The Battery Supply And Charging System Of A Transformer Less Inverter

ABSTRACT

This project is on the battery and charging systemof a transformerless inverter system. Generally, inverter is designed to meet up with the power demand in the offices, industries and in homes in the absence of power supply from the national grid. In order words the device serves as a substitute for national grid which almost monopolises the power supply to people.

A transformer-less inverter that converts direct current (DC) into an alternating current (AC) suitable for injecting into an electrical power grid without using transformer, which can be used to power appliances both in homes and industries. It is designed in such a way that it will take high voltage DC from battery and inverts it to an output of 230v, 50Hz AC, and this battery is been recharge by a charger whenever the battery discharges. The main aim of this work is to carry out a study on a battery and charging system of a transformerless inverter system

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION

1.1      BACKGROUND OF THE STUDY

1.2      PROBLEM STSTEMENT

1.3      AIM / OBJECTIVE OF THE PROJECT

1.4SIGNIFICANCE OF THE PROJECT

1.5      SCOPE OF THE PROJECT

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1      REVIEW OF RELATED STUDY

2.2      HISTORICAL BACKGROUND OF AN INVERTER

2.3      REVIEW OF RECHARGEABLE BATTERY

2.4      REVIEW OF DIFFERENT TYPES OF BATTERY CHARGERS

2.5      SWITCHED-MODE POWER SUPPLY

CHAPTER THREE

3.0     METHODOLOGY

3.1      BATTERY SYSTEM

3.2      BATTERY DIAGRAM

3.3      CHARGING SYSTEM

3.4      CHARGING SYSTEM CIRCUIT DIAGRAM

3.5      CIRCUIT DESCRIPTION

CHAPTER FOUR

4.0      RESULT AND DISCUSSION

CHAPTER FIVE

5.0      CONCLUSION

5.1      RECOMMENDATION

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, learning centres and medical centre 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.

A power inverter converts DC power, to standard AC power (alternating current). Inverters are used to operate electrical equipment from the power produced by a car or boat battery or renewable energy sources, like solar panels or wind turbines. DC power is what batteries store, while AC power is what most electrical appliances need to run so an inverter is necessary to convert the power into a usable form.

An inverter can be transformer or transformerlessbased. As the name suggests, the inverter that is not equipped with a standard step-up transformer like traditional inverter for converting low voltage AC to high voltage AC.

Transformer-less inverters utilizes high voltage DC as input which is converted to high voltage AC output by oscillators and H-bridge drivers, since there is no transformer great efficiency more than 97% is achievable, the only loss is from the MOSFETs of H-bridge. The high voltage DC source can be solar panels or battery. The battery supply system provides electricity to convert into stored chemical energy for storage in an electrochemical cell by running an electric current through it (Zhang et al, 2013).

A charging system of the inverter ensures the battery that supplies energy to the inverter is charged when the need arises. ItconvertsanACpower line voltage to a steady state DC output voltage as required by all electronic circuits. The circuit of the charger converts the available unregulated AC or DCinput to a regulated DC output. The input is taken from the AC mains and then rectified,filtered and fed to a high frequency DC-DC converter.

1.2                                                  PROBLEM STATEMENT

Traditionally, dc to ac power inversion is always achieved by using a step up transformer and this makes the whole system bulky, cost effective, heavy and inefficient due to iron core losses. The invention of transformerless power inverter came to solve this problem. Transformer-less inverter are relatively inexpensive due to absence of bulky iron core transformer which is the most expensive part of the inverter and now, there are no losses related to transformer so more efficiency. Now the inverter gets lighter and makes it portable which makes less challenging to install. The charging system of the inverter is also made transformerless which was made to overcome the bulky size of the transformer based charging system.

1.3                                           AIM AND OBJECTIVES OF THE PROJECT

The aim of this work is to carry out a study on the battery supply and charging system of a transformer less inverter. The objectives of this study are:

1. To have a wide knowledge about battery supply and charging system of a transformer less inverter
2. To study the function of battery and charging system in a transformer less inverter

• To reduce cost, size, and weight, but also increases the whole system efficiency of an inverter.

1.5                                         SIGNIFICANCE OF THE PROJECT

This study will provide a deep knowledge about battery and charger used in a transformer less inverter. The study will serve as a means of knowing the importance or function of battery and charging system in a transformer less inverter.

1.6                                                 SCOPE OF THE PROJECT

The scope of this work covers studying the general use of inverter, the purpose of having Transformer-less inverters. The function of battery and a schematic diagram of the charging system of a transformer less inverterwill also be discussed.

CHAPTER FIVE

5.1                                             CONCLUSION

5.1 CONCLUSION

This thesis was carried out to study the battery supply and charging system of a transformer less inverter. In addition, it aimed to provide solution to the epileptic nature of power supply in this country. This inverter can supply power to most household appliances for a period of time that is directly proportional to the ampere-hour rating of the battery. Finally, to achieve a longer time of power supply, battery banks are recommended.

5.2 RECOMMENDATION

1. The inverter should be design to use more batteries at a time connected in parallel.
2. The charging unit should be designed to be able to deliver a high charging current, so that batteries could be charged on time.
3. The device should be incorporated with alarm, to call the attention of the user when battery discharged.
4. The device should be design to automatically switch OFF when battery charges are below the useable capacity.