The quest to satisfy our need for stable power
supply in Nigeria has driven most Nigerians into an ardent search for
alternative renewable power sources. One of such major renewable power source
in use is solar energy, which is energy obtained from the radiation of the sun.
To obtain electrical power from the sun, four key
components are required to effectively and efficiently convert the sun’s
radiation energy. These four key components include:
energy-conversion system (Solar PV
modules or array)
system (Charge controllers)
storage media (Batteries)
Fig 1.1: Simple diagram of a house hold Solar Power
Fig. 1.1 above gives
the diagrammatic description of a solar power system. As can be seen from the
diagram, radiant energy from the sun striking the solar panels is converted
into DC voltage which is fed into a battery through a charge controller. The electrical
energy stored in the battery is then converted from DC to AC, and stepped up to
the voltage level required for the operation of house hold electrical
It is important to note
that to efficiently and effectively convert the DC electrical energy from solar
PV modules into AC quantity, an inverter must be incorporated into the system.
The area of contention, as regards to this project report is in the area of
selection of the most efficient and cheap solar inverter. Knowing how efficient an inverter will be can
only be determined through usage and/or testing of the inverter in question,
and further analyzing the results obtained, in order to compare them with that
of an ideal inverter. This whole idea gave birth to the topic of this project “Solar power inverters, analysis and test
It is our belief that
an inverter whose characteristics is close to that of an ideal inverter can be
regarded as a good inverter, while that whose characteristics is far from an
ideal inverter can be regarded as inefficient.
mentioned before electricity crises is a major problem in the present era. This
problem is even more critical for a densely populated poverty corrupted
developing third world country like Nigeria. A lot of people live here without
the basic facility of electricity. Daily, electricity crises and price is
increasing whereas no other solution is left for us without using the solar
power or diesel turbine to generate electricity in remote areas which seems to
be very expensive to run. Again, not only do we face electricity crisis but also,
the cost of gas and other natural resources like fuel, diesel , petroleum etc. is
on the increase, beyond the reach of the general populace. To this effect, a
system capable of not only reducing the electricity crisis but also the need
for petroleum or other natural resources used in energy generation is therefore
the desired choice in Nigeria today.
the demand for solar power generating system is on the increase, as the world
today is seeking better sources of electricity lees capable of causing damage
to the environment.
Statement of problem
report will have no understandable meaning or importance without it being able
to present solutions to some of the problems posed while embarking in a solar
power installation project, as well as provide answers to some of the questions
commonly asked by electrical engineering students when faced with solar power
system installation. To this effect, the problems/questions listed below
How do we
determine the best type of inverters from a selection provided in today’s
How do we determine
the best type of batteries required for a particular solar power system
is/are required for the determination of the actual operating
characteristics/properties of an inverter, when given an inverter whose
operating characteristics are not given?
How do we carry
out a troubleshooting operation for a faulty inverter?
How do we know
the amount of distortion introduced into the output of an inverter by the
presence of harmonics?
Aims and objectives of this study
The aim of this study
is to provide a platform for carrying out standard basic tests and analysis on
solar inverters for electrical/electronic engineering students/instructors, as
well as provide a foundation for carrying out standard comparison between
The objectives of this
study thus follow:
To provide a
platform for the selection of the best type of inverters from an available
To provide a
means for the determination of the best type of batteries required for a
particular solar power system installation
To provide a
standard list(s) of tests required for determination of the basic operating
characteristics of solar inverters.
To provide an
encyclopedia of information on solar power system for students who wish to
major in the field of solar power system installation
electrical/electronics engineering students with the solar power installation
and harvesting process.
Within a four week period, various tests
were carried out on two inverter brands. The results obtained from these tests
were recorded on a record sheet in a tabular form, graphs were plotted with the
information recorded, and comparisons were made based on the graphs obtained.
brands of inverters tested were the famous blue gate inverters and luminous
inverter technologies. The tests carried
out were repeated severally to obtain correct values. Basic tests carried out
Night time power
Generally, all tests were grouped into:
Test for input
Test for output
and other special tests.
wave form of both inverters were also observed on an oscilloscope, and
comparisons were made and recorded in chapter five (5) of this report. The
harmonic distortions were observed but not measured.
Limitations of the study
Within the course of
this project, certain problems/constraints were encountered. Some of these
problems/constraints encountered marginalized the area under study while others
prevented the complete carrying out of certain tests/test procedures. Some of
these problems include:
Poor state of
equipment; some analogue measuring equipment like the high range ammeter
available was improperly damped, making it almost impossible to read
instantaneous values of current.
There was a
shortage in the availability of high range measuring equipment at the school
lab. This restricted tests carried out to lower values. Certain tests had to be
attenuated or completely stopped when the values obtained exceeded the
deflection of analogue meters, or the range of digital meters.
of certain measuring equipment like the THD analyzer used in the measurement of
harmonic distortion. Computer programs like the PV array simulator, required to
carry out MPPT performance test was also not available.
As a result of
shortage in certain measuring equipment, the data collected were from various
measuring instrument ( analogue, digital), leading to a non-uniform measurement
of standard connecting cables
The duration for
the study, when compared to the volume of work required for completely carrying
out the project was limited.
We also had
inadequate financing as at the instant it was required