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Solar System Inverters Types
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Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
Solar System Inverters Types
Samhar Saeed Shukir
Electrical Department, Technical Institute- Kut, Middle Technical University, Baghdad, Iraq
Corresponding Author: samharalwandi@gmail.com
ABSTRACT of the inverter is considered one of the most
Population growth and economic important factors for the success of the solar
development lead to increase the global system. The appropriate inverter is selected
energy consumption from (60) million barrels depending on the size of the solar system and
per day in 1980 to (96.5) million barrels per the way it is connected to the main grid. The
day in 2021 and consumption is expected to main types of the solar inverter will be
increase and reach to (104.1) million barrels introduced in this article.
per day in 2026. Fossile fuel causes emission
greenhouse gases such as carbon dioxide and Keywords-- central inverter, string inverter,
methane which are causes what is known as micro-inverter, inverter/charger, simple inverter,
global warming and it is expected it will be hybrid inverter, power optimizer devices
exhausted within (40-60) years. Solar energy
do not emit any pollutants and it is
permanent as the sun is always shining, so it INTRODUCTION
is necessary to develop the solar energy sector
to reduce the risk of climate change and to Inverter is a system that converts
make the air we breathe more safer, also to unidirectional voltage waveform (DC form) into
produce energy locally and reduce a bidirectional voltage waveform (AC form). In
dependence on foreign sources of energy. A general, there are seven types of inverters used
solar inverter is one of the most important in solar systems
elements of the solar electric power system. It 1. Central inverter
converts the variable direct current (DC) 2. String inverter
output of a photovoltaic (PV) solar panel into 3. String inverter with power optimizer
alternating 220V current (AC). This AC 4. Micro inverter
electricity then can be fed into your home to 5. Hybrid inverter
operate your appliances. Long lasting solar 6. Inverter with charger
power systems require a high quality inverter 7. Simple inverter
with a robust convection cooling system. Low
quality inverters have failed in generating the We will discuss about each type of
required power. The efficiency and reliability inverters used in the solar system
1. Central inverter
Figure 1: Central Inverter
24 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
These inverters are characterized by string of solar panels are connected to it to
their high capacity up to (4MW). These types of convert the continuous voltage into alternating
inverters are used in on-grid systems. In the solar voltage as depicted in figure 2.
system, one central inverter is used, where all
Figure 2: The connection of the solar panel to the central inverter
In the case of large systems, the use of of the time there is no backup central
one central inverter is the most appropriate inverter.
choice in terms of cost and ease of installation, A decrease in the performance of one of the
but the use of this type of inverter has some panels (in case it is exposed to shade) leads
drawbacks, such as; to a decrease in the power generated by the
It is difficult to maintain compared to other system. Therefore, When choosing this
types of inverters type, you must take into account the
A malfunction in the central inverter leads absence of reasons for shade such as tall
to the system being out of service, as most buildings and large trees, as well as the
solar panels should not be left for a long
time without cleaning them from the dust
2. String inverter
Figure 3: String inverter
25 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
This inverter has a lower price and easy power generated from the string will be
to maintain compared to the central inverter, so decrease, therefore, it must be ensured that there
it is the preferred choice in most on-grid solar are no shadow causes. Figure 4 presented the
energy systems. But one of the disadvantages of connection of the solar system with the string
using this type of inverter is if one of the panel inverter.
in the string exposed to the shade, the electric
Figure 4: Solar system connection with the string inverter
3. String inverter with power optimizer
Figure 5: power optimize dvice
Each solar panel is connected to the decreased performance of one of the panels does
power improvement device, which is a device not affect the performance of the rest of the
that consists of a system that raises the DC panels since the panels are not connected with
generated voltage from the panel and operats each other. Figure 6 depicted the connection of
using the (MPPT) technique. The shade or the solar system with power optimize.
26 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
Figure 6: The connection of the solar system with power optimizer devices
4. Micro inverter
Figure 7: Micro inverter
Each panel is connected to a micro- This type of inverter operates with the on-grid
inverter that converts the continuous voltage system, and due to use a large number of solar
generated from the panel into alternating panel, the system becomes costly, so this type
voltage, so the panels are not affected with each used in a small systems which contains a small
other as they are not connected to each other. number of panels.
27 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
Figure 8: The connection of the solar system with micro-inverter
5. Hybrid inverter
Figure 9: Hybrid inverter
28 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
In this type of inverters two types of solar panels is insufficient to charge the
energy sources are used, such as solar panels and batteries, the inverter charges the batteries
batteries, where a series of solar panels and a from the main grid after converting their
series of batteries are inserted into the hybrid alternating voltage to a continuous voltage
inverter, which in turn performs more than one Feeding the load with electric current in the
function; event of a power outage in the main grid
Converting the voltage generated from the If the main grid supplies the load with
panels into AC voltage electricity, the inverter will give the
Charging the batteries from the solar amperes generated from the solar panels to
panels, and if the power generated from the the main grid.
Figure 10: The connection of the solar system with hybrid inverter
6. Inverter with charger regulator(inverter/charger)
Figure 11: Inverter with charger regulator
29 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
This type of inverter performs the voltages and is used in off-grid systems and
process of charging batteries in addition to stand- alone systems. Figure 6 showed solar
converting continuous voltages to alternating system connection with inverter/charger
Figure 12: The connection of the solar system with the inverter/charger
7. Simple inverter
Figure 13: Simple inverter
This inverter converts DC voltage to AC inverter is used in stand-alone systems. Figure 7
voltage only. In this case, a charge regulator depicted the solar system connection with the
(pwm) or (mppt) must be used. This type of simple inverter.
30 Page 24-31 © MAT Journals 2021. All Rights Reserved
Journal of Volume-6, Issue-3 (September-December, 2021)
Advances in Electrical Devices
www.matjournals.com
Figure 14: The connection of the solar system with the simple inverter
CONCLUSION stand-alone solar systems, it is preferable to use
the inverter with a charger regulator to reduce
This article presents seven types of the the number of devices in the solar system and for
solar inverters; centeral inverter, string inverter, ease of installation and reduce its cost.
micro inverter, and string inverter with power
optimizer which are used in on-grid solar REFERENCES
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