CHAPTER ONE

BACKGROUND OF THE STUDY

1.0  INTRODUCTION

There are many devices, such as generator, transformer etc which are usually used in a power station to generate and supply electrical power to a power system network. The three phase ac generator generates a three phase alternating voltage range between 11 and 20kv. The magnitude of the generated voltage is increased to 120kv or more by means of a power transformer. This higher magnitude of voltage is then transmitted to the grid substation by a three phase transmission line. A lower line voltage of 415v is achieved by steping down either from the 11 or 33kv lines by a distribution transformer. In these case, a three – phase transformer is used in either to step – up or step down the voltages since a transformer play a vital role in feeding an electrical network with the required voltage, it becomes an important requirement to a power system engineer to understand the fundamental details about a transformer along with its analytical behaviour in the circuit domain. A transformer, irrespective of the type, have the following characteristics, it has no moving part, no electrical connection between the secondary and primary wirings, their winding are magnetically coupled; frequency is unclogs rugged and durable in construction.