IEC TS 62898-2:2018

IEC TS 62898-2 ®
Edition 1.0 2018-09
TECHNICAL
SPECIFICATION
colour
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
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