Design And Construction Of A 100VA Electric Power Inverter

ABSTRACT

Power inverter is an electrical appliance that can be used with DC battery as an alternative source of energy supply in the event of power failures and energy crisis. It is cheap, clean, very conducive and silent when in operation and a very reliable source of power supply as to generator. Modern research and technologies have shown that inverter is one of the cheapest forms of energy generation. Throughout the world, it is readily available and can be partner to solar energy particularly using photo-voltaic cells (PV) or solar panel arrays, with a battery bank as a reservoir to collect and store solar energy in large scale power generation/production for rural and very remote areas’ electrification project in the Nation.

Most domestic appliances such as personal computers, television sets and lighting systems among others, operation has largely been controlled by hydro-electric power supply [National Grid]. This is not much a reliable source of energy due to the persistent power failure from our only reliable Nation Grid in the country, which has been as a result of low water level in the dam(s) during dry seasons, faulty underground cables and transformer failures.

This work is therefore seeks to use inverter with the help of 12V DC battery as an alternative source of energy in the wake up of these challenges to power household appliances.

CHAPTER ONE

1.0                                              INTRODUCTION

1.1                                        BACKGROUND OF THE STUDY

Electricity supply is one the economic infrastructural facilities that are indispensable to a nation’s economic development. The efficiency of the supply of electricity will not only influence returns on investment on existing enterprises, it also plays a major role in the creation of an economic environment which influences decisions on potential investment.

The electricity which is the main source of power for our domestic consumption, industrial development, center of learning and medical centers should really be rehabilitated into enhancement of productivity.

However power failure has resulted in people buying generators for their own daily activity. Other businesses are also not functioning due to absence of constant power supply. These are the reasons that necessitate the designing and construction of inverter and other standby system that can deliver maximum output power to the load. As society grows from simple to complex, mankind began to spread all over the earth and so it becomes necessary  to enjoy power using inverter.

Statistics have shown that the number of business that have been closed simply because of power problem and cannot be over emphasized, so mankind need inverter seriously in other to restore technology development, businesses, communications, learning center and medical centers. However, the background of the study lies within the reason why and the construction of inverter should be forwarded and factor that enhance inverter marketability.

Finally, the success of this study will be beneficial to the society at large. Mass production of inverters will lead to improve standard of living of the populace and the nation will move forward in it pursuit of technological development.

1.2                                               PROBLEM STATEMENT

As a result of continuous power failure and fluctuation in power supply by Power Holding Company of Nigeria (PHCN), sensitive appliances and system are affected by interruption power supply. Then, this project is to provide a back-up and reliable power supply of 100va to power some selected home appliances such as computers, television set, lighting systems.

1.3                          AIM / OBJECTIVE OF THE PROJECT

The aim of this project is to design and construct a circuit that will take a 12v dc input from battery and provide a 220v ac output that will be able to supply a electricity to a home. At the end of this work the student involved shall able:-

1. To design a circuit that will convert dc to ac power for various appliances used in domestic home.
2. To provide a noiseless source of electricity generation.

• To have a source of generating electricity that has no negative effect on the environment (i.e. no greenhouse effect).

1. To provide a source of electricity power with low maintenance cost and zero fuel cost.

1.4                                           PURPOSE OF THE PROJECT

The purpose of this work is to provide a means of having a backup power supply by building an electronic device or circuitry that changes direct current (DC) to alternating current (AC).

1.5                                               PROJECT MOTIVATION

Inverters are the best when it comes to back-up since they can come up very fast and they generate little or no noise unlike generator. Even in an area with constant power supply, power outage due to natural cause and faults are usually unannounced. It is therefore very important to prevent causalities and loss of goodwill by having a reliable back-up power installed.

1.6                                       SIGNIFICANCE OF THE PROJECT

In the recent years,  power  inverter has become a major power source due to its environmental and economic benefits and proven reliability.

Power inverter is produced by connecting the device on the 12VDC battery as the input to produce 220VAC as the required output. It can also be connected to solar panel.

Second, the whole energy conversion process is environmentally friendly. It produces no noise, harmful emissions or polluting gases. The burning of natural resources for energy can create smoke, cause acid rain and pollute water and air. Carbon dioxide, CO2, a leading greenhouse gas, is also produced in the case of burning fuels. Power inverter uses only the power of the battery as its fuel. It creates no harmful by-product and contributes actively to the reduction of global warming.

1.7                                              SCOPE OF THE PROJECT

The scope of this  work focused on building a conversion device. It converts fixed direct current (DC) voltage to alternating current (AC) voltage output.

Power inverters are used to power and control the speed, torque, acceleration, deceleration, and direction of the motor. The use of inverter has become prevalent in wide range of industrial applications; from motion control applications to ventilation systems, waste water processing facilities to machining areas, and many others. Though power inverters offer lower operating costs and higher efficiency, they are not without their problems.

The waveform of this work is modified sine wave. The modified sine wave output of such an inverter is the sum of two square waves one of which is phase shifted 90 degrees relative to the other. The result is three level waveform with equal intervals of zero volts; peak positive volts; zero volts; peak negative volts and then zero volts. This sequence is repeated. The resultant wave very roughly resembles the shape of a sine wave.

1.8                                         LIMITATION OF THE PROJECT

• Expensive when compared to traditional generators
• The inverter can power a few appliances for a short period
• The input is limited to 12VDC, output to 230VAC and the frequency to 50Hz

1.9                                       APPLICATION OF THE PROJECT

The applications and uses of a power inverter are as follows:

1. DC power source utilization
2. Uninterruptible power supplies

• Induction heating

1. HVDC power transmission
2. Variable-frequency drives
3. Electric vehicle drives

• Air conditioning
• Electroshock weapons

1.10                                                   METHODOLOGY

To achieve the aim and objectives of this work, the following are the steps involved.

Study of the previous work on the project so as to improve it efficiency. The block diagram and the working principle of the project was studied, followed by drafting out a schematic diagram and arrangement the entire materials / components on the vero board, testing the completed system to see if the design works and finally, implementation of design of the project.

1.11                                      PROJECT WORK ORGANIZATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to a power inverter. In this chapter, the background, significance, aim/objective problem statement, purpose, application, limitation and problem of a power inverter were discussed.

Chapter two is on literature review of a power inverter. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.