IEC TS 62898-2:2018
(Main)Microgrids - Part 2: Guidelines for operation
Microgrids - Part 2: Guidelines for operation
IEC TS 62898-2:2018 provides guidelines for operation of microgrids. Microgrids considered in this document are alternating current (AC) electrical systems with loads and distributed energy resources (DER) at low or medium voltage level. This document does not cover direct current (DC) microgrids.
IEC TS 62898-2 applies to operation and control of microgrids, including:
• operation modes and mode transfer;
• energy management system (EMS) and control of microgrids;
• communication and monitoring procedures;
• electrical energy storage;
• protection principle covering: principle for non-isolated microgrid, isolated microgrid, anti-islanding, synchronization and reclosing, power quality;
• commissioning, maintenance and test.
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IEC TS 62898-2 ®
Edition 1.0 2018-09
TECHNICAL
SPECIFICATION
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inside
Microgrids –
Part 2: Guidelines for operation
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IEC TS 62898-2 ®
Edition 1.0 2018-09
TECHNICAL
SPECIFICATION
colour
inside
Microgrids –
Part 2: Guidelines for operation
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01 ISBN 978-2-8322-6042-5
– 2 – IEC TS 62898-2:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Operation modes . 13
4.1 General . 13
4.2 Non-isolated microgrid . 13
4.2.1 General . 13
4.2.2 Grid-connected mode . 13
4.2.3 Island mode . 14
4.2.4 Mode transfer of non-isolated microgrids . 14
4.3 Isolated microgrid . 15
4.3.1 General . 15
4.3.2 Structure of the isolated microgrids . 15
4.3.3 Voltage response characteristics . 16
4.3.4 Frequency response characteristics . 16
5 Control of microgrids . 16
5.1 General . 16
5.2 Control of the non-isolated microgrid . 18
5.2.1 Control of the grid-connected mode . 18
5.2.2 Control of the island mode . 19
5.3 Control of the isolated microgrid . 20
6 Communication and monitoring . 21
6.1 General . 21
6.2 Communications of microgrids . 22
6.2.1 General . 22
6.2.2 Communications between non-isolated microgrids and the utility grid . 22
6.2.3 Communications inside the microgrids . 22
6.3 Monitoring the DER . 22
6.4 Monitoring the switching devices for non-isolated microgrids . 22
6.5 Monitoring the switching devices for isolated microgrids . 23
7 Electrical energy storage . 23
7.1 General . 23
7.2 EES in non-isolated microgrids . 23
7.2.1 Requirements for EES in grid-connected mode . 23
7.2.2 Requirements for EES in island mode . 23
7.2.3 Requirements for EES in mode transfer . 24
7.3 EES management . 24
8 Protection principle for microgrids. 24
8.1 General . 24
8.2 Principle for protection in a non-isolated microgrid . 25
8.3 Reclosing with synchronization in a non-isolated microgrid . 25
8.4 Principle for protection in an isolated microgrid . 25
9 Power quality and EMC of microgrids . 25
9.1 Power quality in non-isolated microgrids . 25
9.2 Power quality in isolated microgrids . 26
9.3 EMC in microgrids . 26
10 Maintenance and test of microgrids . 26
10.1 General . 26
10.2 Maintenance . 26
10.3 Test . 27
Annex A (informative) Business use case A: Improving reliability and securing the
energy supply by islanding . 28
Annex B (informative) Business use case B: Electrifying remote areas and using
renewable energy sources . 31
Annex C (informative) Business use case C: Reducing energy costs for microgrid
users . 33
Annex D (informative) Business use case D: Optimizing local resources to provide
services to the grid/disaster preparedness . 35
Annex E (informative) Example of power factor requirements cited in some standards . 36
Bibliography . 37
Figure 1 – Example for a non-isolated microgrid . 17
Figure 2 – Example for an isolated microgrid . 18
Figure 3 – The P-f control in isolated microgrid . 20
Figure B.1 – One of the actual examples of mainly-isolated microgrids used for
electrification in far rural area . 32
Figure C.1 – Principle scheme of customer energy management and information
exchange with upstream grid . 34
Table 1 – Example for the isolated microgrid frequency response of 50 Hz . 21
Table E.1 – Power factor requirements . 36
– 4 – IEC TS 62898-2:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MICROGRIDS –
Part 2: Guidelines for operation
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; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or relia
...
IEC TS 62898-2 ®
Edition 1.1 2023-11
CONSOLIDATED VERSION
TECHNICAL
SPECIFICATION
colour
inside
Microgrids –
Part 2: Guidelines for operation
All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
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committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
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If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TS 62898-2 ®
Edition 1.1 2023-11
CONSOLIDATED VERSION
TECHNICAL
SPECIFICATION
colour
inside
Microgrids –
Part 2: Guidelines for operation
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01 ISBN 978-2-8322-7826-0
IEC TS 62898-2 ®
Edition 1.1 2023-11
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Microgrids –
Part 2: Guidelines for operation
– 2 – IEC TS 62898-2:2018+AMD1:2023 CSV
© IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Operation modes . 13
4.1 General . 13
4.2 Non-isolated microgrid . 13
4.2.1 General . 13
4.2.2 Grid-connected mode . 13
4.2.3 Island mode . 14
4.2.4 Mode transfer of non-isolated microgrids . 14
4.3 Isolated microgrid . 15
4.3.1 General . 15
4.3.2 Structure of the isolated microgrids . 15
4.3.3 Voltage response characteristics . 16
4.3.4 Frequency response characteristics . 16
5 Control of microgrids . 16
5.1 General . 16
5.2 Control of the non-isolated microgrid . 19
5.2.1 Control of the grid-connected mode . 19
5.2.2 Control of the island mode . 20
5.3 Control of the isolated microgrid . 21
6 Communication and monitoring . 23
6.1 General . 23
6.2 Communications of microgrids . 23
6.2.1 General . 23
6.2.2 Communications between non-isolated microgrids and the utility grid . 23
6.2.3 Communications inside the microgrids . 24
6.3 Monitoring the DER . 24
6.4 Monitoring the switching devices for non-isolated microgrids . 24
6.5 Monitoring the switching devices for isolated microgrids . 24
7 Electrical energy storage . 24
7.1 General . 24
7.2 EES in non-isolated microgrids . 25
7.2.1 Requirements for EES in grid-connected mode . 25
7.2.2 Requirements for EES in island mode . 25
7.2.3 Requirements for EES in mode transfer . 25
7.3 EES management . 26
8 Protection principle for microgrids. 26
8.1 General . 26
8.2 Principle for protection in a non-isolated microgrid . 26
8.3 Reclosing with synchronization in a non-isolated microgrid . 26
8.4 Principle for protection in an isolated microgrid . 27
9 Power quality and EMC of microgrids . 27
9.1 Power quality in non-isolated microgrids . 27
© IEC 2023
9.2 Power quality in isolated microgrids . 27
9.3 EMC in microgrids . 27
10 Maintenance and test of microgrids . 28
10.1 General . 28
10.2 Maintenance . 28
10.3 Test . 28
Annex A (informative) Business use case A: Improving reliability and securing the
energy supply by islanding . 29
Annex B (informative) Business use case B: Electrifying remote areas and using
renewable energy sources . 32
Annex C (informative) Business use case C: Reducing energy costs for microgrid
users . 34
Annex D (informative) Business use case D: Optimizing local resources to provide
services to the grid/disaster preparedness . 36
Annex E (informative) Example of power factor requirements cited in some standards . 37
Bibliography . 38
Figure 1 – Example for a non-isolated microgrid . 18
Figure 2 – Example for an isolated microgrid . 19
Figure 3 – The P-f control in isolated microgrid . 22
Figure B.1 – One of the actual examples of mainly-isolated microgrids used for
electrification in far rural area . 33
Figure C.1 – Principle scheme of customer energy management and information
exchange with upstream grid . 35
Table 1 – Example for the isolated microgrid frequency response of 50 Hz . 22
Table E.1 – Power factor requirements . 37
– 4 – IEC TS 62898-2:2018+AMD1:2023 CSV
© IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MICROGRIDS –
Part 2: Guidelines for operation
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; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative r
...
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