Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises
Introduction. In conditions of unstable external power supply, industrial enterprises with critical electrical technological processes require reliable backup power supply. Traditional approaches to power supply backup, based on separate diesel generators or uninterruptible power supply systems, do...
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| Дата: | 2026 |
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| Мова: | Англійська Українська |
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National Technical University "Kharkiv Polytechnic Institute" and Аnatolii Pidhornyi Institute of Power Machines and Systems of NAS of Ukraine
2026
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Electrical Engineering & Electromechanics| _version_ | 1869562791540555776 |
|---|---|
| author | Shcherba, A. A. Podoltsev, O. D. Suprunovska, N. I. Belyanin, R. V. |
| author_facet | Shcherba, A. A. Podoltsev, O. D. Suprunovska, N. I. Belyanin, R. V. |
| author_institution_txt_mv | [
{
"author": "A. A. Shcherba",
"institution": "Інститут електродинаміки НАН України"
},
{
"author": "O. D. Podoltsev",
"institution": "Інститут електродинаміки НАН України"
},
{
"author": "N. I. Suprunovska",
"institution": "Інститут електродинаміки НАН України"
},
{
"author": "R. V. Belyanin",
"institution": "ПАТ «ЗАВОД ПІВДЕНКАБЕЛЬ»"
}
] |
| author_sort | Shcherba, A. A. |
| baseUrl_str | http://eie.khpi.edu.ua/oai |
| collection | OJS |
| datestamp_date | 2026-07-01T21:42:56Z |
| description | Introduction. In conditions of unstable external power supply, industrial enterprises with critical electrical technological processes require reliable backup power supply. Traditional approaches to power supply backup, based on separate diesel generators or uninterruptible power supply systems, do not provide the required quality and continuity of power supply during long-term emergency outages from the national power grid. Problem. Existing theoretical principles for building microgrids are focused mainly on single-phase distribution networks of low power and do not take into account the features of powerful three-phase industrial microgrids. In particular, the problems of ensuring system stability under conditions of low inertia (absence of rotating masses of generators) and implementing «seamless» transitions between the parallel operation mode with the external grid and the autonomous («island») mode, as well as effective local power balancing taking into account the priority of consumers, remain unresolved. Goal. Development of the principles for building powerful three-phase microgrids capable of providing uninterrupted and high-quality power supply to industrial enterprises with critical energy consumers in conditions of unstable general power supply. Methodology. The study is based on a systematic analysis of international standards and modern publications in the field of microgrids, hierarchical control theory, methods of computer modeling of microgrid modes, as well as on the generalization of experience in designing, installing and long-term (more than one year) experimental and industrial operation of a microgrid with a capacity of more than 1.5 MVA at a real industrial enterprise in Ukraine. Results. Six basic principles for building powerful industrial microgrids have been developed and systematized. The effectiveness of these principles is confirmed by the successful operation of the designed microgrid, which includes a cogeneration unit (up to 1.5 MW), a diesel generator (up to 825 kW), a solar station (72.5 kW), four specialized uninterruptible power supplies with a total capacity of up to 1.95 MW, and an electricity storage unit with a capacity of up to 10 MWh. Scientific novelty. For the first time, the principles for building powerful three-phase industrial microgrids has been developed as a system of six interconnected principles, which, unlike existing approaches, cover the physical aspects of stabilization, system aspects of control and quality aspects of electricity (reactive power compensation, load balancing). The proposed principles are intended for microgrids with a capacity of more than 1 MVA and take into account the specifics of industrial enterprises. Practical value. The proposed principles provide a methodological basis for the design and modernization of powerful industrial microgrids in Ukraine and other countries with unstable power supply. References 36, figures 3. |
| doi_str_mv | 10.20998/2074-272X.2026.4.10 |
| first_indexed | 2026-07-02T01:00:17Z |
| format | Article |
| fulltext |
74 Electrical Engineering & Electromechanics, 2026, no. 4
© A.A. Shcherba, O.D. Podoltsev, N.I. Suprunovska, R.V. Belyanin
UDC 621.311 https://doi.org/10.20998/2074-272X.2026.4.10
A.A. Shcherba, O.D. Podoltsev, N.I. Suprunovska, R.V. Belyanin
Principles of building powerful microgrids for uninterrupted power supply of industrial
enterprises
Introduction. In conditions of unstable external power supply, industrial enterprises with critical electrical technological processes require
reliable backup power supply. Traditional approaches to power supply backup, based on separate diesel generators or uninterruptible power
supply systems, do not provide the required quality and continuity of power supply during long-term emergency outages from the national
power grid. Problem. Existing theoretical principles for building microgrids are focused mainly on single-phase distribution networks of low
power and do not take into account the features of powerful three-phase industrial microgrids. In particular, the problems of ensuring system
stability under conditions of low inertia (absence of rotating masses of generators) and implementing «seamless» transitions between the
parallel operation mode with the external grid and the autonomous («island») mode, as well as effective local power balancing taking into
account the priority of consumers, remain unresolved. Goal. Development of the principles for building powerful three-phase microgrids
capable of providing uninterrupted and high-quality power supply to industrial enterprises with critical energy consumers in conditions of
unstable general power supply. Methodology. The study is based on a systematic analysis of international standards and modern publications
in the field of microgrids, hierarchical control theory, methods of computer modeling of microgrid modes, as well as on the generalization of
experience in designing, installing and long-term (more than one year) experimental and industrial operation of a microgrid with a capacity of
more than 1.5 MVA at a real industrial enterprise in Ukraine. Results. Six basic principles for building powerful industrial microgrids have
been developed and systematized. The effectiveness of these principles is confirmed by the successful operation of the designed microgrid,
which includes a cogeneration unit (up to 1.5 MW), a diesel generator (up to 825 kW), a solar station (72.5 kW), four specialized
uninterruptible power supplies with a total capacity of up to 1.95 MW, and an electricity storage unit with a capacity of up to 10 MWh.
Scientific novelty. For the first time, the principles for building powerful three-phase industrial microgrids has been developed as a system of
six interconnected principles, which, unlike existing approaches, cover the physical aspects of stabilization, system aspects of control and
quality aspects of electricity (reactive power compensation, load balancing). The proposed principles are intended for microgrids with a
capacity of more than 1 MVA and take into account the specifics of industrial enterprises. Practical value. The proposed principles provide a
methodological basis for the design and modernization of powerful industrial microgrids in Ukraine and other countries with unstable power
supply. References 36, figures 3.
Key words: powerful electric microgrid, uninterrupted power supply, local power balance, sources of electricity, electricity
storage devices.
Вступ. В умовах нестабільного зовнішнього електропостачання промислові підприємства з критично важливими
електротехнологічними процесами потребують надійного резервного електроживлення. Традиційні підходи до резервування,
засновані на окремих дизель-генераторах або системах безперервного живлення, не забезпечують необхідної якості та
безперервності електроживлення при тривалих аварійних відключеннях від загальнодержавної енергосистеми. Проблема. Існуючі
теоретичні засади проєктування мікромереж орієнтовані переважно на однофазні розподільчі мережі невеликої потужності і
не враховують особливості потужних трифазних промислових мікромереж. Зокрема, залишаються невирішеними проблеми
забезпечення стабільності системи в умовах низької інерції (відсутності обертових мас генераторів), реалізації «безшовних»
переходів між режимом паралельної роботи із зовнішньою мережею та автономним («острівним») режимом, а також
ефективного локального балансування потужності з урахуванням пріоритетності споживачів. Мета. Розроблення принципів
побудови потужних трифазних мікромереж, здатних в умовах нестабільного загального електропостачання забезпечити
безперебійне та високоякісне електроживлення промислових підприємств з критично важливими енергоспоживачами.
Методика. Дослідження ґрунтується на системному аналізі міжнародних стандартів та сучасних публікацій у галузі
мікромереж, теорії ієрархічного керування, методах комп’ютерного моделювання режимів мікромережі, а також на
узагальненні досвіду проєктування, монтажу та тривалої (понад один рік) дослідно-промислової експлуатації мікромережі
потужністю більше 1,5 МВА на реальному промисловому підприємстві України. Результати. Розроблено та систематизовано
шість базових принципів побудови потужних промислових мікромереж. Ефективність цих принципів підтверджена успішною
роботою спроєктованої мікромережі, яка включає когенераційну установку (до 1,5 МВт), дизель-генератор (до 825 кВт),
сонячну станцію (72,5 кВт), чотири спеціалізовані джерела безперервного живлення загальною потужністю 1,95 МВт та
накопичувач електроенергії ємністю до 10 МВтꞏгод. Наукова новизна. Вперше розроблено принципи побудови потужних
трифазних промислових мікромереж у вигляді системи шести взаємопов’язаних принципів, які на відміну від існуючих підходів
охоплюють фізичні аспекти стабілізації, системні аспекти керування та якісні аспекти електроенергії (компенсацію реактивної
потужності, симетрування навантаження). Запропоновані принципи призначені для мікромереж потужністю понад 1 МВА і
враховує специфіку промислового підприємства. Практична значимість. Запропоновані принципи складають методологічну
основу для проєктування та модернізації потужних промислових мікромереж в Україні та інших країнах з нестабільним
електропостачанням. Бібл. 36, рис. 3.
Ключові слова: потужна електрична мікромережа, безперебійність електроживлення, локальний баланс потужності,
джерела електроенергії, накопичувачі електроенергії.
Introduction. In the conditions of unstable general
power supply, one of the most relevant approaches to
ensuring uninterrupted and high-quality power supply of
industrial enterprises with critically important energy
consumers is the creation of microgrids with efficient
autonomous sources and accumulators of electricity [1–3].
Microgrids should have powerful autonomous sources of
electricity, energy-intensive and powerful accumulators of
electricity, and specialized high-speed electronic devices
for stabilizing local energy and electromagnetic processes
[4]. Given the limited power of autonomous energy sources
in the microgrid, it is necessary to have a smart high-speed
control of available energy resources and their consumption
modes. And the microgrid should provide the necessary
energy and electrodynamic modes both during synchronous
Electrical Engineering & Electromechanics, 2026, no. 4 75
operation with the external macrogrid, and during long-
term autonomous operation and when implementing the so-
called «seamless» transitions between the specified modes.
The general definition of a microgrid is given in [5–7]
and is formulated as a low and/or medium voltage power
grid that includes distributed power generation sources and
can operate both in an isolated mode and in parallel with an
external power system. According to the IEEE 1547.4
Standard, an island power system with distributed
generation can be considered a microgrid if it has: 1) its
own autonomous (in particular, renewable) sources of
electricity and electricity consumers (i.e., electrical loads);
2) the ability to disconnect from the general power supply
system and operate in parallel with it, i.e., in a separate
island mode; 3) a local power system; and 4) is specially
designed [8, 9].
The goal of the work is to develop principles for
building powerful three-phase microgrids capable of
providing uninterrupted and high-quality power supply to
industrial enterprises with critical energy consumers in
conditions of unstable general power supply.
According to generally accepted requirements [5–7],
microgrids must have a controllable nature and strategic
interaction with the external macrogrid both during
synchronous operation with it and during long-term
autonomous («island») modes and «seamless» transitions
from synchronous to autonomous modes and vice versa.
A microgrid with a power of more than 1.5 MWA
was created using a cogeneration plant (with an active
power of up to 1.5 MW and a reactive power of up to
0.5 MVAr), a diesel generator with a power of up to
825 kW and a solar station with a power of up to 72.5 kW.
Given the limited power of the microgrid, 4 specialized
uninterruptible power supplies (UPS) with a power of 250,
400, 500, 800 kW were introduced into its composition to
stabilize the modes of 4 critically important energy
facilities and an energy-intensive (up to 10 MWh) and
powerful (up to 2.5 MW) modern electricity storage to
stabilize transient electromagnetic processes during
powerful switching and rapid changes in energy-intensive
modes. All generators and electricity storage were
combined into a single power system of the enterprise – a
microgrid, schematically shown in Fig. 1.
Когенератор
Зовнішня
мережа
Промислове
виробництво
Сонячна станція
Силовий
трансформатор
ДБЖ
Накопичувач
Solar plant UPS
External grid
Industrial
production
Cogenerator Storage device
Power
transformer
Fig. 1. Microgrid as a single power system of the enterprise
Enterprise electricity consumers can be divided into
three types. The first is critical electrotechnological
equipment, which cannot be left without power even for a
short time (for 2–10 ms) when the external power grid is
switched off, therefore the microgrid provides for the
presence of 4 specialized UPS. The second type is
electrical equipment, which, if necessary, can be switched
off for a certain time. The third type of equipment is
emergency and measuring equipment and power
transformers in idle mode. It has a relatively small power,
but it must also be constantly connected to a source of
electrical energy.
The introduction of a powerful microgrid provided
the enterprise with not only independent power supply,
accumulation and stabilization of peak loads, but also at
certain time intervals the generation of electricity into the
external network for the power supply of other
consumers. Of course, together with these measures, such
energy-saving technologies were implemented at the
enterprise as insulation of premises, installation of
frequency converters, heat utilisers, energy-saving
equipment, modernization of the electricity accounting
system, etc. And in order to increase the effectiveness of
the microgrid, a method of computer modeling and
analysis of various scenarios of its operation and selection
of the most energy-efficient use was developed and
implemented [4].
The implementation of the above-mentioned energy
strategy allowed the enterprise to move from the status of
«consumer of electric energy» to the status of «active
consumer», according to which it became possible to
provide its generating and accumulating equipment not
only with its own needs for electricity, but also to supply
up to 50 % of the total volume of its annual consumption
to the city electricity grid for third-party consumers in the
periods when its value is the greatest. This enabled the
enterprise to receive additional funds for its
electrotechnological improvement. But the main thing is
the emergence of own capabilities to ensure uninterrupted
and high-quality power supply of critical consumers in
case of unstable general power supply.
Currently, certain theoretical principles have already
been created for the design of traditional single-phase
distribution microgrids of small power [8, 9]. However,
their analysis shows that they do not take into account the
electrical energy and electrodynamic features of building
powerful three-phase microgrids capable of providing
uninterrupted and high-quality power supply to industrial
enterprises with critical consumers in conditions of
unstable general power supply. Therefore, the article
presents the development of principles for the building of
microgrids, which are an expanded set of fundamental
principles (six such principles are formulated below),
which distinguish them from traditional microgrids and can
be used in the modeling, design and operation of powerful
microgrids, in particular three-phase microgrids, capable of
providing uninterrupted and high-quality power supply to
industrial enterprises with critical consumers in conditions
of unstable general power supply.
We include the following six main principles of
microgrid building: the concept of a single entity (in other
words, single controllability), the principle of duality of
modes, the principle of control hierarchy, the problem of
low inertia, local power balance and power limitation.
Thus, we present the principles of building powerful
three-phase microgrids as a set of six basic principles
schematically presented in Fig. 2.
76 Electrical Engineering & Electromechanics, 2026, no. 4
Basic principles that
form the basis of
building microgrids
I. Principle of unified control
II. Principle of duality of modes
III. Principle of hierarchy of control
IV. Principle of low inertia
V. Principle of local power balance
VI. Principle of operation
under power constraints balance
Fig. 2. Basic principles of building microgrids
I. The principle of unified control of the
microgrid is essentially a concept (philosophical and
technical foundation) of the microgrid, which transforms
a chaotic set of generators and consumers of electricity
into structured elements of the power system of the future,
changing the paradigm according to which the traditional
power grid was previously analyzed according to the
principle of «top-down», or from big to small. Powerful
power plants generated electricity, which reached passive
energy consumers through power transmission lines
(TLs). In such a scheme, an industrial enterprise was
considered by the power system dispatcher exclusively as
an electrical load, or a point at which electricity is
consumed.
The dispatcher could not control the load, since he
did not have the opportunity to change it, but could only
predict and adjust the operation of the turbines of power
plants to it.
With the advent of distributed generation (solar
panels, wind generators, cogenerators, diesel generators,
modern energy-intensive and powerful batteries, etc.), the
old model ceases to work, and many autonomous small
sources of electricity create chaos in the power grid.
Therefore, it is proposed to create principles for
building microgrids, in which this problem can be solved
through the concept of unified controllability. Its essence
lies in the fact that a microgrid, which contains hundreds
of individual devices (inverters, batteries, charging
stations, etc.), can be perceived by the external macrogrid
as a single energy supply object. That is, the microgrid
should be perceived by the macrogrid as a «black box»
that has one input/output and is subject to clear,
unambiguous commands.
The concept of unified controllability of the
microgrid is based on 5 provisions.
1. The physical and virtual aggregation of energy
processes in a microgrid, that is, the presence of
aggregation (unification) processes in it. Indeed, various
complex processes of changing the power of electricity
generation by various sources occur in a microgrid. For
example, electricity generation by photovoltaic cells
drops with the appearance of clouds, when air
conditioners are switched on, electricity consumption
increases sharply and batteries begin to discharge to
compensate for the electricity shortage. For a distribution
system operator who manages a district substation,
monitoring each of these processes separately is too
complex a problem. Thanks to the concept of unified
controllability, the central controller of the microgrid
collects data from all internal elements and forms a single
power vector at the point of common connection.
For an external macrogrid, it looks as if the power of
electricity generation by the microgrid does not depend on
external operating conditions. That is, the microgrid hides
its internal complexity, providing the external operator
with a simple and predictable interface.
2. The controllability and dispatchability of the
microgrid. The word «controllability» in the name of the
microgrid concept is decisive. Renewable energy sources
(RES) are themselves uncontrollable (intermittent).
However, the power of photovoltaic and wind generation
depends on the intensity of sunlight and wind, regardless
of the needs of the network. Therefore, this
unpredictability of RES creates additional difficulties for
the traditional power grid.
The microgrid is able to solve this problem by
turning uncontrollable resources into a dispatchable asset
through the use of internal energy buffers (electricity
storage systems) and controlled loads, the value of which
can vary and therefore the microgrid can guarantee the
stability of energy regimes at the points of connection to
the macrogrid and the load.
For example, the macrogrid operator gives the
command: «Keep consumption at a level of no more than
100 kW for the next hour». If the sun suddenly goes
behind a cloud, an enterprise that previously consumed
electricity from solar panels on the roof will instantly
need to increase the power consumption of electricity
from the macrogrid, violating the command. But the
microgrid, which acts as a single managed entity, can
instantly compensate for the loss of solar energy by
connecting to its own batteries, or by starting a diesel
generator, or by disconnecting part of the non-priority
electrical load. At the same time, at the common
connection point of the microgrid and the macrogrid,
electricity consumption will not change and the microgrid
will fulfill its obligation to be a reliable partner,
stabilizing energy consumption from the macrogrid.
3. Two-way exchange in the microgrid and the
implementation of the «Prosumer» concept in it. This
principle turns a passive consumer into an active market
participant – a prosumer, that is, a participant in the
energy system who not only consumes electricity, but can
also accumulate it and feed it into the grid. According to
the principle of unified controllability, such a consumer
can perform various functions:
be an ideal load that can smooth out peaks in
electricity consumption by charging batteries at night and
using them during the day, which allows not to build new,
more powerful power lines;
be a virtual power plant, if there is an energy deficit
in the macrogrid, the microgrid is able to reduce its
consumption and start «generating» energy into the
general grid.
From the point of view of control theory, a
microgrid is an object with regulated power – active and
reactive. The ability to control both parameters transfers it
to the status of an active infrastructure element.
4. Provision of auxiliary services by the microgrid.
Since the microgrid has a smart inverter interface at the
input, it can maintain the quality of electricity for the
entire system, in particular:
Electrical Engineering & Electromechanics, 2026, no. 4 77
regulate the frequency if it drops in the main grid
during overload. Under these conditions, the microgrid
can automatically increase the active power output, acting
as a shock absorber;
maintain the voltage, since the microgrid can
generate and consume reactive power, stabilizing the
voltage level at the connection point, which is especially
important for long power lines;
reduce the level of higher harmonics, since modern
active filters in the microgrid can «clean up» the
sinusoidal current, improving the quality of energy for
neighbors.
Without the concept of unified control, the
coordination of such services from hundreds of individual
solar panels would be impossible.
5. Technical challenges of implementing a
microgrid. To implement this principle in practice, it is
necessary to standardize the language of interaction
between the microgrid and the external grid. The central
control system must be able to check the status of all
internal subsystems, assess their status and predict its
capabilities for the next 15 minutes, hour and day. If the
microgrid overestimates its capabilities (in particular, it
plans to reduce consumption, but the batteries turn out to
be discharged), this can lead to fines or even an accident
in the macrogrid. Therefore, the control algorithms within
the «unified controllability» must be an order of
magnitude more complex and reliable than those of
traditional consumers.
Thus, the concept of unified controllability of the
microgrid allows to overcome its complexity and
integrate various distributed generation devices into a
single power system without destroying its stability.
According to this concept, it does not matter what is
inside the microgrid – a diesel generator, a solar power
plant or battery batteries, it is important that at the output
of the microgrid, at the point of common connection, the
specified current and voltage parameters are guaranteed.
It is this principle that makes a microgrid not a
simple set of equipment, but the «bricks» from which we
can build a Smart Grid – a smart energy system of the
future [10–17].
II. The principle of duality of microgrid
operation modes is one of the six fundamental principles
that form the basis of the building of electrical microgrids.
It is critically important because it ensures the main value
of microgrids – viability. The building of microgrids is
based on the fact that the system must dynamically exist
in two «parallel realities» and be able to «seamlessly»
change them. This requires the use of different
fundamental control strategies for each state and makes
the engineering task extremely complex.
This principle covers four key phases in the
operation of a microgrid (Fig. 3):
1. Operation in a steady-state mode of connection to
the external network (parallel operation).
2. Transitional process of transition to an autonomous
(island) mode of operation of the microgrid.
3. Operation in a steady-state autonomous (island)
mode.
4. Transitional process of connection to the external
macrogrid (resynchronization process).
Робота мікромережі
разом із зовнішньою
мережею
(паралельна робота)
Автономна робота
мікромережі
(острівний режим)
Перехід в острівний
режим
Підключення до
зовнішньої мережі
(процес ресинхронізації)
Microgrid operation
together with the
external grid (parallel
operation)
Transition to island
mode
Connecting to an
external network
(resynchronization process)
Autonomous operation
of the microgrid
(island mode)
Fig. 3. Four key phases in microgrid mode
1. External grid connection mode. In this mode, the
microgrid is physically connected to the macrogrid
through a common connection point. The macrogrid acts
as a source of infinite power, which is an ideal voltage
source. Under such conditions, local changes in the
microgrid cannot affect the global frequency (50 Hz) and
voltage level. The internal sources of the microgrid
(batteries with inverters) operate in the active (P) and
reactive (Q) power control strategy (Grid-Following).
They do not try to regulate the frequency, but adjust to the
sine wave of the external grid using phase auto-tuning of
the frequency. Their task is to generate current in the grid
in accordance with the specified active and reactive power
settings. The stability of the system is guaranteed
externally, since the microgrid is subordinate to the
external grid.
2. Transition to island operation mode. This is the
most critical moment, which can be planned (in particular,
due to high market prices or the threat of a storm) or
emergency (for example, due to a short circuit in the
external network). In the event of an emergency
shutdown, the microgrid must recognize the loss of the
external network in a matter of milliseconds (usually
10–20 ms). If it does not shut down instantly, its
generators will start supplying the emergency in the
external network, which threatens the safety of personnel
and can lead to the collapse of the microgrid. A
specialized switching device or a high-speed mechanical
switch is used to physically break the connection at the
common connection point of the microgrid and the
macrogrid.
3. Autonomous operation mode of the microgrid. As
soon as the connection with the macrogrid is broken, the
«infinite bus» disappears, and the microgrid becomes
vulnerable to any change in load that will cause frequency
and voltage fluctuations. In this case, it is necessary to
change the control strategy (Grid-Forming) and the
control system must instantly change the logic. At least
one source (usually the most powerful, a cogenerator or a
diesel generator) takes on the role of the leading source,
switching from current source mode to voltage source
mode. This source forms the network (Grid-Forming),
setting a reference sine wave of 50 Hz and 230 V for all
other devices. Since there is almost no inertia in the
microgrid (see principle IV below), the law of
conservation of energy requires an instant balance: the
generation power is equal to the sum of the consumption
power and losses. If consumption exceeds generation, the
frequency can «fall» and the system can «go out» in a
78 Electrical Engineering & Electromechanics, 2026, no. 4
fraction of a second. The principles of building require the
instant involvement of load control mechanisms.
Automation must quickly disconnect secondary lines
(non-priority consumers) in order to save a stable power
supply to the critical load. This is part of the V principle,
which provides for power supply to priority consumers
even at the expense of disconnecting non-priority ones.
4. Resynchronization mode (return to the external
grid). After the external grid is restored, it is impossible to
simply close the circuit breaker at the common connection
point of the microgrid and the macrogrid, since the sine
wave of the microgrid in autonomous mode can «drift»
and not coincide in phase with the external grid. The
resynchronization process is a critical secondary control
function and requires active actions. The microgrid
controller measures the voltage, frequency and phase
angle of the external grid (at the open common
connection point circuit breaker). It must send commands
to the internal generators/batteries with inverters to
«match» the frequency and phase and implement the
resynchronization mode. When the difference in
parameters becomes almost zero, i.e. so small that it
meets the conditions of synchronism, the controller closes
the switch of the common connection point and the
system can smoothly return to the parallel operation mode
with the macrogrid.
Thus, the principle of duality of modes provides the
microgrid with the ability to adapt to new conditions and
continue functioning, thereby ensuring the viability of the
critically important load. Additional information on the use
of such a principle in specific cases is given in [18–22].
Principle III. Hierarchy of control. This principle is
the fundamental basis that ensures the functionality of
electrical microgrids, allowing them to simultaneously
solve opposing tasks: from instant response to physical
accidents to long-term economic optimization. Note that
the proposed principles for building microgrids consider
the microgrid as a complex cyber-physical system in which
power electrical equipment and «cybernetics» (primarily
control algorithms) are inextricably linked. This principle
solves the engineering problem of «how to control»
processes that occur in the time range from microseconds
(transistor switching) to hours (changing market prices).
Attempting to solve these tasks with a single central
processor would lead to a catastrophe. In particular, if the
communication channel «hangs» during the transmission of
economic data, the system will not have time to react to a
short circuit. Therefore, the International Standard (based
on IEC/ISO 62264) defines a three-level control hierarchy:
primary, secondary and tertiary control.
Level 1. Primary control, which occurs directly at the
level of local devices: solar panel inverters, battery
controllers, diesel generator regulators, etc. The time range
of this level is milliseconds (1–100 ms). The main feature
of such control is complete decentralization, in which
individual devices do not «communicate» with each other.
The mechanism of action is the control of voltage and
frequency drops. Since there are no communication cables
at this level (they are too slow and unreliable for
millisecond reactions), the inverters analyze the physical
parameters of the current through the power wires
themselves.
The current frequency f in the microgrid depends on
the active power P. In particular, if a powerful electric
motor is switched on, the load increases and the frequency
in the network decreases slightly (for example, from 50.0
Hz to 49.8 Hz). Local programs of all other inverters in the
network automatically increase the power output, thereby
increasing and stabilizing the frequency.
The pair «voltage U – reactive power Q» works
similarly. If the voltage at the connection point drops, the
inverter automatically increases the reactive power to raise
the voltage.
At the same level, virtual inertia is created, that is,
algorithms are implemented that force inertialess
electronics to simulate the physical mass of the turbine
rotor, preventing too sharp frequency changes.
Level 2. Secondary control. If the primary control
saves the system from collapse, then the secondary control
brings it to the regulatory quality parameters. The time
range of this level: seconds – minutes (approximately from
100 ms to 5 min). The main feature is the need for
communication channels (Ethernet, Wi-Fi, GSM) and
coordination.
The main functions of this second level are:
1. Frequency and voltage recovery. For example, if the
central microgrid controller or a distributed agent system
determines that the frequency is held at 49.8 Hz, a
command is sent to all generators to increase power so that
the frequency increases to 50.0 Hz.
2. Synchronization, as a critical function of the second
level. In particular, if the microgrid needs to be connected
to the macrogrid after autonomous operation, then
secondary control must be used to adjust the phase of the
internal voltage of the microgrid to the external voltage of
the macrogrid. Without this level of connection, connection
is impossible.
3. Distribution of reactive power, if it is poorly
transmitted over a long distance and causes circulating
currents between inverters. Then secondary control must be
used, which must ensure voltage uniformity throughout the
microgrid, and not just near the power source.
Level 3. Tertiary control. This is the highest, «slow»
level. It is not responsible for physics, but deals mainly
with economics (the cost of kilowatts). Time range:
minutes – hours – day. Its main feature is global
optimization and interaction with the external environment.
For example, if there are three sources of electricity in a
microgrid: solar panels (cheap electricity), a diesel
generator (expensive electricity), a storage battery (limited
resource), then tertiary control solves the optimization
problem: how to cover the current demand for electricity
with minimal costs. In particular, the controller may decide
to start the diesel at night, because the storage battery is
discharged. During the day, it turns off the diesel and
charges the battery from solar panels.
Complex algorithms are used to predict and make
such decisions, so it is advisable to use artificial
intelligence algorithms and predict in advance, in
particular:
weather and changes in the brightness of the sun;
changes in the power of the electrical load at the
enterprise;
Electrical Engineering & Electromechanics, 2026, no. 4 79
changes in the cost of electricity in the external power
grid.
Based on the available forecasts, a plan for the current
use of electric generators and electricity storage is formed,
which is called «energy arbitrage».
Thus, the hierarchical control theory is the basis on
which the microgrid rests. It allows to combine almost
incompatible:
reliability of the microgrid operation (due to the
autonomous primary level);
power quality (due to the corrective secondary level);
energy and economic efficiency (due to the intelligent
tertiary level).
Without such a structure, the microgrid will be an
unstable system that will have difficulty competing with
traditional energy systems. It is the hierarchy that turns a
set of iron into a Smart Grid. Examples of the use of this
principle are given, in particular, in [23–26].
Principle IV. The problem of low inertia. This
principle is one of the six fundamental principles of
electrical microgrid design, which addresses the critical
physical problem of system stability in the first
milliseconds after an accident. This principle is crucial for
understanding how a microgrid based on digital
electronics can achieve the reliability inherent in
traditional power systems that use the inertia of powerful
turbines.
The traditional power system is a world of large
inertial masses. The turbines of nuclear, thermal and
hydraulic electric power plants have a mass of hundreds
of tons and rotate at a speed of 3000 rpm, accumulating
enormous kinetic energy that acts as a giant flywheel or
shock absorber. If a line suddenly goes out or the load
increases sharply, the turbines cannot stop instantly. They
continue to spin by inertia, giving their kinetic energy to
the network until the automation gives more steam to the
turbine blades. This buffer time (a few seconds) gives the
control system a chance to react and save the situation.
A microgrid is a world of digital electronics. Solar
panels and batteries are connected to the grid through
high-speed semiconductor inverters, which have no
moving parts and no kinetic inertia. The theoretical
problem here is how to ensure the stability of a system
that has lost its natural physical shock absorber in time?
The nature of the problem: the rate of change of
frequency and the value of the frequency. In the power
industry, the frequency of change of current 50 Hz is an
indicator of balance; if the generation of electricity is
equal to its consumption, then the frequency of change of
current is stable and equal to 50.0 Hz. If consumption
exceeds generation, then this frequency drops.
In a system with high inertia (traditional grid), the
frequency drop occurs slowly. In a system with low
inertia (microgrid), the drop occurs almost instantly.
Therefore, a key design parameter is introduced: Rate of
Change of Frequency (df/dt) – RoCoF.
In microgrids, df/dt can be extremely high. For
example, if a cloud blocks the sun over a solar station, the
frequency can drop from 50 Hz to 48 Hz in 0.1 s.
The consequences of such a high df/dt can be:
false triggering of relay protection configured to
disconnect equipment in case of frequency deviations. In
particular, with a high df/dt, it can disconnect even
working generators, which can lead to a cascade accident
(Blackout);
inability to implement regulation, since traditional
diesel generator speed controllers are mechanical and
slow, so they simply will not have time to react to the
frequency drop and the entire system may collapse.
The role of power electronics. The root of the problem
is the nature of semiconductor converters, particularly Grid-
Following inverters. They measure the sinusoidal voltage in
the electrical outlet and adjust their output current to this
sinusoidal voltage and behave like ideal current sources.
From the point of view of physics, a current source has
infinite impedance and zero inertia, so it does not resist
changes in voltage and frequency. If the external network
«oscillates», then the inverter in Grid-Following mode will
not try to stabilize the frequency, it will simply stay on it, and
if it does not work, it will turn off. In a microgrid, where
100 % of the sources will have such inverters, there is
nothing to support the frequency. The system becomes
unstable by definition.
The theoretical solution to this problem is the
introduction of virtual inertia, in the role of which the
algorithmic simulation of the behavior of a synchronous
generator acts. Using the equation of motion of the generator
rotor, the inverter microcontroller is programmed to solve
this equation in real time. At the same time:
1) the inverter measures the frequency change rate
df/dt;
2) if the frequency drops, the algorithm calculates how
much energy a heavy turbine would give due to such braking
under such conditions;
3) the inverter forcibly delivers this calculated amount
of energy to the grid, taking it from the DC bus from the
battery or other electricity storage.
This solution turns passive electronics into an active
energy damper. The inverter can work out the frequency
change by artificially reducing df/dt.
Evolution of management. Solving the problem of low
inertia leads to the appearance of a new class of equipment –
Grid-Forming Inverters. Unlike Grid-Following Inverters,
which adapt to the grid, these inverters behave as voltage
sources:
they do not measure the frequency to adjust to it;
they generate their own frequency and voltage, rigidly
holding it;
if the load tries to «decrease» this frequency, the
inverter instantly (without complex calculations, simply
according to the laws of the electric circuit of Ohm and
Kirchhoff) gives the current necessary to maintain stability.
Grid-Forming inverters provide the so-called «instant
inertia». They make the microgrid «hard». However, this
requires a significant supply of energy (batteries) that can be
instantly transferred to the grid. A solar panel by itself cannot
be Grid-Forming, because it cannot give more energy than it
produces from the light of the sun at the moment. Therefore,
the problem of inertia is inextricably linked with energy
storage systems.
Fast response reserves. Since virtual inertia only
«slows» the frequency drop, but does not stop it
completely, the design principles introduce the concept of
80 Electrical Engineering & Electromechanics, 2026, no. 4
Fast Frequency Response (FFR). In a traditional grid,
primary regulation takes about 10–30 s. In a low-inertia
microgrid, there is no such time. FFR is a mechanism that
allows batteries to deliver full power in less than 1 s (and
often in 0.2–0.5 s), which creates a theoretical paradox:
we are trading mass for speed. The old grid has a lot of
mass, slow response. The microgrid has zero mass,
ultrafast response. The theory states that with a
sufficiently fast response of the control system (ultrafast
digital controllers, fiber optics, transistors), it is possible
to ensure stability even without physical inertia.
Measurement challenges. Another problem with
low inertia is the problem of measurement.
Most inverters use a Phase Locked Loop (PLL) to
determine the grid frequency.
In «weak» microgrids with low inertia, the voltage
can be distorted by higher harmonics or sharp phase
jumps and the PLL can mistakenly give an incorrect
frequency value. The inverter can react to this as a
malfunction and try to «fix» it by increasing the power.
But this can actually only worsen the situation and lead to
self-oscillations and system collapse. Therefore, modern
theory focuses on the development of robust (stable)
synchronization algorithms that can distinguish real
frequency changes from measurement noise in low inertia
conditions.
Thus, the emergence of the low inertia problem is
the price for abandoning fossil fuels and heavy electric
machines. It forces us to reconsider the fundamental
principles of stability that have worked for many years.
The solution lies in the transition from physical
stabilization (flywheels) to algorithmic stabilization
(program code). A low inertia microgrid relies on the
intelligence of inverters and the response speed of
batteries to maintain balance under conditions of chaotic
load and generation changes. Examples of solutions to
this problem are given in [26–29].
Principle V. Local power balance. While the
previous principles (isolated operation, inertia, hierarchy)
were mainly physics-based, this principle is about logic,
economics, and behavior. It reflects a fundamental shift in
the philosophy of energy consumption, in particular, the
transition from consumer dictates to adaptation to nature’s
capabilities. In classical energy (macrogrids), the
unbreakable rule has long been in effect: «generation
follows load». The system is required to meet electricity
demand at any given time.
In microgrids, especially those based on renewables,
this rule does not work. Generation is stochastic and
limited. Therefore, the principles of microgrid building
introduce a new paradigm: «load follows generation».
This means that energy consumption is no longer a
constant or arbitrary value. It is a variable that must be
actively managed to fit into the available generation
budget.
The main difference between microgrids of
industrial enterprises and urban and rural microgrids of
widespread use is their power, which should exceed the
power of critical energy consumers. Therefore, it is
important to develop principles for building microgrids
with a power of more than 1 MVA, capable of
implementing uninterrupted and high-quality power
supply of industrial enterprises with unstable general
power supply.
Typically, microgrids of such power will already be
three-phase, and the loads will be single- and two-phase,
and for their energy-efficient use, it is necessary to solve
the problems of reducing the level of high-frequency
harmonics, the magnitude of reactive power, balancing
single- and two-phase loads, etc. In addition, the
developed principles, without revealing the internal
complexity of microgrids, should implement their
controlled nature and strategic interaction with the
external macrogrid during synchronous operation with it,
during long-term autonomous («island») modes and
during the so-called «seamless» transitions between these
modes [4].
Classification of loads. The basis of local balance is
the understanding that energy for powering, for example,
critical technological equipment [30] and energy for
lighting warehouses have different values. The principles
of building microgrids require strict categorization
(segmentation) of all consumers:
1. Critical electrical load.
This is electrical equipment, in particular, continuous
electrical technological lines of the enterprise, electrical
servers, security systems, microgrid controllers, etc., the
disconnection of which is unacceptable, therefore it must
receive power at any cost.
2. Priority load.
Important electrical equipment, which, if necessary,
can be disconnected for a certain time (in particular,
electrical equipment with short periods of continuous
operation), lighting of non-core production premises and
other non-critical electrical equipment of the enterprise.
3. Non-priority controlled load.
Consumers, the operation of which can be postponed
in time or reduced in power without compromising comfort.
These are lighting, heating, air conditioning systems, etc.
This load category is the main key to the balance of
power consumption from the microgrid. In a «smart»
microgrid, it is desirable that these loads account for
30–50 % of the total power consumption, which would give
ample room for maneuver.
Demand management. This is a «soft» tool for
balancing energy consumption. Instead of forcing the lights
to turn off, the control system encourages consumers to
change their behavior or automatically adjusts the
parameters of devices.
Automatic regulation. For example, when a cloud
covers the sun and local generation drops, the microgrid
controller sends a signal to the air conditioning system to
increase the temperature setpoint. For people, this is almost
imperceptible, but for the power system, this is an instant
reduction in consumption by tens of kilowatts. When the
sun comes out again, the system returns the temperature
setpoint to the previous level, effectively using the thermal
inertia of the building.
Economic incentives. The internal price of energy in a
microgrid can be dynamic. For example, at noon (when
there is an excess of sunlight), energy in a microgrid with
solar stations costs much less, so the controller can turn on
the charging of batteries, accumulating electricity in them
for later.
Electrical Engineering & Electromechanics, 2026, no. 4 81
During the evening peak, when there is a shortage of
energy, its price increases significantly. Smart devices
automatically pause energy-intensive processes in the
enterprise that are not continuous. This creates a virtual
power plant. Reducing consumption, for example, by
100 kW to balance the system is equivalent to starting a
100 kW generator, but it is cheaper and more
environmentally friendly.
Load shedding. This is a «hard» balancing tool that is
used in emergency situations (mainly in the island mode of
operation of the microgrid). When there is a threat of a
complete blackout due to overload, the Intelligent Load
Shedding algorithm is activated. Unlike old automatic
frequency shedding (AFS) systems that switched off entire
areas, this microgrid algorithm acts selectively:
1. The microgrid knows the exact consumption of each
feeder.
2. Specific consumers or lines with the lowest priority
are disconnected.
3. The process takes place in milliseconds to stabilize
the frequency.
This allows the microgrid to operate autonomously
for weeks, powering only critical infrastructure with the
remnants of solar energy and diesel generator energy for
survival.
The role of electric energy storage. Although
batteries are often considered sources of electricity, in the
context of its balance they are buffer storage. The main
problem of the balance of electricity is the discrepancy in
its generation and consumption over time.
The sun shines during the day and this is the peak of
energy generation at the solar station, and people come
home in the evening and create a peak of its consumption.
Therefore, the principle of local balance requires the
implementation of a certain strategy for managing the
charge of the battery, i.e. changing its State of Charge
(SoC). The controller does not simply charge the battery
when there is energy, it predicts the future: for example, if
the forecast is that tomorrow will be cloudy, then the
algorithm of its actions at night will be to partially
discharge the battery in order to leave up to 50 % of the
charge for the morning, as an energy reserve in case of a
morning accident or other need.
Considering that thermal and chemical energy
storage technologies are simpler and cheaper than
electrical energy, it is advisable to implement the
principle of combining the electrical network with the
thermal network and transport.
Summarizing the results of the section devoted to the
implementation of principle V, we note that the principle of
local power balance turns the microgrid into a self-
sufficient organism. It removes the balancing burden from
the national energy system and transfers it to the local
level. This changes the role of the enterprise (and even just
an individual): from passive subscribers who simply pay
their bills, they become active participants in the energy
market («prosumers»), whose smart devices (and
household habits) become part of a large mechanism for
stabilizing the energy system. Without this principle, a
microgrid becomes simply a set of expensive electrical
appliances. Using this principle, it becomes an
economically efficient and technically sustainable structure.
The principle of local power balance also allows for
reliable power supply at the enterprise of critically
important electrical equipment. For this, the enterprise,
firstly, allocates a category of such equipment, and,
secondly, creates appropriate power capacities that are
sufficient for its power supply. Some examples of the use
of this principle are given in [31–34].
Principle VI. Microgrid operation under power
constraints. This principle is the final of the six
fundamental principles that form the principles for
building powerful electric microgrids. It focuses not on
controlling the microgrid modes, but on the consumer’s
requirements for the enterprise’s electrical equipment
necessary for the reliable operation of the microgrid. This
principle is considered in the context of an industrial
microgrid operating in power constraints, i.e. in island
mode.
The need for equipment adaptation. In a traditional
power system, the external network is considered a source
of large (conditionally unlimited) power. This excess
power allows us to ignore the shortcomings of electrical
equipment that do not affect the stable operation of the
macrogrid. However, a microgrid in island mode operates
under power constraints, so if the consumer’s equipment
does not meet high energy quality standards, this can have
significant consequences for the stability of the
microgrid’s power modes. Therefore, the principles of
microgrid building require special attention to the quality
of electrical equipment to ensure reliable operation in the
limited power mode.
Key challenges and requirements. Principle VI
identifies three main challenges that need to be addressed
when operating powerful microgrids in limited power
conditions.
1. The problem of power quality (reducing the level
of higher harmonics). It is necessary to take into account
the quality of industrial loads that use power electronics
(in particular, thyristor converters of power parameters)
and can generate higher harmonics of current and voltage.
The generation of higher harmonics in the microgrid load
can lead to poor-quality operation of semiconductor
inverters of RES, which is critically important in forming
the network and maintaining the frequency of current and
voltage, since inverters that work as grid-forming voltage
and current of the microgrid are quite sensitive to such
distortions. This problem can be solved, in particular, by
using LCL filters, which can significantly improve the
quality of electricity [35]. However, it should be noted
that their efficiency is significantly affected by the line
impedance, which can lead to resonances and instabilities
in the microgrid.
2. Reactive power compensation. In microgrids,
solving the problem of reactive power compensation in AC
circuits is a very important problem that directly affects
voltage stability and power quality [36]. The efficiency of
microgrids can be significantly improved by supporting
control and compensation of reactive power exchange. This
problem becomes especially critical in the absence of an
external power grid, that is, when the microgrid operates in
island mode. The presence of significant reactive power
flows in the microgrid leads to an additional load on power
electronics and its control systems. In addition, power
82 Electrical Engineering & Electromechanics, 2026, no. 4
source inverters, in the presence of reactive power, reduce
the active power transmitted to the microgrid. To estimate
the active power of the inverter, the following approximate
expression can be used:
,222
invinvinv QSP
where Sinv Pinv and Qinv are its installed, active and
reactive power, respectively.
3. The problem of asymmetry (connection of single-
and two-phase loads in three-phase microgrids). In an
external high-power network, it is possible to connect a
single-phase load to a three-phase network without
significant impact on its modes. In the case of three-phase
microgrids operating in island mode, connecting even a
low-power single-phase device to them, in particular a
thyristor induction heating unit for metal products, in
three-phase circuits can cause significant phase
asymmetry, which in turn can complicate the operation of
semiconductor inverters that try to set the required
frequency and voltage for the entire microgrid. To solve
this type of problem, it is necessary to use additional
balancing devices that use L, C elements connected, for
example, according to the Steinmetz circuit.
So, if the previous five principles concern how a
powerful microgrid manages the main elements of the
system and implements the processes of interaction with
the external macrogrid, then principle VI is a kind of
«internal quality control» for the microgrid – it is aimed at
increasing the energy efficiency of electrical power and
technological equipment in an industrial microgrid.
It justifies that in order to increase the efficiency of
the operation of powerful three-phase microgrids,
especially when they operate in island mode, it is
necessary to solve 3 problems: improving the quality of
electricity, compensating for reactive power, and
eliminating the asymmetry of the connection of single-
and two-phase loads in three-phase microgrids.
This is particularly necessary to improve the quality
of operation of semiconductor inverters that support the
efficiency and stability of energy modes in three-phase
microgrids.
Conclusions.
1. The work develops the principles of building
powerful microgrids for uninterrupted power supply of
industrial enterprises in conditions of unstable external
power supply and justifies the need to transition from
passive distribution of electricity to active management of
available local energy resources with a certain uncertainty
of energy processes and the absence of physical inertia of
ensuring power supply modes of energy consumers under
different conditions.
2. The principles of building powerful industrial
microgrids are developed using six basic principles: 1)
unified controllability of microgrids; 2) duality of long-
term and stable modes of microgrids; 3) hierarchy of
control (i.e. ensuring speed and economy); 4) low inertia
(which requires algorithmic stabilization); 5) local power
balance (which consists in managing demand for
survival); 6) operation of the microgrid in conditions of
limited power (under conditions of ensuring electricity
quality, compensation of reactive power and elimination
of load asymmetry).
3. The effectiveness of the proposed principles for
building powerful microgrids was verified during the
design, experimental research and long-term (more than
1 year) operation of a microgrid with a power of more
than 1.5 MVA, created at one of the industrial enterprises
of Ukraine to ensure uninterrupted and high-quality
power supply to critically important energy facilities
during unforeseen long-term power outages of this
enterprise from the national power system.
4. The key areas of microgrid development for the next
decade should be considered: 1) creation or re-equipment
of technological equipment at industrial enterprises that
must operate reliably under power limitations, 2)
introduction of advanced Grid-Forming inverters to solve
the inertia problem, 3) use of distributed control
algorithms to increase reliability, and 4) integration of
artificial intelligence methods for effective energy
management.
Acknowledgment. The work was carried out at the
expense of the research work «Ensuring the effectiveness
of the functioning and development of distributed energy in
Ukraine using microgrid technologies» (code «Mode 3»),
KPKVK 6541230.
Conflict of interest. The authors declare no conflict
of interest.
REFERENCES
1. Pandey A.K., Padmanaban S., Tripathi S.L., Patel V., Patel V.
Microgrids. Design, Optimization, and Applications. CRS Press, 2024.
320 p. doi: https://doi.org/10.1201/9781003481836.
2. Patrao I., Figueres E., Garcerá G., González-Medina R. Microgrid
architectures for low voltage distributed generation. Renewable and
Sustainable Energy Reviews, 2015, vol. 43, pp. 415-424. doi:
https://doi.org/10.1016/j.rser.2014.11.054.
3. Pabbuleti B, Somlal J. A review on hybrid ac/dc microgrids: optimal
sizing, stability control and energy management approaches. Journal of
Critical Reviews, 2020, vol. 7, no. 2, pp. 371-381. doi:
https://doi.org/10.31838/jcr.07.02.72.
4. Shcherba A.A., Podoltsev O.D., Belyanin R.V., Antonets T.Y.,
Dadazhanov Y.V. Modeling and analysis of long-term 24-hour processes
of changes in electrical energy flows in the microgrid of an industrial
enterprise. Tekhnichna Elektrodynamika, 2026, no. 1, pp. 62-71. (Ukr).
doi: https://doi.org/10.15407/techned2026.01.062.
5. SGCG/M490/G_Smart Grid Set of Standards 25 Version 3.1. CEN-
CENELEC-ETSI Smart Grid Coordination Group, 2014. 259 p.
6. IEC TS 62898-1: 2017+AMD 1: 2023 Microgrids – Part 1:
Guidelines for microgrid projects planning and specification. 2023. 78 p.
7. IEC TS 62898-2: 2018/AMD1:2023 Microgrids – Part 2: Guidelines
for operation. 2023. 38 p.
8. Blinov I., Trach I., Parus Y., Khomenko V., Kuchanskyy V.,
Shkarupylo V. Evaluation of The Efficiency of The Use of Electricity
Storage Systems in The Balancing Group and The Small Distribution
System. 2021 IEEE 2nd KhPI Week on Advanced Technology
(KhPIWeek), 2021, pp. 262-265. doi:
https://doi.org/10.1109/KhPIWeek53812.2021.9569981.
9. Kroposki B., Basso T., DeBlasio R. Microgrid standards and
technologies. 2008 IEEE Power and Energy Society General Meeting -
Conversion and Delivery of Electrical Energy in the 21st Century, 2008,
pp. 1-4. doi: https://doi.org/10.1109/PES.2008.4596703.
10. Hatziargyriou N. Microgrids: Architectures and Control. Wiley-
IEEE Press, 2014. 344 p.
11. Peng Zhang P. Microgrids. Theory and Practice. Wiley-IEEE Press,
2024. 944 p.
12. Chowdhury S., Chowdhury S.P., Crossley P.P. Microgrids and
Active Distribution Networks. IET Renewable Energy Series, 2009. 320
p. doi: https://doi.org/10.1049/PBRN006E.
13. Narejo G.B., Acharya B., Singh R.S.S., Newagy F. Microgrids:
design, challenges, and prospects. CRC Press, 2021. 420 p.
Electrical Engineering & Electromechanics, 2026, no. 4 83
14. Sirviö K.H., Laaksonen H., Kauhaniemi K., Hatziargyriou N.
Evolution of the Electricity Distribution Networks – Active Management
Architecture Schemes and Microgrid Control Functionalities. Applied
Sciences, 2021, vol. 11, no. 6, art. no. 2793.
https://doi.org/10.3390/app11062793.
15. Joos G., Reilly J., Bower W., Neal R. The Need for Standardization:
The Benefits to the Core Functions of the Microgrid Control System.
IEEE Power and Energy Magazine, 2017, vol. 15, no. 4, pp. 32-40. doi:
https://doi.org/10.1109/MPE.2017.2690518.
16. Reilly J.T. From microgrids to aggregators of distributed energy
resources. The microgrid controller and distributed energy management
systems. The Electricity Journal, 2019, vol. 32, no. 5, pp. 30-34. doi:
https://doi.org/10.1016/j.tej.2019.05.007.
17. Lopes J.A.P., Madureira A.G., Moreira C. A View of Microgrids.
Advances in Energy Systems, 2019, pp. 149166. doi:
https://doi.org/10.1002/9781119508311.ch9.
18. Zhao B., Shi Y., Dong X., Luan W., Bornemann J. Short-Term
Operation Scheduling in Renewable-Powered Microgrids: A Duality-
Based Approach. IEEE Transactions on Sustainable Energy, 2014, vol.
5, no. 1, pp. 209-217. doi: https://doi.org/10.1109/TSTE.2013.2279837.
19. Ashabani S.M., Mohamed Y.A.-R.I. A Flexible Control Strategy for
Grid-Connected and Islanded Microgrids With Enhanced Stability Using
Nonlinear Microgrid Stabilizer. IEEE Transactions on Smart Grid, 2012,
vol. 3, no. 3, pp. 1291-1301. doi:
https://doi.org/10.1109/TSG.2012.2202131.
20. Jiang Q., Xue M., Geng G. Energy Management of Microgrid in
Grid-Connected and Stand-Alone Modes. IEEE Transactions on Power
Systems, 2013, vol. 28, no. 3, pp. 3380-3389. doi:
https://doi.org/10.1109/TPWRS.2013.2244104.
21. Vinh N.T., Anh D.T. Bidirectional DC/AC converter for flexible
distributed energy integration into AC microgrids. Electrical Engineering &
Electromechanics, 2026, no. 2, pp. 74-83. doi:
https://doi.org/10.20998/2074-272X.2026.2.10.
22. Adiche S., Larbi M., Toumi D. Optimizing voltage control in AC
microgrid systems with fuzzy logic strategies and performance
assessment. Electrical Engineering & Electromechanics, 2025, no. 3, pp.
11-17. doi: https://doi.org/10.20998/2074-272X.2025.3.02.
23. Yang X., Chen W., Wu L., Tuo J., Qiu N. Stability Analysis Method
of a Hierarchical Control Structure Microgrid Based on a Small-Signal
Model and Hopf Bifurcation Theory. International Journal of Electrical
Power & Energy Systems, 2024, vol. 161, art. no. 110157. doi:
https://doi.org/10.1016/j.ijepes.2024.110157.
24. Abhishek A., Ranjan A., Devassy S., Kumar Verma B., Ram S.K.,
Dhakar A.K. Review of hierarchical control strategies for DC microgrid.
IET Renewable Power Generation, 2020, vol. 14, no. 10, pp. 1631-1640.
doi: https://doi.org/10.1049/iet-rpg.2019.1136.
25. Feng X., Shekhar A., Yang F., Hebner E.R., Bauer P. Comparison of
Hierarchical Control and Distributed Control for Microgrid. Electric
Power Components and Systems, 2017, vol. 45, no. 10, pp. 1043-1056.
doi: https://doi.org/10.1080/15325008.2017.1318982.
26. Ma J., Yuan L., Zhao Z., He F. Transmission Loss Optimization-
Based Optimal Power Flow Strategy by Hierarchical Control for DC
Microgrids. IEEE Transactions on Power Electronics, 2017, vol. 32, no.
3, pp. 1952-1963. doi: https://doi.org/10.1109/TPEL.2016.2561301.
27. Dag O., Mirafzal B. On stability of islanded low-inertia microgrids.
2016 Clemson University Power Systems Conference (PSC), 2016, pp. 1-
7. doi: https://doi.org/10.1109/PSC.2016.7462854.
28. Li X., Li Z., Guo L., Zhu J., Wang Y., Wang C. Enhanced Dynamic
Stability Control for Low-Inertia Hybrid AC/DC Microgrid With
Distributed Energy Storage Systems. IEEE Access, 2019, vol. 7, pp.
91234-91242. doi: https://doi.org/10.1109/ACCESS.2019.2926814.
29. Haddadi M., Gorji S.A., Yu S.S. An Overview of Inertia Emulation
Strategies for DC Microgrids: Stability Analysis and AC Microgrid
Analogies. IEEE Open Journal of the Industrial Electronics Society, 2025,
vol. 6, pp. 491-521. doi: https://doi.org/10.1109/OJIES.2025.3550625.
30. Golpîra H., Bevrani H. Microgrids Impact on Power System
Frequency Response. Energy Procedia, 2019, vol. 156, pp. 417-424. doi:
https://doi.org/10.1016/j.egypro.2018.11.097.
31. Moon H.-J., Kim Y.J., Chang J.W., Moon S.-I. Decentralised Active
Power Control Strategy for Real-Time Power Balance in an Isolated
Microgrid with an Energy Storage System and Diesel Generators.
Energies, 2019, vol. 12, no. 3, art. no. 511. doi:
https://doi.org/10.3390/en12030511.
32. Espina E., Llanos J., Burgos-Mellado C., Cardenas-Dobson R.,
Martinez-Gomez M., Saez D. Distributed Control Strategies for
Microgrids: An Overview. IEEE Access, 2020, vol. 8, pp. 193412-
193448. doi: https://doi.org/10.1109/ACCESS.2020.3032378.
33. Yuan M., Fu Y., Mi Y., Li Z., Wang C. Hierarchical control of DC
microgrid with dynamical load power sharing. Applied Energy, 2019,
vol. 239, pp. 1–11, doi: https://doi.org/10.1016/j.apenergy.2019.01.081.
34. Hamidieh M., Ghassemi M. Microgrids and Resilience: A Review.
IEEE Access, 2022, vol. 10, pp. 106059-106080. doi:
https://doi.org/10.1109/ACCESS.2022.3211511.
35. Hernández-Mayoral E., et. al. A Comprehensive Review on Power-
Quality Issues, Optimization Techniques, and Control Strategies of
Microgrid Based on Renewable Energy Sources. Sustainability, 2023,
vol. 15, no. 12, art. no. 9847. doi: https://doi.org/10.3390/su15129847.
36. Gayatri M.T.L., Parimi A.M., Pavan Kumar A.V. A review of
reactive power compensation techniques in microgrids. Renewable and
Sustainable Energy Reviews, 2018, vol. 81, pp. 1030-1036. doi:
https://doi.org/10.1016/j.rser.2017.08.006.
Received 07.02.2026
Accepted 08.04.2026
Published 02.07.2026
A.A. Shcherba1, Academician of the National Academy of
Sciences of Ukraine, Doctor of Technical Science,
O.D. Podoltsev1, Doctor of Technical Science, Chief Researcher,
N.I. Suprunovska1, Doctor of Technical Science, Chief Researcher,
R.V. Belyanin2, PhD,
1 Institute of Electrodynamics of the National Academy of
Sciences of Ukraine,
56, Beresteisky Avenue, Kyiv, 03057, Ukraine,
e-mail: anat.shcherba@gmail.com;
podoltsev.alexander@gmail.com;
iednat1@gmail.com (Corresponding Author).
2 YUZHCABLE WORKS, PJSC,
7, Avtogenna Str., Kharkiv, Ukraine,
e-mail: roman.belyanin@ukr.net
How to cite this article:
Shcherba A.A., Podoltsev O.D., Suprunovska N.I., Belyanin R.V. Principles of building powerful microgrids for uninterrupted power
supply of industrial enterprises. Electrical Engineering & Electromechanics, 2026, no. 4, pp. 74-83. doi: https://doi.org/10.20998/2074-
272X.2026.4.10
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| spelling | eiekhpieduua-article-3660792026-07-01T21:42:56Z Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises Принципи побудови потужних мікромереж для безперебійного електроживлення промислових підприємств Shcherba, A. A. Podoltsev, O. D. Suprunovska, N. I. Belyanin, R. V. powerful electric microgrid uninterrupted power supply local power balance sources of electricity electricity storage devices потужна електрична мікромережа безперебійність електроживлення локальний баланс потужності джерела електроенергії накопичувачі електроенергії Introduction. In conditions of unstable external power supply, industrial enterprises with critical electrical technological processes require reliable backup power supply. Traditional approaches to power supply backup, based on separate diesel generators or uninterruptible power supply systems, do not provide the required quality and continuity of power supply during long-term emergency outages from the national power grid. Problem. Existing theoretical principles for building microgrids are focused mainly on single-phase distribution networks of low power and do not take into account the features of powerful three-phase industrial microgrids. In particular, the problems of ensuring system stability under conditions of low inertia (absence of rotating masses of generators) and implementing «seamless» transitions between the parallel operation mode with the external grid and the autonomous («island») mode, as well as effective local power balancing taking into account the priority of consumers, remain unresolved. Goal. Development of the principles for building powerful three-phase microgrids capable of providing uninterrupted and high-quality power supply to industrial enterprises with critical energy consumers in conditions of unstable general power supply. Methodology. The study is based on a systematic analysis of international standards and modern publications in the field of microgrids, hierarchical control theory, methods of computer modeling of microgrid modes, as well as on the generalization of experience in designing, installing and long-term (more than one year) experimental and industrial operation of a microgrid with a capacity of more than 1.5 MVA at a real industrial enterprise in Ukraine. Results. Six basic principles for building powerful industrial microgrids have been developed and systematized. The effectiveness of these principles is confirmed by the successful operation of the designed microgrid, which includes a cogeneration unit (up to 1.5 MW), a diesel generator (up to 825 kW), a solar station (72.5 kW), four specialized uninterruptible power supplies with a total capacity of up to 1.95 MW, and an electricity storage unit with a capacity of up to 10 MWh. Scientific novelty. For the first time, the principles for building powerful three-phase industrial microgrids has been developed as a system of six interconnected principles, which, unlike existing approaches, cover the physical aspects of stabilization, system aspects of control and quality aspects of electricity (reactive power compensation, load balancing). The proposed principles are intended for microgrids with a capacity of more than 1 MVA and take into account the specifics of industrial enterprises. Practical value. The proposed principles provide a methodological basis for the design and modernization of powerful industrial microgrids in Ukraine and other countries with unstable power supply. References 36, figures 3. Вступ. В умовах нестабільного зовнішнього електропостачання промислові підприємства з критично важливими електротехнологічними процесами потребують надійного резервного електроживлення. Традиційні підходи до резервування, засновані на окремих дизель-генераторах або системах безперервного живлення, не забезпечують необхідної якості та безперервності електроживлення при тривалих аварійних відключеннях від загальнодержавної енергосистеми. Проблема. Існуючі теоретичні засади проєктування мікромереж орієнтовані переважно на однофазні розподільчі мережі невеликої потужності і не враховують особливості потужних трифазних промислових мікромереж. Зокрема, залишаються невирішеними проблеми забезпечення стабільності системи в умовах низької інерції (відсутності обертових мас генераторів), реалізації «безшовних» переходів між режимом паралельної роботи із зовнішньою мережею та автономним («острівним») режимом, а також ефективного локального балансування потужності з урахуванням пріоритетності споживачів. Мета. Розроблення принципів побудови потужних трифазних мікромереж, здатних в умовах нестабільного загального електропостачання забезпечити безперебійне та високоякісне електроживлення промислових підприємств з критично важливими енергоспоживачами. Методика. Дослідження ґрунтується на системному аналізі міжнародних стандартів та сучасних публікацій у галузі мікромереж, теорії ієрархічного керування, методах комп’ютерного моделювання режимів мікромережі, а також на узагальненні досвіду проєктування, монтажу та тривалої (понад один рік) дослідно-промислової експлуатації мікромережі потужністю більше 1,5 МВА на реальному промисловому підприємстві України. Результати. Розроблено та систематизовано шість базових принципів побудови потужних промислових мікромереж. Ефективність цих принципів підтверджена успішною роботою спроєктованої мікромережі, яка включає когенераційну установку (до 1,5 МВт), дизель-генератор (до 825 кВт), сонячну станцію (72,5 кВт), чотири спеціалізовані джерела безперервного живлення загальною потужністю 1,95 МВт та накопичувач електроенергії ємністю до 10 МВт·год. Наукова новизна. Вперше розроблено принципи побудови потужних трифазних промислових мікромереж у вигляді системи шести взаємопов’язаних принципів, які на відміну від існуючих підходів охоплюють фізичні аспекти стабілізації, системні аспекти керування та якісні аспекти електроенергії (компенсацію реактивної потужності, симетрування навантаження). Запропоновані принципи призначені для мікромереж потужністю понад 1 МВА і враховує специфіку промислового підприємства. Практична значимість. Запропоновані принципи складають методологічну основу для проєктування та модернізації потужних промислових мікромереж в Україні та інших країнах з нестабільним електропостачанням. Бібл. 36, рис. 3. National Technical University "Kharkiv Polytechnic Institute" and Аnatolii Pidhornyi Institute of Power Machines and Systems of NAS of Ukraine 2026-07-02 Article Article application/pdf application/pdf https://eie.khpi.edu.ua/article/view/366079 10.20998/2074-272X.2026.4.10 Electrical Engineering & Electromechanics; No. 4 (2026); 74-83 Электротехника и Электромеханика; № 4 (2026); 74-83 Електротехніка і Електромеханіка; № 4 (2026); 74-83 2309-3404 2074-272X en uk https://eie.khpi.edu.ua/article/view/366079/351648 https://eie.khpi.edu.ua/article/view/366079/351649 Copyright (c) 2026 A. A. Shcherba, O. D. Podoltsev, N. I. Suprunovska, R. V. Belyanin http://creativecommons.org/licenses/by-nc/4.0 |
| spellingShingle | powerful electric microgrid uninterrupted power supply local power balance sources of electricity electricity storage devices Shcherba, A. A. Podoltsev, O. D. Suprunovska, N. I. Belyanin, R. V. Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title | Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title_alt | Принципи побудови потужних мікромереж для безперебійного електроживлення промислових підприємств |
| title_full | Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title_fullStr | Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title_full_unstemmed | Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title_short | Principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| title_sort | principles of building powerful microgrids for uninterrupted power supply of industrial enterprises |
| topic | powerful electric microgrid uninterrupted power supply local power balance sources of electricity electricity storage devices |
| topic_facet | powerful electric microgrid uninterrupted power supply local power balance sources of electricity electricity storage devices потужна електрична мікромережа безперебійність електроживлення локальний баланс потужності джерела електроенергії накопичувачі електроенергії |
| url | https://eie.khpi.edu.ua/article/view/366079 |
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