ASEMINAR ON

“SYNCHRONOUS GENERATOR (ALTERNATOR)BACHELOR OF TECHNOLOGY

INELECTRICAL & ELECTRONICS ENGINEERING SUBMITTED

BY PANKAJ CHAUDHARY

R.N.-24823

DEPARTMENTOF ELECTRICAL & ELECFTRONICS ENGINEERING SANJAY GANDHI INSTITUTEOF ENGINEERING & TECHNOLOGY

NEHRU GRAM BHARTI UNIVERSITY, ALLAHABAD

UNDER THE SUPERVISIONOF

ARUNESH DUTT (H.O.D)

SYNCHRONOUS GENERATOR (ALTERNATOR)

Contents:-

Introduction

What is the Alternators

Single Phase Alternator

Three phase Alternator

Advantages of Alternator

Synchronous Speed

Types of Construction

Use of Alternator

Specification of Alternator

INTRODUCTION:- Alternating current generating system were know in simple

form discovery of the magnetic induction of electric current.

WHAT IS THE ALTERNATOR:-

• Synchronous generator or basically case machine and

or usually called alternators rotating machine.

• A Alternator is a machine for converting mechanical

power from a rime mover to A.C. electric power at a

specific voltage and frequency.

SINGLE PHASE ALTERNATOR:-

• The two poles of the stator winding are connected to each other so

that the AC voltage are in phase so, they add as the rotor turnes it’s

poles will induce AC voltage in the stator (armature) winding.

THREE PHASE ALTERNATOR-

A three phase stator can also be connected so that the phase form a delta connection.

In the delta connection the line voltage are equal to the phase voltage but the line c/n will be equal to the vector sum of the phase c/n.

120O

120O120O

VA

VB

VC

A B CVOLTAGE

ADVANTAGES OF ALTERNATOR-

• Most alternator have the rotating field and the stationary armature.

• This generated voltage may be high as 33 kv.

• The armature windings being station ary are not subjected do vibration & centrifugal forces.

• The armature of large alternators are forced with circulating gas or liquids.

SYNCHRONOUS SPEED-

• The output frequency of an alternator depends on the number of

poles & the rotational speed.

Pf

sN120

ofPolseNoPFrequencyF

SpeedssynchronousNWhere

.

TYPES OF CONSTRUCTION-

There of two types of construction.

(1) Stator Construction

(2) Rotor Construction two type

1. Salent Pole Rotor 2. Cylindrical rotor

USE OF ALTERNATOR-

• Large Synchronous generators are used to generate

bulk power at thermal hydro & nuclear power station.

• Commonly used synchronous generator as rating of

500 MVA. Used in supper power thermal power

stations.

Specification of alternator-

• Normally alternator rating depends on load power

factor which is normally lagging for inductive loads.