generator operation.ppt

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Schematic representation of two magnetic poles of opposite polarity, and the magnetic field between them

shown as “lines of force.”



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Schematic representation of two north poles, and the

magnetic field between them. South poles will createsimilar field patterns, but the lines of force will point

toward the poles.



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Schematic representation of a magnetic field created

by the flow of current in a conductor



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Schematic representation of a magnetic fieldproduced by the flow of electric current in a

coil-shaped conductor



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The flow of electrons inside a conductor material,for example, copper.



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• Red = North pole

• Green = South

pole

• Opposite polaritiesattract



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DC Generator



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Alternating Current (AC)

• Current is constantly changing in magnitude

and direction at regular intervals

•

Current is a function of time and usually variesas a sine function

I

t



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Revolving Armature(Low Power/Voltage)



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Revolving Field



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3 Phase



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Stator of synchronousGenerator

Finish

Start

Finish

StartStart

Finish

Phase Winding

N

S

Salient pole three phase synchronous generator



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Cylindrical rotor synchronous generator

Stator of synchronousGenerator

Finish

Start

Finish

StartStart

Finish

Rotor

Rotor winding

fed with D.C.current

Stator Winding



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F I E L D

C U R R E N T

M O T I O

N

( o f c o n d u c

t o r )

Fleming’s Right Hand Rule for generator



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Red phase = 0 VYellow Phase = -86.6 V

Blue Phase = +86.6 V

Time : t = 0

N S

Three phase voltages produced by the salient pole generator



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Red phase = 50 VYellow Phase = - 100 V

Blue Phase = + 50 V

Time : t = 30 Sec

N

S

Three phase voltages produced by the salient pole generator

Three phase voltages produced by a 4-pole



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Red phase = +86.6 VYellow Phase = 0 VBlue Phase = -86.6 V

Time : t = 120

N

N

S

S

Three phase voltages produced by a 4 pole

salient pole synchronous generator

Three phase voltages produced by a 4-pole



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Red phase = 0 VYellow Phase = -86.6 VBlue Phase = +86.6 V

Time : t = 360 N

NS

S

Three phase voltages produced by a 4 pole

salient pole synchronous generator

4-pole cylindrical rotor synchronous generator



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Stator

Winding

Rotorwinding

4 pole cylindrical rotor synchronous generator



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Three Phase

-1.5000

-1.0000

-0.5000

0.0000

0.5000

1.0000

1.5000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Sine

Sine + 120

Sine + 240



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Cut-Away View of a Synchronous

Machine



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Four Pole Synchronous Machines: (a) with Salient-Pole Rotor,(b) with Cylindrical Rotor having three Coils per Pole



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6/2005 31“Developed” view of a four -pole stator, showing

the slots, the poles, and a section of the winding.



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generator operation.ppt

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