IEC TS 62898-1:2017/AMD1:2023

IEC TS 62898-1 ®
Edition 1.0 2023-08
TECHNICAL
SPECIFICATION
colour
inside
AMENDMENT 1
Microgrids –
Part 1: Guidelines for microgrid projects planning and specification

IEC TS 62898-1:2017-05/AMD1:2023-08(en)

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IEC TS 62898-1 ®
Edition 1.0 2023-08
TECHNICAL
SPECIFICATION
colour
inside
AMENDMENT 1
Microgrids –
Part 1: Guidelines for microgrid projects planning and specification

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01  ISBN 978-2-8322-7435-4

– 2 – IEC TS 62898-1:2017/AMD1:2023
© IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MICROGRIDS –
Part 1: Guidelines for microgrid projects planning and specification

AMENDMENT 1
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.
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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 document may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
Amendment 1 to IEC 62898-1:2017 has been prepared by subcommittee 8B: Decentralized
electrical energy systems, of IEC technical committee 8: System aspects of electrical energy
supply.
The text of this Amendment is based on the following documents:
Draft Report on voting
8B/165/DTS 8B/179/RVDTS
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 Amendment is English.

© 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/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 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.

___________
INTRODUCTION
Replace the second paragraph, beginning with "This part of IEC 62898 defines the guidelines
for the general planning and design of microgrids"with the following new text.
This part of IEC 62898 defines the guidelines for the general planning and design of microgrids,
IEC TS 62898-2 defines the general technical requirements for operation and control of
microgrids, IEC TS 62898-3-1 defines the technical requirements for protection and dynamic
control of microgrids, IEC TS 62898-3-2 defines the technical requirements for energy
management systems of microgrids, IEC TS 62898-3-3 defines the technical requirements for
self-regulation loads of microgrids, and IEC TS 62898-3-4 defines the technical requirements
for microgrid monitoring and control systems. IEC TC8/SC8B/JWG1 is responsible for the
development of these TS.
3 Terms and definitions
3.5
earth
ground
Replace the existing definition and source with the following:
part of the earth that is in electric contact with an earth electrode and that has an electric
potential not necessarily equal to zero
[SOURCE: IEC 60050-195:2021, 195-01-03, modified – The adjective "local" has been removed
from the term.]
– 4 – IEC TS 62898-1:2017/AMD1:2023
© IEC 2023
3.6
earthing arrangement
grounding arrangement
Replace the existing definition and source with the following:
all electrical means involved in the earthing of a system, installation or equipment
Note 1 to entry: Electric connection and devices used for earthing are examples of electrical means.
[SOURCE: IEC 60050-195:2021, 195-02-20]
3.7
earthing conductor
grounding conductor
Replace the existing definition and source with the following:
conductor forming a conductive path between a conductive part and an earth electrode
[SOURCE: IEC 60050-195:2021, 195-02-03]
3.8
electromagnetic compatibility
EMC
Replace the existing source with the following:
[SOURCE: IEC 60050-161:2018, 161-01-07]
3.9
distributed energy resources
DER
Replace the existing definition with the following:
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]

3.15
island
Replace the existing definition and source with the following.

part of an electric power system that is electrically disconnected from the remainder of the
interconnected electric power system but remains energized from local electric power sources
Note 1 to entry: An electric island can be either the result of the action of automatic protections or the result of a
deliberate action.
Note 2 to entry: An electric island can be stable or unstable.
Note 3 to entry: Inside the electric island, generators and loads can be any combination of customer-owned and
utility-owned units.
[SOURCE: IEC 60050-692:2017, 692-02-11, modified – The term "electric" has been removed
from the term., Note 3 to entry has been added.]

© IEC 2023
3.16
isolated microgrid
Replace the existing definition with the following:
group of interconnected loads and distributed energy resources with defined electrical
boundaries forming a local electric power system at distribution voltage levels, that cannot be
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: A microgrid capable of being connected to a wider electric power system is also called non-isolated
microgrid or embedded microgrid.
[SOURCE: IEC 60050-617:2017, 617-04-23, modified – Note 2 to entry has been added.]
3.22
microgrid
Replace the existing definition and notes to entry with the following:
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 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]

5 Purpose and application of microgrids
5.2 Application of non-isolated microgrids
Replace the last sentence of the last paragraph, beginning with "Certain equipment to improve
power quality and reliability" with the following new text:
Certain equipment to improve power quality and reliability, for example energy storage systems,
harmonics filters, and reactive power compensators should be installed in the microgrid if
needed.
5.3 Application of isolated microgrids
Replace the last sentence of the first paragraph, beginning with "Therefore, such a microgrid"
with the following new text:
Therefore, such a microgrid should contain sufficient energy storage capacity and dispatchable
generation capacity.
13 Technical requirements for control, protection and communication systems
13.2 Protection relays and automatic protection devices
13.2.4 Load shedding in a microgrid
Delete, in the first sentence, the redundant word "voltage" in front of the word "protection".

– 6 – IEC TS 62898-1:2017/AMD1:2023
© IEC 2023
14 Evaluation of microgrid projects
14.3 Economic benefits
Add, after the first paragraph, the following new text:
The calculation of the economic benefits should also consider the net present value, where the
cash flow during the life time is discounted back to its present value.
N
R
t
Net PresentValue= (1)
∑
t
1+i
t=0( )
where
t is the time step during the lifetime;
th
R is the cash flow during t time step;
t
i is the interest rate.
The costs of power plants are assessed according to their variable and fixed costs. The
simplified linear equation given in Formula (1) shows the cost function:
K=K+=K K+Tk× (2)
sum fix,P var,P fix,P a var,P
where
K are the total costs;
sum
are the total fixed costs for the power capacity component;
K
fix,P
K are the total variable costs for the power capacity component;
var,P
k are the variable costs for the power capacity component in monetary unit per kWh;
var,P
T are the yearly full load hours.
a
For energy storages, a similar formula (see Formula (3) may be used to assess the leveliz
...