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i 1 i 2 V = N Faraday’s Law’s of Electromagnetic Induction

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i1

i2

V=N

Faradays Laws of Electromagnetic Induction

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

Faradays law

So we have the following : 1)

2)

i1

i2

i1 i2

E1

E2

E1

E2

N1: N2 Step Up N1 < N2

N1 : N2 Step Down N1 > N2

E1

E2

N1 : N2

E1

E2

N1 : N2

THE VOLTAGE MEASURED FROM THE DOT END TO THE NON DOT END IS IN THE SAME PHASE

C A

VAB

B D

C A

VAB

B D

VCD

C A

VAB

B D

VCD

Primary

Secondary

Primary

Secondary

N1 : N2 1:n

i2 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

i2 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

i2 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

EG , E1

i2 Primary Secondary

i2

EG

E1

E2

Z2

As , E1 and E2 has the same dot polarity , So E1 is in phase with E2 So in the phasor diagram

Primary

Secondary E2 Z2

EG

E1

N1 : N2 1:n

EG , E1

i2 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

E2

EG , E1

i2 Primary Secondary

i2

EG

E1

E2

Z2

i2 lags or leads by E2 depends upon the impendence i2 lags E2 if it is inductive load i2 leads E2 if it is Capacitive load

Let us consider , Z2 be the inductive Load so i2 lags E2

i2 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

E2

EG , E1

i2

i1 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

So,E2 = n E1i1 =ni2 EG , E1 E2 = nE1

i2

So,i1 = n i2

Inside the core there is a flux m linking Both primary and secondary

i1 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

So,E2 = n E1EG , E1 E2 = nE1

i1 =ni2

i2

So,i1 = n i2

According to the Faradays Law ,

= N1 j m Due to j operator m moves From E1 by clockwise of by 90 So We have in Phasor diagram

i1 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

So,E2 = n E1i1 =ni2 EG , E1 E2 = nE1

i2

So,i1 = n i2

i1 Primary Secondary

i2

EG

E1

E2

Z2

N1 : N2 1:n

The Phasor Diagram of an Ideal Transformer

So,E2 = n E1

i1 =ni2

EG , E1 E2 = nE1

i2

So,i1 = n i2

Power Handling Capacity Electrical Parameters i1 , V1 , Power , Turns (N1, N2) Mechanical or Physical dimensions Core Sizes , Sizes of wire gages etc

To determine the power handling capacity of the transformer we have to mapping the Relationship between Electrical Parameters and Mechanical dimension

the practical transformer the coils are terminated by soldering , the rectangular solid block is the core , in this case the core is CRGO( cold rolled grained oriented) silicon steel ,as the steel is conductive , we have lot of eddy currents in the solid steel , to reduce the cross-sectional area of the eddy current path , to increase the resistance for the eddy current path the lamination have been put into it , all the practical transformer has solid bulk of core is laminated , its all are pocket is vacuumed and it is varnished and its darkish color is due to the varnish coating , well you see the winding in the centre which goes to the central limb, now this consists of both primary and secondary winding the primary goes first and then the secondary

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Equipment-Gi Avw_s

All the power station are made on ground grids , the grid consists of metal rods driven to the ground and this is connected to the metallic mesh met , all this area is the same ground potential . the main reason is that for safety.

Switch Gear-1

Switch Gear-2

Transformer-1

Transformer-2

10 wdU GROUNDING ROD

evZvm

gvwUMetallic Mesh

The external metallic frame of the s/g , xformer, substation structure , relay panels and so on are solidly connected to the mesh-metgrounding straps are always are considerable current carrying capacity to provide an easy path for flow of stray current to the ground , the potential though-out the area is at the same ground potential , so providing safety for the personnel working in and around the equipment

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wKQy wewea K_v t K) Uvdigvii bgcU Rated Output `Iqv _vK wbw` Zvcgvv Rise Gi Dci hvnv KviLvbvq Kwgfve test Kiv nqwQj| L) UvdigviK (Insulation) wZ bv Ki bgcU Rated Output Gi KvQv KvwQ Output cZ nj mZKfve jvwWs KiZ ne | Ze Rated Output wewfb operating condition Gi Dci wbfI Ki , hgb - evwnii Zvcgvv, cv_wgK Loading , Cooling Provision etc. M) Uvdigvii Avqy Kg hvq hw` Dnv ekxb Overloading Kiv nq| O) KZb Overloading Kiv hve Zvnv wbfi Ki : K) Uvdigvii Byjkbi cKwZ | L) cv_wgK jvwWs | M) Kzwjs

Percentage Impedance :Dnv GKwU Uvdigvii dzj jvW Dnv Avf iwRv Ges wjKR wiqvKU Kvib fvR Wc K eySvq | ixb

Conditions of Parallel Operation of Transformers :

Transformer-1 R Y B R

Transformer-2 Y B

Transformer-1

Transformer -2

1) Polarity2) Voltage ratio 3) Percentage impedance 4) Phase Rotation / Sequence 5) Vector Group

== = = =

Polarityvoltage ratio Percentage impedance Phase Rotation / Sequence Vector Group