CHAPTER ONE

INTRODUCTION

The Background of the Problem

Power inverter system is a unit developed for the conversion of direct current (DC) into alternating current (AC) to serve electronic and electrical appliances, such as radio sets, television sets, DVD/VCD, computer, photocopying machine etcetera and also provide lighting and power to fans. Inverter systems could be used in conjunction with the solar energy conversion system for the harnessing of solar power energy and also as vital part of uninterrupted power surprise system.

The concept and development of power inverter system because necessary of the poor national power supply system that resulted in incessant power supply and power outages. Power inverter is also found in use where there is no supply of electricity in the first place.

The Purpose/Objective/Aim of the Project

The purpose of the project is to design and construct a 500VA power inverter system for the supply of A.C power to serve load of about 400watts power (the active or real power, 500VA x 0.8 = 400 watts).

The objective of the project is to ensure that the research produce an inverter and step-up transformer that would be able to transform few D.C voltage of about 12 voltage to up to 220 volt A.C 50Hz obtainable from the national power supply. Electronic appliances designed and constructed for use in Nigeria are meant to work at the designed specification of 220/230 Volt AC, 50Hz in contrast to similar equipment meant to work in a country like Japan whose national electric power supply is 110 volt A.C., 60Hz.

The designed and constructed power inverter system in accordance with the specification of national power supply will not discriminate against any equipment nor serve only a particular electronic appliance. The inverter system will be universally accepted by any system operating in Nigeria or in countries that adopted same specification. BY this, the aim of the project design and construction must have been achieved.

Scope of the Project

This project is on the design and construction of 500VA power inverter system with an in-built battery supply. In the first place, the 12 VDC battery is not part of the system to be designed implemented. The scope of the project includes designing and deriving the component values of all the circuits involved for the implementation of this project. These components are sourced and fixed in the vero board according to the determined circuitry, wired and tested through. The circuitry is completed by the design of transformer laminations and coils or windings, packaging and clamping of these laminations to air tight condition and testing through to ensure the specified rating of 400W which will supply a real power of 500VA x 0.8.

The scope of the project also coverted testing of the entire system after packaging in a metal construction with vent that will ensure in-let of air as coolant to the transformer that is expected to generate heat while in operation including power transistors.

The power inverter system produced cannot work along wired installation of power supply from the national grid unless other units are incorporated. It works on stand alone bases where no power was extended from the national into operation intermittently.