IEC TR 62898-4:2023

Microgrids - Part 4: Use cases

IEC TR 62898-4:2023 which is a technical report, provides a set of use cases related to microgrids, as a form of "decentralized energy system". Decentralized energy systems are small energy systems containing loads and distributed energy resources (generation, storage) with decentralized management for energy supply. This document completes the SC 8B roadmap for decentralized electrical energy systems. The goal is to explain the methodology retained on the microgrid sub-domain, which is a kind of decentralized system. This methodology, based on IEC 62913-1, describes high-level use cases (business use cases) covering the main typical usage of microgrids, and details some of them through system use cases. The proposed list of use cases is a first version, proposed for review; the goal is to cover all use cases with the same level of depth.

General Information

• Status: Published
• Publication Date: 03-Apr-2023
• ICS: 29.240.01 - Power transmission and distribution networks in general
• Technical Committee: SC 8B - Decentralized electrical energy systems
• Current Stage: PPUB - Publication issued
• Start Date: 12-Apr-2023
• Completion Date: 04-Apr-2023

Standards Content (Sample)

IEC TR 62898-4
®

Edition 1.0 2023-04
TECHNICAL
REPORT

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Microgrids –
Part 4: Use cases

IEC TR 62898-4:2023-04(en)

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IEC TR 62898-4

®


Edition 1.0 2023-04




TECHNICAL



REPORT








colour

inside










Microgrids –

Part 4: Use cases


























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ELECTROTECHNICAL


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ICS 29.240.01 ISBN 978-2-8322-6645-8



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– 2 – IEC TR 62898-4:2023 © IEC 2023
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 11
4 Overview of the document . 12
5 Role model associated to decentralized electrical energy systems. 12
5.1 Role model based on SGAM . 12
5.2 Business roles . 13
5.3 System roles . 15
5.4 Clarifications on some roles and further detailing concepts . 20
6 Microgrids use cases . 22
6.1 General . 22
6.2 List of business use cases identified . 22
6.3 Use case methodology applied to microgrid domain . 23
6.4 Guarantee a continuity in load service by islanding (BUC A) . 25
6.4.1 General . 25
6.4.2 Scope . 25
6.4.3 Objectives . 25
6.4.4 Operation of use case and technical issues . 26
6.5 Electrify areas using renewable energy resources (BUC B) . 29
6.5.1 General . 29
6.5.2 Scope . 29
6.5.3 Objectives . 29
6.5.4 Operation of use case and technical issues . 29
6.6 Optimize local resources to provide services to customers inside the
microgrid (BUC C) . 30
6.6.1 Scope . 30
6.6.2 Objectives . 30
6.6.3 Operation and related technical issues . 31
6.7 Optimize local resources to provide services to the area EPS for disaster
preparedness and power quality (BUC D) . 33
6.7.1 Scope . 33
6.7.2 Objectives . 33
6.7.3 Operation of use case and technical issues . 34
6.8 Develop larger energy systems by interconnection of isolated microgrids
(BUC E) . 34
6.8.1 Scope . 34
6.8.2 Objectives . 34
6.8.3 Operation of use case and technical issues . 35
6.9 Optimize energy supply cost and exploitation of local assets inside
community-run distribution utility by managing local resources (BUC F) . 36
6.9.1 Scope . 36
6.9.2 Objectives . 37
6.9.3 Operation and related technical issues . 37

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IEC TR 62898-4:2023 © IEC 2023 – 3 –
6.10 List of system use cases . 40
7 Coordination with other IEC Standards . 47
7.1 Links with IEC 61968-1 . 47
7.2 Links with IEC 61968-5 . 49
7.3 Links with IEC TR 61850-90-23 . 51
7.4 Links with the IEC 62898 series . 53
7.4.1 General . 53
7.4.2 Links with IEC TS 62898-1 . 53
7.4.3 Links with IEC TS 62898-2 . 53
7.4.4 Links with IEC TS 62898-3 series . 54
7.5 VPP related standards . 56
7.6 Prosumer electrical installations . 58
8 Perspectives . 59
Annex A (informative) Business use case A, Guarantee a continuity in load service by
islanding the microgrid, in IEC 62559-2 template . 60
Annex B (informative) UML microgrid use case repository. 64
Bibliography . 65

Figure 1 – The Smart Grid Architecture Model (CEN-CENELEC-ETSI, 2014) . 13
Figure 2 – Schematic view of the different types of electric power systems . 21
Figure 3 – Graphic user guide for DER related terms and concepts . 22
Figure 4 – Schematic vision of the microgrids business use cases . 23
Figure 5 – Process for SUC edition for each BUC . 25
Figure 6 – Illustration of a microgrid for electrifying remote areas using renewable
energy resources . 30
Figure 7 – Representation of the power regulation and control of a microgrid . 33
Figure 8 – Illustration of an area with microgrids and local energy supply systems

without interconnection . 35
Figure 9 – Illustration of the connection between microgrids and local energy supply
systems of an area . 36
Figure 10 – Customer regulation and EMS connection options . 40
Figure 11 – Interface Reference Model (IEC 61968-1) . 48
Figure 12 – Architectural options for DERMS deployment (from IEC 61968-5) . 49
Figure 13 – Request-and-reply message exchange pattern for the creation of a DER
Group (from IEC 61968-5). 50
Figure 14 – Notification message exchange pattern for the creation of a DER Group
(from IEC 61968-5) . 51
Figure 15 – First set of sub-roles attached to a DER (microgrid) deduced from
IEC 61850-7-420 . 52
Figure 16 – Current role transpositions into LNs according to IEC 61850-7-420 . 53
Figure 17 – Function mapping among subparts in the IEC TS 62898-3 series . 54
Figure 18 – VPP composition diagram . 56
Figure 19 – Centralized control mode architecture . 57
Figure 20 – Decentralized control mode architecture. 57
Figure 21 – Example of prosumer’s low-voltage electrical installation . 58
Figure B.1 – UML microgrid use case repository . 64
Figure B.2 – System use case illustration . 64

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– 4 – IEC TR 62898-4:2023 © IEC 2023
Table 1 – Business roles of the domain . 13
Table 2 – System roles of the domain . 16
Table 3 – List of microgrids system use cases . 41

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IEC TR 62898-4:2023 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MICROGRIDS –

Part 4: Use cases

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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC TR 62898-4 has been prepared by subcommittee SC 8B: Decentralized electrical energy
systems, of IEC technical committee 8: System aspects of electrical energy supply. It is a
Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
8B/120/DTR 8B/142/RVDTR

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.

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– 6 – IEC TR 62898-4:2023 © IEC 2023
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in the IEC 62898 series, published under the general title Microgrids, can be
found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

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IEC TR 62898-4:2023 © IEC 2023 – 7 –
INTRODUCTION
This document provides a set of use cases related to microgrids, as a form of "decentralized
energy system". Decentralized energy systems are small energy systems containing loads and
distributed energy resources (generation, storage) with decentralized management for energy
supply. This document completes the SC 8B roadmap for decentralized electrical energy
systems. The goal is to explain the methodology retained on the microgrid sub-domain, which
is a kind of decentralized system. This methodology, based on IEC 62913-1, describes high-
level use cases (business use cases) covering the main typical usage of microgrids, and details
some of them through system use cases. The proposed list of use cases is a first version,
proposed for review; the goal is to cover all use cases with the same level of depth.

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– 8 – IEC TR 62898-4:2023 © IEC 2023
MICROGRIDS –

Part 4: Use cases



1 Scope
In line with the methodology specified in IEC SRD 62913-1, this document describes business
use cases (high-level use cases covering the main typical usage of microgrids) and details
some of them. System use cases linked to those business use cases are listed and briefly
described for contextualizing the main functions to be performed for managing microgrids.
Ultimately, the goal of this document is to provide a consistent level of detail for all business
use cases. The document details the methodology retained to develop system use cases from
the business use cases.
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.
IEC SRD 62913-1, Generic smart grid requirements – Part 1: Specific application of the Use
case methodology for defining generic smart grid requirements according to the IEC systems
approach
3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC SRD 62913-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
black start
start-up of an electric power system from a blackout through internal energy resources
[SOURCE: IEC 60050-617:2017, 617-04-24]
3.1.2
distributed energy resources
DER
generators (with their auxiliaries, protection and connection equipment), including loads having
a generating mode (such as electrical energy storage systems), connected to a low-voltage or
a medium-voltage network
[SOURCE: IEC 60050-617:2017, 617-04-20]

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IEC TR 62898-4:2023 © IEC 2023 – 9 –
3.1.3
distributed energy resource management system
DERMS
system which, on behalf of other interested systems, manages the communications and control
of individual distributed energy resources (DER), and can do this with a variety of field message
protocols, and aggregates this information and communicates with other utility systems, such
as a distribution management system (DMS)
3.1.4
distributed generation
DG
generation of electric energy by multiple sources which are connected to the power distribution
system
[SOURCE: IEC 60050-617:2009, 617-04-09, modified – The preferred terms "embedded
generation" and "dispersed generation" have been omitted.]
3.1.5
distribution management system
DMS
integration of business processes, hardware, software, and telecommunications equipment that
provide effective tools to manage the operational business processes related to network
management, outage management, power quality and other supporting operational practices
[SOURCE: IEC TS 61968-2:2011, 2.88]
3.1.6
electrical energy management system
EEMS
system monitoring, operating, controlling and managing energy resources and loads of the
installations
Note 1 to entry: This equipment can be stand-alone or integrated in other larger equipment such as a home and
building electronic system.
[SOURCE: IEC 60364-8-1:2019, 3.2.1, modified – Note 1 to entry has been added.]
3.1.7
electrical energy storage
EES
installation able to absorb electrical energy, to store it for a certain amount of time and to
release electrical energy during which energy conversion processes can be included
EXAMPLE A device that absorbs AC electrical energy to produce hydrogen by electrolysis, stores the hydrogen,
and uses that gas to produce AC electrical energy is an electrical energy storage.
Note 1 to entry: The term "electrical energy storage" may also be used to indicate the activity that an apparatus,
described in the definition, carries out when performing its own functionality.
Note 2 to entry: The term "electrical energy storage" should not be used to designate a grid-connected installation;
electrical energy storage system (3.1.8) is the appropriate term.

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– 10 – IEC TR 62898-4:2023 © IEC 2023
3.1.8
electrical energy storage system
EES system
EESS
installation with defined electrical boundaries, comprising at least one electrical energy storage,
which extracts electrical energy from an electric power system, stores this energy internally in
some manner and injects electrical energy into an electric power system and which includes
civil engineering works, energy conversion equipment and related ancillary equipment
Note 1 to entry: The EES system is controlled and coordinated to provide services to the electric power system
operators or to the electric power system users.
Note 2 to entry: In some cases, an EES system may require an additional energy source (non-electrical) during its
discharge, providing more energy to the electric power system than the energy it stored. Compressed air energy
storage is a typical example where additional thermal energy is required.
3.1.9
electric power system
EPS
composite, comprised of one or more generating sources, and connecting transmission and
distribution facilities, operated to supply electric energy
Note 1 to entry: A specific electric power system includes all installations and plant, within defined bounds, provided
for the purpose of generating, transmitting and distributing electric energy.
[SOURCE: IEC 60050-692:2017, 692-01-02]
3.1.10
isolated microgrid
group of interconnected loads and distributed energy resources forming a local electric power
system at distribution voltage levels not currently capable of being connected to a wider electric
power system
Note 1 to entry: Isolated microgrids are usually designed for geographical islands or for rural electrification.
Note 2 to entry: The definition includes a modification with respect to the IEV 617-04-23 to consider the fact that in
the future, an isolated microgrid may be connected to an electric power system thanks to grid extension (this feature
is explored further in this document).
[SOURCE: IEC 60050-617:2017, 617-04-23:2017, modified – In the definition, "with defined
electrical boundaries" has been deleted, and "that cannot be connected" has been replaced
with "not currently capable of being connected".]
3.1.11
microgrid
group of interconnected loads and distributed energy resources with defined electrical
boundaries forming a local electric power system at distribution voltage levels, that acts as a
single controllable entity and is able to operate in either grid-connected or island mode
Note 1 to entry: This definition covers both (utility) distribution microgrids and (customer owned) facility microgrids.
[SOURCE: IEC 60050-617:2017, 617-04-22]
3.1.12
prosumer’s electrical installation
PEI
electrical installation connected to a public distribution network or not able to operate with one
or both of local power supplies and local storage units, and that monitors and controls the
energy from the connected sources delivering it to one or more of loads, local storage units,
and public distribution network

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IEC TR 62898-4:2023 © IEC 2023 – 11 –
3.1.13
virtual power plant
VPP
group of distributed energy resources which combine to function as a dispatchable unit
Note 1 to entry: A virtual power plant can be used for the purpose of participating in the electricity market or
aggregating ancillary services.
[SOURCE: IEC 60050-617:2017, 617-04-27]
3.2 Abbreviated terms
BUC business use cases
CIM common information model
DC direct current
DER distributed energy resource(s)
DERMS distributed energy resources management system
DG distributed generation
DMS distribution management system
DSO distribution system operator
EEMS electrical energy management system
EES energy storage system
EESS electrical energy storage system
EMS energy management system
EV electric vehicle
EPS electric power system
FACTS flexible alternating current transmission system
HV high voltage
HVDC high voltage direct current
IEC International Electrotechnical Commission
LV low voltage
MV medium voltage
POC point of connection
PEI prosumer’s electrical installation
PQ power quality
REP retail energy provider
SCADA supervisory control and data acquisition
SMU system management unit
SUC system use cases
SyC system committee
TSO transmission system operator
1
Unified Modeling Language™
UML®
VPP virtual power plant

___________
1
 UML® and Unified Modeling Language™ are trademarks of The Object Management Group. This information is
given for the convenience of users of this document and does not constitute an endorsement by IEC of the product
named.

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4 Overview of the document
In line with the methodology specified in IEC SRD 62913-1, this document describes business
use cases (high-level use cases covering the main typical usage of microgrids) and details
some of them.
Like any business use cases, these use cases attempt to be agno
...