CHAPTER ONE
INTRODUCTION
1.1      BACKGROUND OF THE STUDY
It is a well known fact today that electrical power supply is not reliable. All over the world, there is a significant electrical power supply interruption. Because of these electrical power supply interruption, many electrical  instruments have this developed problems or even stopped working entirely. Hence this crippled much business thereby affecting many countries economy as Nigeria. Also there is increase in occurrence of power supply disturbance, which can be viewed as a form of power pollution. High voltage spikes and momentary voltage drops are therefore common. These power disturbance may affect the performance of of sensitive equipment in private and corporate organization causing loss of data and even damage to equipment.
In Nigeria today, it is not an overstatement to talk about the epileptic supply of electrical power. This has become the order of the day such that many Nigerians now view these power outages as “normal” and part of their daily life. A wide range of factors has been identified for this problem. They include natural disasters, vandalism, maintainability and sustainability and lack of local content. The problem of poor quality power supply cannot be properly addressed without a review of other factors such as lack of political will to invest adequately in power sector, absence of replacement policy resulting in obsolete equipment, unsustainable human capacity building and inadequate reward and remuneration system to motivate human resources to perform well.
According to the recommendation made by the institute of Electrical Electronics Engineering (IEEE), the supplies that should be available for use should be continues, uninterrupted with constant frequency and within the load determine in terms of voltage and current. These requirements have become even more relevant in view of the high sensitivity and sophistication of modern technological equipment in use today.
The progress made in developing alternate source of energy over the last decades has showed that independent power systems are not only possible but also very practical. Infact a wide variety of generating equipment is now available to allow individuals take advantage of just any renewable source of energy, for number reasons however, most of these systems produce only direct current (DC) and often do so only at low voltage. Nonetheless, it is generally agreed that the greatest and most useful form of current is the alternating current (AC) since this exists in the vast majority of homes.
Therefore, there arises the need to able to convert Direct Current (DC) to Alternating Current (AC) that will be of a constant frequency and also be used to power electrical circuits either in homes or in industries. Such electrical device is called an inverter.
An inverter is an electrical device that converts direct current (DC) to alternating current (AC), the converted A.C. can at any required voltage and frequencies, with the use of appropriate transformer, switching and control circuit. Inverters are common used to supply A.C. power from DC sources such as panels or batteries.
The electrical inverter e.g. 5KVA, 220 – 240, 50Hz is high power electronic oscillator. It is also named because early mechanical AC to DC converters where made to work, in reverse and thus are “inverted” to convert D.C. to A.C. the inverter performs the opposite function of a rectifier.