Introduction

In this present world human beings are improving their living standards by using amazing techniques. The world abounds umpteen forms of energies .human beings are striving hard in harnessing these energies .

Energy thus serve as life blood for the growth and progress of human kind. I the bank of energies electrical energy holds first place because it is easily adoptable for human needs and interests. Energy is neither created nor destroyed but we can change from one form to other. Energy conversion takes place between well known pairs of forms given

Electrical <-->Chemical

Electrical <-->Thermal

Electrical <-->Optical

Electrical <-->Sound

Electrical <-->Mechanical

The Increasing use of electrical energy in different fields of daily life has been increased .So, vast variety of electrical machinery for the purpose of generation and utilization is required. Electrical machinery is classified as :

1. DC machines

2. AC machines

3. Special machines