure that the motor thermal performance is as designed.
5.1.2.2 Test diagram
The test diagram is shown in Figure 2.
Key
1 DUT
2 motor
3 inverter
4 load
5 torque/speed detector
6 thermometer
7 torque/speed meter
8 measurement point temperature (in °C)
9 motor torque (in Nm)
-1
10 motor speed (in min )
Figure 2 — Diagram for temperature rise test of the motor
5.1.2.3 Test conditions
The test conditions are shown in Table 2.
Table 2 — Conditions for temperature rise test of the motor
Test conditions Value Remark
Inverter input voltage Rated voltage as defined in ISO 21782-1:2019, 3.22. For the inverter input
voltage tolerance, see
ISO 21782-1:2019, 5.3.
Ambient conditions RT and humidity as defined in ISO 21782-1:2019, 5.4.
4 © ISO 2019 – All rights reserved

Table 2 (continued)
Test conditions Value Remark
Coolant temperature Maximum temperature for unlimited operating capability — In case of liquid
cooling
— Ethylene glycol and
propylene glycol as
examples of coolant
— If technically
feasible, the tests
shall be performed at
coolant temperature
of 65 °C. Otherwise
the deviation shall be
documented in the
test report.
Coolant flow Liquid Minimum flow rate for unlimited operating capability
rate
Air Minimum flow rate for unlimited operating capability
Operating point The points as defined in ISO 21782-1:2019, Figure 1 May be set by agree-
ment between the
— "a", "b"
supplier and customer.
Switching frequency The frequency shall be set by agreement between the
supplier and customer.
Operating time — The operating point "a": 2 s or 10 s
— The operating point "b": 1 800 s
5.1.2.4 Test procedure
The test motor shall be operated at specified operating points, and the temperature at the measurement
points shall be recorded.
For each torque-speed point, after the operating time as defined in Table 2 passes, the temperature
shall be recorded.
An inverter that has the ability to operate continuously at the maximum torque point may be used.
The temperature of coil shall be measured at the points assumed as the highest. The measurement
points in the coil and other measurement points can be added by agreement between the supplier and
customer.
5.1.3 Torque characteristic test
5.1.3.1 General
The purpose of this test is to operate the motor under the specified operating conditions and to check
the torque characteristics in order to ensure that the motor performance is as designed.
5.1.3.2 Test diagram
The test diagram is shown in Figure 3.
...