IEC TS 62898-3-4:2023
(Main)Microgrids - Part 3-4: Technical requirements - Microgrid monitoring and control systems
Microgrids - Part 3-4: Technical requirements - Microgrid monitoring and control systems
IEC TS 62898-3-4:2023 provides technical requirements for the monitoring and control of microgrids. This document applies to non-isolated or isolated microgrids integrated with distributed energy resources. This document describes the specific recommendations for low-voltage (LV) and medium-voltage (MV) microgrids.
This document focuses on standardization of the architecture, functions, and operation of microgrid monitoring and control systems (MMCS). It teases out the general functions of MMCS and provides technical requirements for MMCS. This document includes the following aspects of MMCS:
• system architecture,
• information exchange with other devices/functions in microgrid,
• performance requirement,
• main function descriptions.
General Information
Standards Content (Sample)
IEC TS 62898-3-4 ®
Edition 1.0 2023-08
TECHNICAL
SPECIFICATION
Microgrids –
Part 3-4: Technical requirements – Microgrid monitoring and control systems
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IEC TS 62898-3-4 ®
Edition 1.0 2023-08
TECHNICAL
SPECIFICATION
Microgrids –
Part 3-4: Technical requirements – Microgrid monitoring and control systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01 ISBN 978-2-8322-7438-5
– 2 – IEC TS 62898-3-4:2023 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 9
3 Terms, definitions and abbreviated terms . 10
3.1 Terms and definitions . 10
3.2 Abbreviated terms . 12
4 Overview . 12
4.1 General . 12
4.2 System architecture . 13
4.2.1 Stand-alone MMCS . 13
4.2.2 Integrated MMCS . 14
4.3 Hardware and software architectures . 14
4.3.1 Hardware . 14
4.3.2 Software . 15
4.3.3 Database . 15
4.4 Communication and cyber security . 15
4.4.1 Communication . 15
4.4.2 Cyber security . 16
5 Functional requirements . 17
5.1 Data acquisition and processing . 17
5.1.1 Data acquisition . 17
5.1.2 Data processing . 17
5.2 Database management . 18
5.3 Human-machine interface . 18
5.4 Anti-maloperation locking and alarm . 19
5.5 Time synchronization . 20
5.6 Local power quality control . 20
5.7 Frequency/voltage regulation during steady state operation of isolated
microgrid . 20
5.8 Sequence of operations . 21
5.9 Control of device switching . 21
5.10 Operating mode transition . 21
5.10.1 General . 21
5.10.2 Transition from island mode to grid-connected mode . 22
5.10.3 Transition from grid-connected mode to island mode . 22
5.11 Active and reactive power control . 22
5.11.1 General . 22
5.11.2 Active power control . 22
5.11.3 Reactive power control and voltage control . 23
5.12 Islanding detection . 23
5.13 Black start. 24
Annex A (informative) Example of collected information of MMCS . 25
A.1 Microgrid operating data . 25
A.1.1 Status data . 25
A.1.2 Measurement data . 25
A.2 Microgrid equipment operating status data . 26
A.2.1 Primary equipment operating status data . 26
A.2.2 Secondary equipment operating status data . 26
A.2.3 Auxiliary equipment operating status data . 26
A.3 Microgrid forecast data . 27
A.4 Distributed energy planning data . 27
Annex B (informative) Examples of actual microgrid applications and the associated
functions of MMCS . 28
B.1 Application CN1: MMCS of microgrid with photovoltaic and battery
compacted with monitoring and control system of intelligent office park . 28
B.1.1 General . 28
B.1.2 System structure of MMCS . 29
B.1.3 Main functions of MMCS . 29
B.1.4 Applications . 30
B.2 Application CN2: MMCS of MV small hydropower microgrid for solving power
supply problems in remote areas . 30
B.2.1 General . 30
B.2.2 System structure of MMCS . 31
B.2.3 Main functions of MMCS . 32
B.2.4 Applications . 34
B.3 Application JP1: Power stabilization with combining high-speed ΔF and ΔP
suppression control utilizing storage batteries connected to thermal
generation: the IKI island demonstration project from Japan . 36
B.3.1 General . 36
B.3.2 Purpose . 37
B.3.3 Main functions of MMCS . 37
B.3.4 Applications . 38
Bibliography . 40
Figure 1 – Functional mapping for operation and control of microgrids . 13
Figure 2 – Structure of MMCS . 14
Figure 3 – Typical three-layer communication for structure 1 . 16
Figure 4 – Typical two-layer communication for structure 2 . 16
Figure B.1 – Primary structure of Chengchuang microgrid. 28
Figure B.2 – System structure of MMCS . 29
Figure B.3 – The main single line diagram of the small hydropower microgrid . 31
Figure B.4 – The main structure of MMCS. 32
Figure B.5 – Daily voltage curve along the common line and Fengshan line before the
implementation of microgrid in flooding period and heavy load . 34
Figure B.6 – Daily voltage curve along the common line and Fengshan line after the
implementation of microgrid . 35
Figure B.7 – Daily voltage curve along the common line and Fengshan line before the
implementation of microgrid . 35
Figure B.8 – Daily voltage curve along the common line and Fengshan line after the
implementation of microgrid . 36
Figure B.9 – Overview of Iki Island power system and battery . 37
Figure B.10 – Overview of control flow . 38
Figure B.11 – Example of stable frequency due to storage battery charge / discharge . 39
– 4 – IEC TS 62898-3-4:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MICROGRIDS
Part 3-4: Technical requirements –
Microgrid monitoring and control systems
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
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preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
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shall not be held responsible for identifying any or all such patent rights.
IEC TS 62898-3-4 has been prepared by subcommittee 8B: Decentralized electrical energy
systems, of IEC technical committee TC 8: System aspects of electrical energy supply. It is a
Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
8B/154/DTS 8B/178/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 Technical Specification is English.
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.
– 6 – IEC TS 62898-3-4:2023 © IEC 2023
INTRODUCTION
Microgrids can serve different purposes depending on the primary objectives of their
applications. They are usually seen as means to manage reliability of supply and local
optimization of energy supply by controlling distributed energy resources (DER). Microgrids
also present a way to provide electricity supply in remote areas and to use clean and renewable
energy as a systemic approach for rural electrification.
At present, there are many types of microgrid, often composed of distributed generation, battery
energy storage, load, and other equipment. To achieve the effective integration and cooperative
operation of the above equipment, a set of computer systems is often required, which is
normally named as microgrid monitoring and control system. With the popularization of
microgrids, the industry urgently needs a standard to specify the system architecture,
component composition and functional requirements of microgrid monitoring and control system.
There are also various types of microgrid monitoring and control systems. For large scale
(installed power > 100 kW) microgrid, its monitoring system and control system is more complex,
usually using independent servers, workstations, remote terminal units, and others. Its
communication protocol and data model can be based on the IEC 61850 series, and the system
consists of a master station level and a local equipment level. For small-scale microgrids below
100 kW level, such as household microgrids with photovoltaic power generation and battery
storage, it is relatively expensive to configure a complex microgrid monitoring and control
system. At this time, the microgrid will generally adopt lightweight and cheap technical solutions,
and the microgrid monitoring, control and energy management function will often be combined
into a single device. Sometimes, for the small microgrid in remote mountainous areas, microgrid
monitoring and control system based on the Internet of Things and cloud computing architecture
is often used to realize the local autonomy and remote monitoring of the micro grid.
IEC TS 62898 series is intended to provide general guidelines and technical requirements for
microgrid projects.
IEC TS 62898-1 mainly covers the following issues:
• determination of microgrid purposes and application,
• preliminary study necessary for microgrid planning, including resource analysis, load
forecast, DER planning and power system planning,
• principles of microgrid technical requirements that should be specified during planning
stage,
• microgrid evaluation to select an optimal microgrid planning scheme.
IEC TS 62898-2 mainly covers the following issues:
• operation requirements and control targets of microgrids under various operation modes,
• the basic control strategies and methods under various operation modes,
• the requirements of electrical energy storage (EES), relay protection, monitoring and
communication under various operation modes,
• power quality.
IEC TS 62898-3-XX subseries technical specifications deal with the technical requirements of
microgrids.
IEC TS 62898-3-1 mainly covers the following issues:
• requirements for microgrid protection,
• protection systems for microgrids,
• dynamic control for transient and dynamic disturbances in microgrids.
IEC TS 62898-3-2 covers the energy management system of microgrids.
IEC TS 62898-3-3 covers the self-regulation of dispatchable loads of microgrids.
This document covers microgrid monitoring and control systems (MMCS). It aims to provide
requirements to address state monitoring and operation control problems in microgrids.
—————————
Under preparation.
– 8 – IEC TS 62898-3-4:2023 © IEC 2023
MICROGRIDS
Part 3-4: Technical requirements –
Microgrid monitoring and control systems
1 Scope
The purpose of this part of IEC 62898 is to provide technical requirements for the monitoring
and control of microgrids. This document applies to non-isolated or isolated microgrids
integrated with distributed energy resources. This document describes the specific
recommendations for low-voltage (LV) and medium-voltage (MV) microgrids.
This document focuses on standardization of the architecture, functions, and operation of
microgrid monitoring and control systems (MMCS). It teases out the general functions of MMCS
and provides technical requirements for MMCS. This document includes the following aspects
of MMCS:
• system architecture,
• information exchange with other devices/functions in microgrid,
• performance requirement,
• main function descriptions.
The system architecture for MMCS:
• For a large scale (installed power > 100 kW) microgrid, microgrid energy management
system (MEMS) and MMCS are normally separated. MMCS normally contains data servers,
application servers, workstations, routers, information safety devices, SCADA,
communication system, distributed generation controller, microgrid central controller, load
controller, grid connection interface device and other ancillary equipment.
• For a small user-side microgrid (normally less than 100 kW), MEMS and MMCS are normally
merged into one embedded device with system on chip, which is named as microgrid
controller.
Main functions of MMCS:
• Data acquisition and processing, including collecting real-time data from the distributed
generation, load, switches, transformers and reactive power compensation devices, and
calculation and analysis of the acquired data.
• Database management, including maintaining, synchronizing, backing up, restoring the
acquired data, and providing the data interface with other internal and external applications.
• Human-machine interface, including the real-time monitor screen and interface which is
capable of remote control, mode switching, manual data entry, etc.
• Anti-maloperation locking and alarm, to lock the maloperation based on the predefined rule
and logic.
• Time synchronization, including receiving the time synchronization signal from Global
Navigation Satellite System (GNSS) or network time protocol (NTP) and synchronizing the
time of each device within the microgrid.
• Local power quality evaluation and control the ability to collect information of out-of-limit
voltage, power factor, harmonic, etc. and carry out control to improve power quality
accordingly.
• Frequency/voltage regulation during steady state operation of an isolated microgrid to
provide voltage and frequency inside an accepted operation range.
• Sequence of operations, or steady transition from power-off to start-up and from start-up to
power-off.
• Switch control of devices within microgrids, including turning on and off loads, generation
units, transformers, reactive power compensation devices, etc.
• Islanding detection, including real-time detection on power outage of the upstream
distribution system.
• Operation mode transition, including transition from grid-connected mode to island mode
and transition from island mode to grid-connected mode.
• Active and reactive power control, including load shedding (if required), load sharing and
controlling the active and reactive power in real time according to the MEMS or manual
command.
• Black start, the ability to initiate power sources and loads to ensure the microgrid can initiate
operation from a non-energized state.
• Interface with the protection system or earthing system when adaptations are required
according to the microgrid operating modes.
2 Normative references
The following documents are referred to in the text in such a way that some or all 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 60870-5-101, Telecontrol equipment and systems – Part 5-101: Transmission protocols –
Companion standard for basic telecontrol tasks
IEC 60870-5-104, Telecontrol equipment and systems – Part 5-104: Transmission protocols –
Network access for IEC 60870-5-101 using standard transport profiles
IEC 61850 (all parts), Communication networks and systems for power utility automation
IEC 62443 (all parts), Security for industrial automation and control systems
IEC 62586-1, Power quality measurement in power supply systems – Part 1: Power quality
instruments (PQI)
IEC TS 62898-1, Microgrids – Part 1: Guidelines for microgrid projects planning and
specification
IEC TS 62898-2, Microgrids – Part 2: Guidelines for operation
IEC TS 62898-3-1, Microgrids – Part 3-1: Technical requirements – Protection and dynamic
control
IEC TS 62898-3-2:— , Microgrids – Part 3-2: Technical requirements – Energy management
systems
IEC TS 62898-3-3, Microgrids − Part 3-3: Technical requirements − Self-regulation of
dispatchable loads
—————————
Under preparation. Stage at the time of preparation: IEC DTS 62898-3-2:2023.
– 10 – IEC TS 62898-3-4:2023 © IEC 2023
IEEE Std 1815-2012, IEEE Standard for Electric Power Systems Communications-Distributed
Network Protocol (DNP3)
IRIG-B Standards Documentation (IRIG.ORG) [viewed 2023-08-07]
Modbus Standards Documentation (Modbus.org) [viewed 2023-08-07]
NTP Standards Documentation (ntp.org) [viewed 2023-08-07]
OASIS Standards Documentation, MQTT Version 5.0 (oasis-open.org) [viewed 2023-07-24]
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions 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
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 island mode, no matter if it is
standalone or grid-connected
Note 1 to entry: This definition covers both (utility) distribution microgrids and (customer owned) facility microgrids.
[SOURCE: IEC 60050-617:2017, 617-04-22, modified – "in either grid-connected or island
mode" has been changed to " in island mode, no matter if it is standalone or grid-connected".]
3.1.2
microgrid monitoring and control systems
MMCS
computer or PLC based system performing real time monitoring and control of microgrid
Note 1 to entry: In large grid or large microgrid, such a system is also designated by PMS (Power Monitoring
System).
3.1.3
microgrid energy management system
MEMS
system operating and controlling energy resources and loads of the microgrid
[SOURCE: IEC 60050-617:2018, 617-04-25]
3.1.4
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]
3.1.5
renewable energy resource
RES
non-fossil energy resource such as wind, solar, hydropower, biomass, geothermal, etc
3.1.6
low voltage
LV
set of voltage levels used for the distribution of electricity and whose upper limit is generally
accepted to be 1 000 V for alternating current
[SOURCE: IEC 60050-601:1985, 601-01-26]
3.1.7
medium voltage
MV
any set of voltage levels lying between low and high voltage
Note 1 to entry: The boundaries between medium- and high-voltage levels overlap and depend on local
circumstances and history or common usage. Nevertheless, the band 30 kV to 100 kV frequently contains the
accepted boundary.
[SOURCE: IEC 60050-601:1985, 601-01-28]
3.1.8
generic object-oriented substation event
GOOSE
mechanism used in the IEC 61850 series to meet the requirements of substation automation
system fast communication
3.1.9
inter-range instrumentation group-B
IRIG-B code
time information transmission system that loads the time synchronization signal and the time
code information such as second, minute, hour and day into the signal carrier with a frequency
of 1 kHz
3.1.10
network time protocol
NTP
time synchronization protocol that serves computer clocks via the network
3.1.11
power system stability
capability of a power system to regain a steady state, characterized by the synchronous
operation of the generators after a disturbance due, for example, to variation of power or
impedance
[SOURCE: IEC 60050-603:1986, 603-03-01]
3.1.12
point of connection
POC
reference point on the electric power system where the user’s electrical facility is connected
[SOURCE: IEC 60050-617:2009, 617-04-01]
– 12 – IEC TS 62898-3-4:2023 © IEC 2023
3.1.13
power conversion system
PCS
device that can control the charging and discharging process of a battery storage system, and
carry out AC-DC conversion
3.1.14
state of charge
SOC
available capacity in a battery pack or system expressed as a percentage of rated capacity
[SOURCE: ISO 12405-4:2018, 3.20]
3.2 Abbreviated terms
DER Distributed Energy Resource
DSO Distribution System Operator
EPS Electrical Power System
ESS Energy Storage System
GOOSE Generic Object-Oriented Substation Event
GIS Geographic Information System
GUI Graphic User Interface
GNSS Global Navigation Satellite System
IRIG-B Inter-Range Instrumentation Group-B
LV Low Voltage
MV Medium Voltage
MMCS Microgrid Monitoring and Control System
MEMS Microgrid Energy Management System
MQTT Message Queuing Telemetry Transport
NTP Network Time Protocol
POC Point of Connection
PLC Programmable Logic Controller
PCS Power Conversion System
PQI Power Quality Instrument
RES Renewable Energy Source
SOC State of Charge
UPS Uninterruptible Power Supply
4 Overview
4.1 General
The operation control system of a microgrid can be divided into three layers according to the
time scale, namely the energy management layer, the monitoring and control layer and the
protection and dynamic control layer.
MMCS mainly concerns the monitoring and control layer in the microgrid system.
Functions listed in Figure 1 are project dependent. Some functions can be omitted depending
on the scale or application of the microgrid. However, MMCS shall at least perform data
acquisition and processing, database management, maloperation locking, switch control of
devices, active and reactive power control of devices. In Annex B, MMCS functions are
performed or detailed in some actual application cases.
Figure 1 – Functional mapping for operation and control of microgrids
4.2 System architecture
4.2.1 Stand-alone MMCS
For a large scale (installed power > 100 kW) microgrid, MMCS normally exist as a stand-alone
system, which is intended to handle only the monitoring and control layer. It is configured to
have the functions involving time scales in the range of seconds to minutes, such as data
acquisition and processing, active and reactive power control, frequency/voltage regulation
during normal operation of isolated microgrid, islanding detection and mode switching.
MMCS can adopt a hierarchical or distributed architecture shown in Figure 2, such as master
station layer (or central control layer) and local control layer. The layers are connected by a
communication network. Distributed architecture has the advantage that the failure or
disconnection of one device in the system does not affect the normal operation of the other part
of the system. The system can also stay operational when an equipment or the network at the
central control level fails.
MMCS normally contains the whole set or parts of the following: SCADA, communication
system, distributed generation controller, microgrid central controller, load controller, grid-
interfacing device, cyber security protection devices and other secondary equipment. The above
equipment can be sophisticated or simplified according to the scale and functional requirements
of the microgrid.
For a large scale (installed power > 100 kW) microgrid, MEMS and MMCS are normally
separated. MMCS can exchange data with MEMS in the microgrid. MMCS monitors the data of
devices, assuring the parameters to stay within a pre-defined operating range, and sends
information to the MEMS. MEMS gives operational orders to MMCS and MMCS executes the
orders by controlling switches, distributed energy resources and loads in the microgrid. If the
MEMS control orders according to economic criteria would violate power system stability
constraints, MMCS should make a corrective control to ensure the power system stability.
– 14 – IEC TS 62898-3-4:2023 © IEC 2023
Figure 2 – Structure of MMCS
4.2.2 Integrated MMCS
For a small user-side microgrid (installed power < 100 kW), MEMS and MMCS are normally
merged into one embedded device with system on chip, which is named as microgrid controller.
Microgrid monitoring and control module as a system integrated into a microgrid controller is
intended to handle the second layer of operation and control system. It is configured to have
the functions with short time scales (minute, second), such as data acquisition and processing,
active and reactive power control, frequency/voltage regulation during normal operation of
isolated microgrid, islanding detection and mode switching.
The integrated MMCS shall have a communication module, a human-machine interface module,
a data storage module, a power module, a calculation and processing module.
4.3 Hardware and software architectures
4.3.1 Hardware
4.3.1.1 General
MMCS could be a stand-alone system or integrated system.
4.3.1.2 Stand-alone system
For a stand-alone system, MMCS should include the front-end processor, data server,
application server, workstation, Ethernet switch, routers, sensors, meters, and other equipment.
The number of servers and workstations can be adjusted according to the scale of microgrid
and requirement of calculation.
MMCS shall configure firewalls, isolation devices, or other cyber security equipment. For
additional information on cyber security requirement, see IEC 62443-4-2.
4.3.1.3 Integrated system
For an integrated module, MMCS should be implemented as an integrated control module, i.e.
based on a PLC (Programmable Logic Controller).
4.3.2 Software
MMCS software shall include the operating system, supporting platform and application
software.
The supporting platform software should be capable of performing functions such as data
acquisition management, database management, network communication management,
graphics management, report management, authority management, alarm management,
calculation, statistics, etc.
The application software should adopt a modular structure with a fast response speed, flexible
expandability, and error detection capability. When the application fails, MMCS shall prompt an
alarm message, and the operation of other applications shall not be affected.
4.3.3 Database
For large microgrids, MMCS should configure a real time database and a historical database.
The historical data shall be saved periodically, the data storage period and storage resolution
should depend on the scale of the system.
4.4 Communication and cyber security
4.4.1 Communication
The microgrid communication involves external communication and internal communication.
The external communication is applied for information exchange between the microgrid and the
upstream grid dispatching system called "dispatch centre" and the internal communication is
applied for information exchange among MEMS, MMCS, DER and/or other internal equipment
of the microgrid. In the case of an isolated microgrid, i.e., not connected to an upstream large
grid, it is not required to establish a communication link with a dispatch center (dotted point
lines in Figure 3 and Figure 4), but a communication link with an upper control system or cloud
functions could be required.
The communication protocols shall be defined according to the interoperability requirements.
For example, the communication protocol can be the IEC 61850 series, IEC 60870-5-101 or
IEC 60870-5-104.
For internal communication, the number of layers depends on the structure of the MMCS.
Internal communication for structure 1: Stand-alone MMCS
Under a three-layer architecture, the protocols of IEC 60870-5-101, IEC 60870-5-104, DNP3
(Distributed Network Protocol, IEEE Std 1815), IEC 61850 series, Modbus (Modbus
specification shall conform to terms specified in Modbus.org or IEC 61158 series/IEC 61784
series), MQTT (MQTT specification shall conform to terms specified in oasis-open.org), etc.
can be applied between MMCS and MEMS, and the IEC 61850 series, Modbus and other
protocols can be applied between MMCS and the DER and internal equipment of microgrid. The
communication medium used for the microgrid can be optical fibre, twisted pair, wireless, etc.
according to specific application conditions.
– 16 – IEC TS 62898-3-4:2023 © IEC 2023
Figure 3 – Typical three-layer communication for structure 1
Internal communication for structure 2: Integrated MMCS
Under a two-layer architecture, the protocols of the IEC 61850 series, Modbus and other
protocols can be applied between MMCS and the DER and internal equipment of the microgrid.
The communication medium used for the microgrid can be optical fibre, twisted pair, wireless,
etc. according to specific application conditions.
Figure 4 – Typical two-layer communication for structure 2
4.4.2 Cyber security
The cyber security strategy of MMCS shall be aligned with the IEC 62443 series, which defines
security levels and associated requirements for Industrial Automation and Control Systems
(IACS).
The IEC 62443 series defines four different security levels (SL1 to SL4), with specific
requirements applicable to system level specified in IEC 62443-3-3 and component level
specified in IEC 62443-4-2. The required level remains specific to each microgrid application
and its required security profile. The manufacturer or system provider shall declare the security
level of the MEMS and its components, as defined in the IEC 62443 series.
Cyber security functions of MMCS should be shared with MEMS (see IEC 62898-3-2), and the
declared security level can be common.
5 Functional requirements
5.1 Data acquisition and processing
5.1.1 Data acquisition
MMCS shall be able to collect analog and digital real-time data. Data could be collected from
MEMS, microgrid central controller, DER, loads, power conversion system, battery
management system, communication protocol converter, etc.
MMCS shall be able to collect data regarding the scale and DER of the microgrid. The data
include but are not limited to the following:
• busbar voltage/frequency, current, and power for all the microgrid,
• switch position of power distribution units for a large scale microgrid,
• DC power/current/voltage, AC power/generation, etc. of renewable energy resources like
photovoltaics or wind turbines,
• forward/reverse active power generation, forward/reverse reactive power generation of
Power Meter Devices (PMD) for microgrid with respective energy resources or PMD,
• power quality for the microgrid with power quality instrument,
• internal temperature, DC power/current/voltage, and AC power/current/voltage from power
conversion system for the microgrid with ESS,
• battery group terminal voltage/current/SOC, single battery voltage/current/SOC, and
temperature from battery management system for the microgrid with ESS.
Annex A gives an example of information to be collected by the MMCS. For additional
information on the data models, see IEC TR 61850-90-23 and CIM of IEC 61970 series.
5.1.2 Data processing
MMCS shall be capable of calculating and analysing the collected data. Data processing could
include but is not limited to the following functions:
• data source selection and automatic calculation: includes statistical analysis of real-time
maximum, minimum, average, and total of specified data by minute, hour, day, week, month,
quarter, year, or customized period,
• logical assessment of status signals of breakers and switches,
• counting the number of position changes of specific equipment,
• statistical analysis of remote-control
...
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