The initial cost of the power inverter system is significant higher
compared to the conventional source of power. As a result, there is need
for the performance evaluation of various power inverters in order to
determine the cost efficiency of the power inverter as an alternative
source of power. The aim of the present study is to investigate the
performance index of 3.5KVA/48V inverters for domestic source of
electric power supply. Four types of inverters (Mercury, Safer Power,
Sinergy and Su-Kam) commonly available in the market were considered.
And three performance indices (resistive load test, inductive load test
and output waveform) were used to determine the cost effectiveness of
one inverter over the other. Results showed that the Sinergy Power
Inverter has the best performance. In terms of the battery discharge
current, Sinergy is 35% (for the resistive) and 61% (for inductive test)
more efficient compared to Mercury at an output load of 1 kW.
1.1 Background to the Study
Electric power interruptions are quite common in every place,
especially after a heavy down pour or a severe storm. To counter this
power outage, a search has been to find a reliable and economical
alternative source of electricity. Although this kind of project has
been dealt with for quite a number of time but the fact still remains
that an improvement needs to be done. This in essence makes the project
topic “Investigation of the performance index of 3.5KVA/48V inverter”
purposeful and resourceful.
An inverter is a device or an electronic that converts or
inverts a direct current into a conventional alternating current. A
power inverter is a great tool used to run household / office
appliances, where there is no electricity. The input voltage and
frequency of the inverter may be fixed or it may vary depending on its
application. Inverters finds several applications of which are the
valuable speed, alternating current motors, uninterrupted power supply
etc. They can be used as the front stage of dc to dc converter. Standby
inverters are mostly used to provide emergency supply to the main
frequency (50Hz). In the event of main failure, the inverter immediately
operates with no loss of waveform. This unique ability makes it related
to an automatic change over switch but it differs in a way in that it
has a battery, which stores energy when the mains is on and gives out
energy when the mains is off while the automatic change over switch
operates on contactor (open and close).
There are many types of inverter as described in chapter 2,
but they all have the same principle of operations and it all depends on
the component used, whether with a thyristor or a bipolar junction
transistor for switching the current ON/OFF. The need for man to prevent
his activities from being interrupted in order not to render it
incomplete which may subsequently become an unfinished job (loss of
files in the computer when there is a sudden power outage) has motivated
engineers across the globe to design a device which will be more
economical, durable and efficient.
It is pertinent to note that in a well organized company in a
developing country like Nigeria, where a lot of transactions are made,
if there is an epileptic power supply, the flow of transaction will
greatly be hindered and there will be no open ground for the infant
companies to spring up and wax great. Power should not be an obstruction
between companies and their maximum profits, this in essence makes the
use of a power inverter relevant and recommended to all and sundry.
Hence, the need for the investigation of the performance index of
various inverters comes to play. And this helps to determine which
inverter is more efficient, portable, durable, and cost effective.
1.2 Statement of the Problem
The primary aim of engineers in the society is to solve the problems
militating against technological growth, provide solutions to challenges
facing humanities and bringing about efficient flow of ideals and
innovators in the world of technology throughout the society and all
nation of the earth. Inverter is that device which is being employed by
the engineers to tackle and support the power supplies. This support
comes to play when there is power outage. Immediately, the power
inverter begins to act in place of the main power. Inverter are used in
the conversion of direct current to a conventional alternating current,
but the need for a reliable and more efficient, stable power supplies
make the inverter indispensable especially in developing country like
Nigeria where there is an epileptic power supply. Hence the need for
investigation of the performance index of 3.5kVA/48V inverter in
relation to other inverters becomes vital.
Although, the electric power in an alternating current
form is very difficult to store due to power loss which are associated
with the alternating current and when converted, it can be in stored in
the battery of which can be recharged.
1.3 Aim of the Study
The aim of the study is to evaluate the performance index of 3.5KVA/48V inverters for domestic electric power supply.
1.4 Objectives of the Study
The objectives of the study are stated as follow.
- To determine the output wave form of the inverter
- To determine the battery discharging current/voltage on load and the effect of load on the inverter
- The determine the power efficiency (real-time output power ratings)
` The methods adopted to achieve the set objectives are as follows.
- The Cathode ray oscilloscope was used to measure output wave form.
- The resistive and inductive load tests were applied to determine the
battery discharging current/voltage on load and the effect of loads on
the selected inverter
- Clamp meter, amp meter and volt meter were utilized.
1.6 Scope of the Study
In this study, the capacity of power inverters considered is
3.5KVA/48V with an output of 220-230V, frequency of 50Hz. And four
different inverters vendors selected are Mercury, Safer power, Sinergy
and Su-kam. The choice of selection is based on the availability,
portability, customer patronage and assesses to parts or repair.
1.7 Significance of the Study
The study can enable:
- the individual to have basic knowledge about inverter;
- the energy consumer decide on the most economic inverter to install
- create more awareness on the use of inverter.
1.8 Arrangement of the Work
The study is divided into five chapters. Chapter one has been
discussed. Chapter two gives a description of power inverters and
battery, and what to look out for before buying inverter.
Chapter three discussed the experimental setup of the 3.5KVA/48V
inverters for various inverters, and how it was analysed. The
arrangement is based on the selected load specification of 1000VA.
In chapter four, the results of the performance of various inverter used as a case study, were presented and discussed.
Chapter five gives the conclusion and recommendation of the study.